AN APPRAISAL OF THE TAXONOMY OF THE POTAMOPHREATIC MITES OF SWITZERLAND AND OF SOME SOUTHERN AFRICAN FRESH WATER MITES (ACARI: PROSTIGMATA), by Christiaan Andries Jansen van Rens burg M .Sc.(Potch.) Thesis submitted in fulfilment of the requirements for the Degree of DOCTOR SCIENTIAE in the Department of Zoology, Faculty of Science, Potchefstroom University for C.H.E. Promoter: Professor P.A.J. Ryke Assistant Promot er: Dr. G.C. Loots .January, 197 :> C O N T E N T S PAGE INTRODUCTION ..................................................... PART I 1. MATERIAL AND TECHNIQUES 4 !. I COLLECTION LOCALITIES 4 !. I.I List of Collection Localities 5 Switzerland (Jura and Tessin) 6 Republic of South Africa (Transvaal, Natal, Cape Province and the Orange Free State 8 Rhodesia 16 South West Africa 17 1.2 COLLECTION TECHNIQUES 17 1.2.1 Lotic Habitats 17 1.2.2 Potamophreatic Habitats 17 1.2.3 Treatment of the Netted portion 18 1.3 PREPARATION OF PERMANENT MOUNTS 19 1.4 SERIAL SECTIONING AND GRAPHIC RECONSTRUCTION 21 I. 4. 1 Serial Sectioning 2 1 1.4.2 Graphic Reconstruction from Serial Sections 23 1.5 S.E.M, TECHNIQUES 24 1 . 5. 1 Fixation 25 1.5.2 Dehydration 25 1.5.3 Critical Point Drying 26 1.5 .4 Mounting 27 1.5.5 Coating 27 Continued ........ . CONTENTS •••.• PAGE PART II 2. DEFINITIONS OF THE BASIC TECHNICAL TERMS AS APPLIED TO WATER MITES . . . . . • . . . . • . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 3. GENERAL EXTERNAL MORPHOLOGY OF WATER MITES 35 3. 1 ID IOSOMA. . • . • • . • • . • . • . • • • • • . . • • . . . . . . . . . . • . . • . . . • • • • 35 3. I • I Dorsum 35 3. I • 2 Venter 36 3. I • 3 Legs 36 3.2 GNATHOSOMA 37 4. CLASSIFICATION OF THE HIGHER TAXA OF THE ACARI WITH SPECIAL REFERENCE TO THE CLASSIFICATION OF WATER MITES ............... 39 5. KEY TO THE ETHIOPIAN FAMILIES OF WATER MITES 49 PART III 6. FAMILY TORRENTICOLIDAE ..................•.••..•...•...•...... 59 6. I SUBFAMILY TESTUDACARINAE 66 6.2 SUBFAMILY NEOATRACTIDINAE 67 6.3 SUBFAMILY TORRENTICOLINAE 68 6. 3. 1 Genus Torrenticola 70 6.3.2 Genus Pseudotorrenticola •.....•............. 108 7. FAMILYHYGROBATIDAE .......................................... 114 7. 1 SUBFAMILY HYGROBATINAE I 16 7.1.1 Genus Atractides 120 8. FAMILY UNIONICOLIDAE ...•................................•..•. 143 8. 1 SUBFAMILY PIONATACINAE 145 8.1.1 Genus Newnania 147 Continued •...••••• CONTENTS •.... PAGE 9. FAMILY FELTRIIDAE 152 9. I GENUS FELTRIA • . • • • . . . . . . . . . . • . . • • . • . . . . . • . . . . . • . • . . 154 10. FAMILY ATURIDAE . . . . . . . . . . . . . . . . . . . . . . . • • . . . . . . . . . . • . . . . . . . . . . 164 IO. I SUBFAMILY ATURINAE 166 10.1.1 Genus Aturus 167 IO. I • 2 Genus Kongsbergia • . . . . • . . • • . . • . . . • . . . . . . . . . • . I 7 3 11. FAMILY MOMONIIDAE ..............................•............. 181 II.I SUBFAMILY STYGOMOMONIINAE 183 II.I.I Genus Stygomomonia 183 12. FAMILY ARRENURIDAE •. . .•. •• •. ••• .••. ..••. .. •. ••. .• .• . •••.••. .• 188 12. I SUBFAMILY ARRENURINAE 190 12.1.1 Genus Arrenurus 190 PART IV 13. CHECKLIST OF THE SWISS POTAMOPHREATIC MITES 196 14. THE ETHIOPIAN REGION AND THE DISTRIBUTION OF THE ETHIOPIAN WATER MI TES • . • • • • • • • . . . . • • • • • . • . . • . . • • • • • . • . . . • . • • . . • . • • . • . • . 200 15. CHECKLIST OF THE ETHIOPIAN WATER MITES 202 PART V 16. BIBLIOGRAPHY OF LITERATURE ON ETHIOPIAN WATER MITES 246 17. ACKNOWLEDGEMENTS ........... .......................... ........ 263 18. REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 ABSTRACT This taxonomic study of water mites is divided into five parts; Part I - Techniques, Part II - General characters and Classification, Part III - Systematics, Part IV - Checklists, Part V - Bibliography of Ethiopian water mites. The water mites studied were collected from Switzerland and Southern Africa over the past seven years. The Swiss mites were all potamophreatic and the African mites were all collected from lotic habitats. The collecting techniques are discussed. The Swiss mites were collected from 46 localities in the Jura and Tessin while the African mites come from 118 ' localities in Transvaal, the Cape Province, the Orange Free State, Natal, South West Africa and Rhodesia. The techniques of preparation of permanent mounts, serial sectioning, graphic reconstruction and Scanning Electron Microscopy are discussed. The basic terms used in water mite taxonomy are listed and defined. The general external morphology and taxonomic characters of water mites are discussed and illustrated. A survey of the classification of the higher taxa of the Acari is given and the problematic position of the water mites is discussed. Water mite genera,and to a certain extent families, are stable and well defined taxa. However, the superfamilies both in composi- tion and number, are in a fluid and taxonomically unsatisfactory state. This situation is discussed and it is concluded that the pattern of intra- relationships of water mite families and their relationships with other Acari,will appear only after investigation of features other than exo- skeletal structure has been undertaken. An illustrated key to the Ethiopian families is given. Representatives of seven families were studied, i.e., the Torrenticolidae, Hygrobatidae, Unionicolidae, Feltriidae, Aturidae, Momoniidae and Arrenuridae. In each case all the synonyms and the more important literature references are listed for the family, subfamily (where applic- able) and genus. The diagnostic characters of the relevant families, subfamilies and genera are given together with a discussion. Keys are provided for the identification of the subfamilies of the Torrenticolidae, the genera of the Torrenticolinae and the Subgenera of the genus Torrenticola. The synonomy of the genus Torrenticol a and its subgeneric division is discussed in detail. The subgenus MegapaZpis Halbert, 1944 which was ignored by other authors is here recognised and defined. Five new Torrenticola species are described - T. (Torrenticola ) bicor nis n. sp.; T. (Torrenticola) trochlearis n. sp.; T. (Monat ractides) montorosa n. sp.; T. (Monatracti des) comat a n. sp.; and T. (Megapalpis ) polelae n. sp. Torrenticola (Torrenticola) eurystoma K. Viets, 1956 is redescribed from material identified by K. Viets. Torrenticola (Torrenti- coZa) j eaneZZi (Mota~ & Tanasachi, 1947) and T. (Monatr actides) ungu~cu- lat a (Walter, 1947) are discussed. All these species are illustrated. Special attention is given to the structure of the gnathosoma. The gnathosoma was sectioned and graphically reconstructed. The subgeneric division of the genus Pseudo torrenticola is rejected and the subgenus Pseudotorrentico lella therefore falls away. Pseudotorrenticola f istula n. sp. is described, illustrated and compared with the other Pseudo t orrenticola species. A key to the Ethiopian genera of the Hygrobatinae is provided. The involved synonomy of the genus Atractides is discussed in detail. The following species belonging to the genus Atractides are dealt with; A. (Po lymegapus) po lyporus (K. Viets, 1922), A. (Atr actides ) cagiaZlensis van Rensburg 1971, A. (Atractides) Zosonensis van Rensburg, 1971, A. (Atracti des) magnipalpis van Rensburg, 1971, A. (Atractides) gi bberipa lpis Piersig, 1898, A. (Atractides) latipal pi s (Mota~ & Tanasachi, 1947). A. (Atractides) micropthalmus (Mota~ & Tanasachi, 1948). A. (At ractides ) nitraensi s Laska, 1959, A. (Atractides) pri mitivus (Walter, 1947), A. (Atractides) szalayi (Mota~ & Tanasachi, 1948). Under the Unionicolidae, Neumani a (Lemienia) agnewi Bader & van Rensburg, 1968 is the only species dealt with. Representatives of the family Feltriidae have not been recorded from the Ethiopian region. Descriptions of the following Swiss species are included; F. (Fe l tria) f ossea van Rensburg 1971, F. golatensis van Rensburg, 1971 and F. (FeZtrieZZa) airoloensis van Rensburg, 1971. F. (Feltria) oornuta pauoipora Szalay, 1946 is discussed. In the family Aturidae representatives of the genera Aturus and Kongsbergia are dealt with, i.e., Aturus lelgioensis van Rensburg, 1971, K. (Kongsbergi a) angusta Walter, 1947, K. (Kongsbergi a) peotinata Walter, 1947 and K. (Kongsbergia) dentata Walter 1947. Species groups in the genus Aturus are discussed and suggested. Stygomomonia (Stygomomonia) Zatipes Szalay, 1943 is the only species of the family Momoniidae discussed in this study. Following a study of Walter's type specimens and considerable additional material it was concluded that S. (Stygorrr:>monia) graoilis Walter, 1947, S. (Stygomomonia) jurassioa Walter, 1947 and S. (St ygomomonia) transversaria Walter, 1947, and S. (Stygomomonia) Zatipes transversaria (Walter, 1947) are variants of S. (Stygomomonia) Zatipes Szalay, 1943 and should be regarded as synonyms. One species of the family Arrenuridae, Arrenurus ('lrunoaturus) bOuJmakeri van Rensburg, 1974 is described and illustrated. A checklist of the Swiss potamophreatic mites is included. The extent of the Ethiopian region is described and illustrated with a map and the endemic water mite genera are listed. The endemic nature of the Ethiopian water mite fauna is discussed and the Ethiopian species and their distri- bution are listed. A bibliography of the literature on Ethiopian water mites concludes this dissertation. 1 INTRODUCTION The oldest water mite presently known to science, "Pr>otoarrenurus convergens, was described by Cook (1957) from miocene deposits in Western North America. This is the only fossil record of water mites. The first record of a written report on water mites was published by the Strassburger fisherman Leonard Baldner in 1666. Linne (1758) published the first scientific report on water mites. Twenty three years later the first monograph on water mites titled "Hydrachnae" by Muller (1781) appeared in which he described and illustrated 49 species so well that the majority can still be recognised. Koch (1836-1842) described many species from Germany but because he based many of his descriptions on colour differences and/or developmental stages most of these species could not later be identified. At the turn of the century two German scientists, viz., Koenike and Piersig described a large number of water mite species from Europe and Africa in papers published during the years (1881-1937) and (1892-1906) respectively. Their work initiated interest in this group among scientists, the best known being Karl Viets who published more than 240 articles and books on all aspects of water mites during the years (1907- 1960). His work is certainly the greatest contribution to Hydrachnology by any one person and nobody should even attempt to do research on water mites without his catalogue of water mites and other water mite publica- tions (K. Viets, 1955 & 1956b parts 1-3). Owing to the meticulous and conscientious work of researchers, e.g., Bader, Cook, Lundblad, Mota~, Kurt Otto Viets, and Walter, the taxonomy of water mites is well systemised albeit still fragmentary. Our knowledge of the developmental stages of water mites is mediocre. Apart from the work by Mitchell (1955), Sparing (1959), Crowell (1960), Wainstein (1962, 1963), Prasad & Cook (1972) and Davids (1973) very little has been done, in fact,the larvae of the majority of species aind even of some entire families are still unknown to science. 2 Very little has been done on the internal anatomy of water mites. The most important work has been done by Bader (1938), Mitchell (1962) and Barr (1972). Apart from these specialised investigations the internal anatomy is very superficially known. As a result of the gaps in our knowledge regarding developmental stages, internal anatomy, ecology and fossil record of these animals, it is difficult to speculate on the possible phylogeny of the group. Mitchell (1956, 1964) pointed out that comparative studies in these directions may reveal more about the affinities and possible phylogenetic inter- relationships between water mites and other acari. True water mites are restricted to fresh water except for one marine family; the Pontarachidae. Water mites have an extremely wide distri- bution and have been reported from all the continents except Antarctica. They are usually found in perennial waters of streams, rivers, lakes and ponds. In isolated cases they may occur in temporary pools. As early as 1920 Chappuis reported water mites from interstitial water from Switzerland. In later years the study of these potamophreatic (Sterba, 1964) water mites became a well established discipline in acarology. Potamophreatic mites were also described from Europe, Asia and the Americas. In this work a number of these mites from Switzerland are described and discussed. It is, however, surprising that I did not find any of these mites in South Africa in spite of a search which took me to many parts of the country over the past five years. Cook (1966) described several potamophreatic species from Liberia and, I still believe that there must be potamophreatic mites in South Africa. Franz was the first to report Ethiopian water mites, collected during his travels through Africa. The specimens collected by Franz were studied by Koenike and the results were published in 1893 and 1895. Apart from these, Koenike produced several other papers on Ethiopian water mites during the years 1893-1907. Thor (1898a, 1898b) studied the first water mites from South Africa. Valuable contributions to our knowledge of Ethiopian water mites were made bY, amongst others, Cook, Lundblad, K. Viets, K.O. Viets, Walter, and to a lesser extent Bader, Halik, Miinchberg and Piersig (See Bibliography). 3 In this study an attempt is made to give an appraisal of the taxonomy of the Swiss potamophreatic mites and of some Southern African water mites and to clarify some aspects of the taxonomy of the mites involved. It was impossible to study all the Ethiopian or even South African water mite families as this would occupy many years and many volumes. For this reason more attention was paid to some families while others have only been superficially dealt with. Representatives of the family Torrenticolidae were most abundant in the sampled streams, therefore a detailed study of a number of represent- atives of this family was made. The structure of the gnathosoma of water mites in general has largely been neglected. A detailed study of the gnathosoma of the genus Torrenticola has been undertaken and it was attempted to homologise the gnathosomal components with those in terrestrial mites. One of the deficiencies of this work is the lack of information about the developmental stages of the species discussed. Virtually nothing is known about their developmental stages and research in this direction may prove exceedingly valuable for the taxonomy of these species and of water mites in general. p A R T I 4 1. MATERIAL AND TECHNIQUES Although much taxonomic work has been done on water mites fairly little has been published on the specific methods and techniques employed in studying them. Karl Viets (1936) outlined techniques for collection, preservation and preparation of water mites for taxonomic study in his general treatment of the German species. Chappuis (1942) described a method for collect- ing potamophreatic water mites. Cook and Mitchell (1952) described various methods for collecting water mites in different habitats and Mitchell and Cook (1952) described methods and techniques for the preservation, clearing and mounting of them. Pieczynski (1961) devised an apparatus for trapping water mites living in the benthos. An improved method for sampling benthic water mites was devised by Conroy (1971). The most comprehensive survey concerning the techniques employed in the study of water mites was published by Barr (1973). The works of some researchers, in allied fields are also of interest to water mite workers, Grandjean (1935, 1949), Newell (1947, 1959), Baker & Wharton (1952), Pennak (1953), Evans et al 1961 and Kranz 1971. 1.1 COLLECTION LOCALITIES The research of this dissertation was done on material collected from Switzerland and Southern Africa. Most of the material used was collected by myself and in cases where I did not do the collection personally the name of the collector is placed in parenthesis in the list of collection localities. All the Swiss material was collected from potamophreatic habitats while the African material was collected from lakes, ponds, vleis but mostly from lotic habitats. The Swiss material was collected in the Canton Tessin in the south of Switzerland and the Canton Basel in the north. The Ethiopian material used in this work was collected from as many parts of Southern Africa as possible. Extensive collecting trips have been undertaken to various parts of the Republic including the Eastern and Western Transvaal, Natal Coastal areas, Natal Midlands, Drakensberg area, the Boland, the 5 Eastern Cape and the Southern Free State. In all, 113 samples have been taken. Samples were also obtained from Dr M. Chutter of the C.S.I.R. Water Research Institute in Durban, Dr K.M.F. Scott of the Albany Museum in Grahamstown, Dr P.G. Olivier of the Rand Afrikaans University, Johannesburg and Dr A. Bowmaker of the University College of Rhodesia, Salisbury. The Jura area is characterised by its limestone nature. Most of the specimens were collected from the Liitzel stream between Neuhiisli and Erschwil, the Lutzel between the French Border and Laufen, La Combatte and Le Golat between Delemont and Develier. Surprisingl½ virtually no potamophreatic mites were found in Kaltbrunnental, a valley, where Walter (1947) found various species. Geologically the sampled areas in the Tessin are characterised by a silicone gravel substrate. Potamophreatic mites were abundant in various small mountain streams between Losone and Golino, in the Colla valley between Tesserete and Colla and in the Camignolo valley between Tesserete and Lelgio. Two of the large rivers of the Tessin, i.e., the Ticino and the Maggia, were found to be almost devoid of potamophreatic mites. All the . localities in Southern Africa from where mites were obtained are characterised by a sandstone substrate. Most rewarding were the Natal Drakensberg area, the Eastern Transvaal and the Boland in the Cape province. Interesting to mention is the presence of a large number of Arrenurus specimens in a temporary pool in the Karroo (Collection Locality 132). 1.1.1 List of Collection Localities *T hese samples were collected by a method used by Professor D.R. Cook (Personal coll1Illunication). The sandy substrate in deep pools is scooped up several times and the resulting drifting particles are collected with a net. Many mites are procured by this method but it is difficult to decide whether the mites are potamophreatic or not. They were only regarded as such if the same species were also obtained 6 by the hole-method. All the other Swiss samples were collected by the hole-method and they are thus without doubt potamophreatic. SWITZERLAND TESSIN 1. * 27. 9. 1968 Stream by Magliaso. 2. 27. 9. 1968 Stream by Casliano. 3. 27. 9. 1968 Stream above Casliano. 4. 27. 9. 1968 Stream below Casliano. 5. 29. 9. 1968 Stream at Lelgio. 6. 29. 9. 1968 Stream at 0dogna. 7. 29. 9. 1968 Stream below Pezzolo. 8. * 29. 9. 1968 Stream between Pezzolo and Tesserete. 9. 29. 9. 1968 Stream between Pezzolo and Tesserete. 10. * 30. 9. 1968 Small stream approximately 1km above Cagiallo. 11. 30. 9. 1968 Small stream approximately 2km above Cagiallo. 12. 3. 10. 1968 Melezza River at Losone. 13. 3. 10. 1968 Melezza River 1km below (12). 14. 3. 10. 1968 Junction of the Melezza and Maggia Rivers. 15. * 3. 10. 1968 Junction of the Melezza and Maggia Rivers. 16. * 3. 10. 1968 Small stream flowing into the Maggia below (15). 7 17. * 3. 10. 1968 Maggia 700m from the Solduno Bridge. 18. 3. 10. 1968 Maggia 500m from the Solduno Bridge. 19. * 5. 10. 1968 Small stream above Casa Riposo. 21. 5. 10. 1968 Small stream above Casa Riposo . 22. *5 . 10. 1968 Small stream above Casa Riposo. 23. 5. 10. 1968 Small stream above Casa Riposo. 24. 9. 10. 1968 Small stream near Losone-Golino border. 25. 9. 10. 1968 Small stream 500m from Losone-Golino border. 26. 9. 10. 1968 Small stream near Losone-Golino border. Same as 24. 27. 10. 10. 1968 Small stream near army dog training camp IOOm from road. 28. · 10. 10. 1968 Close to (27). 29. *1 7. 10. 1968 Foss near Bedrina. 30. 17. 10. 1968 Foss near Bedrina. 31. 17. 10. 1968 Foss near Bedrina. JURA 32. 30. 10. 1968 Le Golat 500m from Delemont. 33. 30. 10. 1968 La Combatte. 34. 30. 10. 1968 La Combatte. 8 35. 20. 4. 1968 Kaltbrunnental. 36. 11. 6. 1968 Stream at Erschwil. 37. 11. 6. 1968 Stream at Beinwil. 38. 27. 6. 1968 Stream at Erschwil. 39. 27. 6. 1968 Stream above Unterwil. 40. 27. 6. 1968 Stream below Unterwil. 41. 27. 6. 1968 Stream at Unterwil. 42. 17. 7. 1968 Lutzel below the canalised portion. 43. 17. 7. 1968 Lutzel between Kleinlutzel and Laufen, 44. 14. 8. 1968 Orismiihle. 45. 18. 9. 1968 Lutzel above Kleinlutzel. 46. 27. 6. 1968 Stream below Oberwil. SOUTHERN AFRICA TRANSVAAL 47. 18. 7. 1973 Selati River near cross roads - Tzaneen and Strydom Tunnel about 43km from Tzaneen. 48. 18. 7. 1973 Stream between Strydom Tunnel and Graskop, about 32km from Graskop at Vaalhoek. 49. 19. 7. 1973 Mac-Mac Pools, between Sabie and Graskop. 50. 19. 7. 1973 Kiepersol, about 1km from Villa Sabie Rest Camp. 9 51. 19. 7. 1973 Marite River between Sabie and Bosbokrand. 52. 19. 7. 1973 Marite River between Bosbokrand and Graskop. 53. 19. 7. 1973 Bridge 2288 (1969), between Bosbokrand and Graskop at Hazyview turn off. 54. 20. 7. 1973 0hrigstad River, at bridge between Lydenburg and Pilgrims Rest. 55. 20. 7. 1973 Spekboom River at Bridge 1870 (1964), between 0hrigstad and Lydenburg. 56. 20. 7. 1973 Stream (Bridge 1872) between 0hrigstad and Lydenburg. 57. 20. 7. 1973 Stream near Lydenburg on 0hrigstad road. 58. 20. 7. 1973 Nels River at bridge and railway bridge, on Nelspruit-Sabie road near Sudwala's Kraal turn off. 59. 20. 7. 1973 Stads River at Bridge 379, between Rosehaugh and Sudwala's Caves. 60. 20. 7. 1973 Crocodile River opposite Montrose Falls Hotel. 61. 21. 7. 1973 Stream between Kaapmuiden and Nelspruit, 8km from Nelspruit at Bridge 620. 62. 21. 7. 1973 Louw's Creek, between Baberton and Kaapmuiden. 63. 21. 7. 1973 Noord Kaap River, between Baberton and Nelsprui t. 64. 21. 7. 1973 Stream near Nelspruit, on Baberton road. 10 65. 21. 7. 1973 Stream near Nelspruit on Baberton road. 66. 21. 7. 1973 Houtboschloop, between Nelspruit on Montrose Falls Hotel, just before turn off to Sudwala's Caves. 67. 21. 7. 1973 Houtboschloop - road between Rosehaugh and Nelspruit - road to Sudwala's Caves. 68. 22. 7. 1973 Elands River (Bridge 977) between Montrose Falls Hotel and Waterval Bo. 69. 22. 7. 1973 Ngodwana River (Bridge 382) on road between Montrose Falls Hotel and Waterval Bo - after Kaapsehoop turn off near Ngodwana Mills. 70. 22. 7. 1973 Stream just after paper mill on road between Montrose Falls Hotel and Waterval Bo. 71. 22. 7. 1973 Second stream after paper mill on road between Montrose Falls Hotel and Waterval Bo. 72. 22. 7. 1973 Elands River at railway bridge on detour road. 73. 22. 7. 1973 Tautesloop on Machadodorp - Nelspruit road, near Machadodorp. 74. 22. 7. 1973 Klein 0lifants River near Middleburg, Transvaal, on Machadodorp road to Belfast. 75. 10. 9. 1971 Klerkskraal Dam _(W. van der Hoven). 76. 6. 1. 1974 Potchefstroom Dam. 77. 6. 1. 1974 Noordbrug, Potchefs~room. 78. 16. 1. 1974 Boskopdam - Sluice water. 11 79. 13. 2. 1974 Fish pond at P.T.T.C. (P.D. Theron). 80. 26. 5. 1968 Montrose Crocodile River (J. Matthew). 23. 5. 1968 Boesmanspruit, Roodepoort Farm (J. Matthew). 82. 23. 5. 1968 Komatie River, Vlakfontein Farm Carolina District (J. Matthew). 83. 23. 5. 1968 Crocodile River, Elandspruit Farm, Lydenburg District (J. Matthew). NATAL 84. November 1967 Inkonjane River Zululand. 85. 14. 10. 1973 Umgeni River just below Nagle Dam weir at the low water bridge. 86. 20. 10. 1973 Stream between main road turn off and Richmond, Natal. 87. 20. 10. 1973 Stream between Richmond and Ixopo 88. 20. 10. 1973 Stream between Richmond and Ixopo. 89. Nov. 1970 Mountain pool, Drakensberg area. 90 Nov. 1970 Drakensberg area. 91. Nov. 1970 Drakensberg area. 92. Nov. 1970 Drakensberg area. 93. Nov. 1970 Drakensberg area. 94. Nov. 1970 Drakensb~rg area. 12 95. Nov. 1970 Drakensberg area. 96. Nov. 1970 Drakensberg area. 97. Nov. 1970 Drakensberg area. 98. 16. 9. 1969 Polela River at Himeville. 99. 16. 9. 1969 Umkomazane River. 100. 27. 10. 1973 Polela River, Himeville. 101. 27. 10. 1973 Polela River, Himeville. 102. 27. 10. 1973 Polela River, Himeville. 103. 27. 10. 1973 Polela River, Himeville. 104. 27. 10. 1973 Polela River, Himeville. 105. 27. 10. 1973 Cobham Forestry Station. Polela River. 106. 28. 10. 1973 Polela River between Underberg and Bulwer. 107. 13. 6. 1972 C.S.I.R. Water Research Sample. NAT 5A-D Umzimkulu River at Riverside. 108. 12. 6. 1972 C.S.I.R. Water Research Sample. NAT 6A-.!B Umzimkulu River. 109. 13. 6. 1972 C.S.I.R. Water Research Sample. NAT SB. Ngwagwane River at Riverside. 110. 14. 6. 1972 C.S.I.R. Water Research Sample. NAT llA Umkomaas River where crossed by Himeville/ Impendhl e road. 13 111. 12. 6. 1972 C.S.I.R. Water Research Sample. NAT 14A Umkomaas River/Josephine Bridge. 112. 15. 6. 1972 C.S.I.R. Water Research Sample. NAT 28A. Umzimkulu River. 113. 9. 6. 1972 C.S.I.R. Water Research Sample. NAT 40C Umzinto River - Esperanza. 114. 9. 6. 1972 C.S.I.R. Water Research Sample. NAT 41B-C Suzela River. 115. 9. 6. 1972 C.S.I.R. Water Research Sample. NAT 43B. Inkomba River. 116. 9. 6. 1972 C.S.I.R. Water Research Sample. NAT 47A-B. Amahlongwa River. 117. 13. 6. 1972 C.S.I.R. Water Research Sample. NAT 49A-D. Polela River. 118. 9. 6. 1972 C.S.I.R. Water Research Sample. NAT 52A-B. Amahlongwa River. 119. 15. 6. 1972 C.S.I.R. Water Research Sample. NAT 53A-B. Umzimkulu River. 120. 15. 6. 1972 C.S.I.R. Water Research Sample. NAT 57A. Ngwagwana River at Underberg. 121. 3. 11. 1973 Small stream at Evaton near Hillcrest. 122. 10. ll. 1973 Glernnore Beach - Intongasi River. 123. 10. 11. 1973 Port Edward, turn off to Police Holiday Resort. 14 124. 11.11.1973 Port Edward, cross roads - Port Edward/ pontoon. 125. 11. 11. 1973 16km from Port Edward on the Port Edward/Margate road. 126. 1. 12. 1973 Small stream at Evaton near Hillcrest. 127. 9. 6. 1972 C.S.I.R. Water Research Sample. NAT 60D-E. Umzinto River at Esperanza. 128. 7. 6. 197 3 C.S.I.R. Water Research Sample. NAT 76A. Indombe River. 129. 14. 4. 197 4 Polela River at Himeville. 130. 12. 4. 1974 Small streams 1n the vicinity of Bushmans Neck Hotel. CAPE PROVINCE 131. 5. 5. 1969 Kurumanoog (W. van Hoven). 132. 19. 12. 1973 Kookfonteinspruit, between Victoria West and Beaufort West. 133. 20. 12. 1973 Hex River between De Doorns and Worcester, just before De Wet Station. 134. 20. 12. 1973 Jan du Toits River between Worcester and Wolsley. 135. 20. 12. 1973 Jan du Toits River between Worcester and Wolsley. 15 136. 20. 12. 1973 Bree River at Darling Bridge. 137. 20. 12. 1973 Klein Berg River at Bridge 1949 between Gouda and Porterville. 138. 20. 12. 1973 Stream between Gouda and Porterville. 139. 20. 12. 1973 Stream just before turn off to Matjies- fontein. 140. 20. 12. 1973 Swamp at Berg River Mouth - Velddrif. 141. 22. 12. 1973 Big dam between Grabouw and Villiersdorp, just after Pass. 142. 22. 12. 1973 Stream just after Franschhoek/Villiersdorp turn off. 143. 22. 12. 1973 Swiss Farm Excelsior, Franschhoek. 144. 22. 12. 1973 Berg River between Franschhoek and Paarl. 145. 22. 12. 1973 Small stream on the mountain in Paarl. 146. 23. 12. 1973 Eerste River at Jonkershoek near Stellenbosch. 147. 23. 12. 1973 Eerste River at Jonkershoek near Stellenbosch. 148. 23. 12. 1973 Dam on road between Jonkershoek and Stellenbosch. 149. 26. 12. 1973 Small dam between Scarborough and Cape Point. 16 150. 27. 12. 1973 Elands River at divisional boundary Paarl / Worcester, just before Klip and Elands Rivers converge. 151. 27. 12. 1973 Appelbos River close to Swellendam on road to Heidelberg, C.P. 152. 28. 12. 1973 Bloukrans River on Plettenberg/Humansdorp road on Grootrivier Pass . 153. 28. 12. 1973 Stream 70km from Grahamstown on King Williams Town road. 154. 28. 12. 1973 Stream 70km from Grahamstown on King Williams Town road. (Gwama River?) 155. 10. 1. 1974 Bloukrans River, Grootrivier Pass, between Humansdorp and Plettenberg Bay. 156. 11. 1. 1974 Berg River - Wellington. 157. I. 1954 Berg River - Wellington . ORANGE FREE STATE 158. 19. 1. 1974 Stream at Ladybrand. 159. 19. 1. 1974 Leliehoek (Ladybrand) old swimming-pool. 160. 19. 1. 1974 Deep stream on Ladybrand/Clocolan road. 16 I • 20. 1. 1974 Stream at Clocolan. RHODESIA 162. 1969 Kariba Lake. 17 SOUTH WEST AFRICA 16 3. 14. Jl. 1968 Stream, Ou Brandberg, Windhoek, (P.G. Olivier) 164. 14. 11. 1968 Ou Brandberg, Windhoek, (P.G. Olivier). 1.2 COLLECTING TECHNIQUES 1.2. I Lotic Habitats Because representatives of many water mite families frequently occur in shallow, (5 - 50cm deep) relatively slow flowing streams with stony or rocky bottoms (lotic habitats) this was the type of habitat most frequently sampled. The method used for collecting mites in these streams was by netting, using a cone-shaped plankton net with a base diameter of 30cm and a height of 50cm. The loose gravel and stones were stirred up with a spade and the suspended particles netted approximately 50 - 100cm down- stream. The procedure was repeated across the stream, and several times downstream from where the previous samples were taken. Afterwards the netted portion was washed down to the bottom of the net. 1.2.2 Potamophreatic Habitats Potamophreatic water mites were collected by digging a hole in the gravel within two metres of a river, stream or brook down to the level of the soil water. The water which initially flowed into the hole was brown with suspended particles. This water was scooped out and poured through the plankton net. This procedure was repeated until the water flowing into the hole became clear. The netted portion was then washed to the bottom of the net. 18 1.2.3 Treatment of the Netted portion Washing The netted portion was placed in a container with water from the sampling locality by turning the net inside out. The contents of the container were stirred and then poured back into the net through a sieve (36 meshes/ cm2) to separate the larger particles from the finer particles which contained the mites. The material retained by the sieve was then washed several times with clear water to ensure that all the mites were washed into the net. The remaining netted portion was again washed to the bottom of the net and transferred to the container filled with water. The water in the container was stirred and the suspended particles were decanted into the net. In this way the heavy soil particles were separated from the suspended ones, which included the mites, and consequently a relatively concentrated sample of mites was obtained. The residual netted portion was then placed into a glass sampling bottle containing water from the collection locality. The samples were labelled and all relevant environ- mental conditions recorded. The samples were transported in a polystyrene box to protect them from extreme temperatures. Sorting In the field each sample was poured into a white enamel tray containing I - 2cm of clear water. As soon as the debris had settled the mites began moving in their characteristic manner. Unlike most of the other aquatic fauna, like ostracods, ephemeropteran larvae and notostracans which swim with jerky movements, the mites could be recognised easily by their smoother, undulating swinnning movements. The mites were removed by me~ns of a small glass dropping pipette (medicine dropper) to glass collecting vials, 50 x 12mm, with polythene tops. The specimens were preserved in Koenike's fluid. Further sorting was carried out in the laboratory under a binocular stereo-microscope. The specimens were separated into genera or at least families with the aid of the stereo-microscope. The sorted material was transferred to microvials, 30 x 6 nnn, with polythene tops. These micro- 19 vials with the sample labels, were placed within the collecting vials mentioned above. The material was then ready for later study. The f ormula of Koenike's fluid is: Glacial acetic acid JOOml Glycerine (96%) 500I;tl. Distilled water 400ml 1.3 PREPARATION OF PERMANENT MOUNTS Detailed examination of the specimens involved clearing, dissection and the preparation of permanent mounts. For these techniques the following instruments were used: a pair of very fine forceps for the general handling of specimens; a fine camel hair brush for transferring specimens or parts thereof; two fine needles with hooked points for dissection and orientation. Tungsten wire needles were used for two reasons; firstly they are relatively strong and inflexible and secondly they can be sharpened to a very fine point by corrosion in heated sodium nitrite (NaNo ) (Evans et aZ. 1961). 2 Clearing the specimens was accomplished by heating the specimen in a drop of lactic acid on a cavity slide over a spirit flame. This procedure proved satisfactory, especially with dissected specimens. In species where an entire dorsal shield was present most of the internal organs were removed mechanically with the needles. In more difficult cases, however, chemical removal with Nesbitt's fluid, 5% KOH or Andre's fluid was successful. The formulae for these reagents are: Nesbitt's fluid (Evans et aZ ., 1961) Chloral hydrate 40g Distilled water 25ml Hydrochloric acid (IN) 2,5ml 20 Andre's fluid (Mitchell & Cook, 1952) Acetic Acid (glacia1) 50ml Chloral hydrate 50g Distilled water 50ml Dissection of representatives of most families was necessary for taxonomic study. This was performed with needles on a cavity slide under the stereo-microscope. A Schott lamp with a flexible fibre-glass extension supplied adequate light for delicate dissections under high magnifications. Dissection consisted of removing the dorsum where possible, the gnathosoma with the palps intact, the ejaculatory complex and the legs. To remove the dorsal shield two needles were inserted on opposite sides in the dorsal groove between the ventral and dorsal shields. The dorsal shield was removed by holding the specimen down with one needle and then gently pulling the dorsal shield off with the other. After removal of the dorsal shield the internal organs removed by gentle scraping. The gnathosoma was removed by forcing it out of the camerostome from the inside with the hooked needle, while holding the venter down with the other needle. This method obviated possible damage to the gnathosoma. The ejaculatory complex was removed by severing it at its base with a needle. The legs were detached by inserting a needle at the base and gentle pulling. By dissecting in this way most of the relevant taxonomic characters could be studied in every specimen. However, one disadvantage of this method was that the arthrodial membrane between the dorsum and venter was usually damaged. Permanent preparations were necessary because many characters could be observed only under oil iilllllersion. The dissected parts were mounted in poly-vinyl alcohol (PVA), a water soluble mountant. PVA proved to be superior to Hoyer's fluid because it did not discolour or crystallise and is more soluble in water than Hoyer's fluid. PVA had the advantage, in that permanently mounted specimens could be removed from the slides and the PVA redissolved in water. The same specimen could then be used for Scanning Electron Microscope study by merely dehydrating in a series of alcohols. The formulae of these two mountants are the following: 21 Heinz' Modified PVA medium (M.K.P. Meyer, 1966) Polyvinyl Alcohol JOg Distilled water 4O-60ml Lactic acid (cone.) 35ml Glycerine 10ml Aqueous phenol solution (1 ,5%) 20ml Chloral hydrate 100ml Hoyer's Medium Lactic acid (cone.) 2Og Distilled water 100ml Gum arabic 3Og Chloral hydrate 2OOg Glycerine 2Og To make the study of all taxonomic characters possible it was important to orientate the dissected parts. This was accomplished by placing each part in a separate tiny drop of PVA in the correct position on the slide. After the parts had set in place (two to three hours) sufficient additional mountant was added and covered by a 12mm diameter No. 1 cover- slip. The preparation was then placed on a slide warmer to dry for a week at ca. 40°c after which the coverslip was ringed and sealed with nail polish. 1.4 SERIAL SECTIONING AND GRAPHIC RECONSTRUCTION 1.4. I Sectioning Wax embedding and ordinary microtome sectioning are unsuitable for the study of small, heavily sclerotised arthropods. The size of water mites makes orientation in wax very difficult, if not impossible. Sections Sµm (approximately the minimum thickness which can be obtained with wax sections of chitinised forms) are usually too thick for the study of the minute organs involved. The heavily sclerotised integument of the mites is extremely hard and the integument has to be de-chitinised to make it 22 compatable with the hardness of the wax. As most of the structures studied are chitinised this method is unsatisfactory. Epoxy resin was therefore used for embedding and sections were made with an ultra- microtome. The living mites were killed and fixed in a cold gluteraldehyde solution (2% gluteraldehyde in phosphate buffer) for 1-2 hours. To remove any excess fixative the specimens were transferred to the phosphate buffer (2,26% NaH2Po4 and 2,52% Na0H mixed in the ratio Na0H: NaH Po 1:4,877-2 4 pH 6,8 - 7,6) and left for 1 hour. This step was repeated twice more. Post fixation was done with buffered osmiumtetraoxide (0,1g Oso - 4,5cm3 4 phosphate buffer+ 0,5cm 3 water) for an hour. The specimens were then dehydrated through a series of alcohols (Ethanol). 30% Ethanol in water 5 min 50% Ethanol ~w~~ 5 min 70% Ethanol in water 20 min 85% Ethanol in water 20 min 95% Ethanol in water 20 min 100% Ethanol 50 min 100% Ethanol 50 min After dehydration the specimens were soaked in propylene oxide (1,2 - epoxypropane). As the propylene oxide is extremely volatile,care must be taken not to shake the container. After 10 minutes the fluid was removed. Embedding material mixtures A (Epon 812 - 62cm3 + DDSA - 100cm3) and B (Epon 812 - 100cm 3 + MNA Hardener - 89cm3 ) were mixed in equal amounts. Then 100cm3 of the 1:1 A:B mixture was mixed with 2cm3 DMP 30 and an equal volume of propylene oxide (102cm3) was added. The specimens were left in the mixture for one hour after which they were taken out and air- dried on filter paper. At this stage the capsules were prepared for embedding. 100cm3 of the 1:1 AB mixture was mixed with 2cm3 DMP 30. The shallow embedding trays 23 were filled about half full with the mixture and left to dry. The air-dried specimens were placed on the hardened layer in the embedding tray in a drop of Epon-gel. At this stage the specimen was orientated. It was then left to harden in the correct position for about half an hour. The label-strips were inserted and the capsules filled completely with the Epon-DMP 30 mixture and left to harden for 12 hours at 60°c. 1.4.2 Graphic Reconstructions from Serial Sections To determine the inner structure of the gnathosoma of Torrenticola a simplified graphic reconstruction method as described by Pusey (1939) was used. This method involved drawing certain sections of a full series at regular intervals. The gnathosoma was graphically reconstructed from the drawings thus permitting some or all of the structures to be illustrated f rom a number of views. As the gnathosoma was ca. 200µm long, it was cut transversely at l,5µm. Because of the smallness of the gnathosoma and the internal structures, a reconstruction at 1000 diameters was made. Depending on the i ntricacy of the structures to be reconstructed, one must decide at which intervals sections should be drawn. If changes in the structure follow each other closely the frequency of the drawn sections should be increased. In order to determine the plate thickness and the frequency of the sections to be drawn the following formula was used: thickness of section (µm) x No. of section x magnification 1000 Applied to the serial sections of the gnathosoma the following values were operative: 4 X 100 = 6tmn = plate thickness 24 Every fourth section of the series was drawn and ultimately reconstruct- ed on a graph grid of 6mm per section drawn. The relevant sections were drawn on thin typing paper using a B - 2B pencil. Each drawing was serially numbered and coded, indicating the slide, number of the row of sections, and the section number of that particular row for easy reference. A tracing box, covered with a sheet of glass was used to pile the drawings. The first (or the last) drawing of the series was placed on the glass sheet and flooded with xylene. This renders the paper transparent but leaves the pencil lines visible. The next drawing 1n the series was then placed on top of the first and moved until it gave the "maximum fit" with the details of the drawing below. Each successive drawing was added, together with xylene, until a pile of transparent papers had been assembled. After twenty drawings (half of the total number of drawings) had been piled three reference holes were made by using a punch. The last three sheets of the first pile were used as reference for the next 20. The holes in this second pile were punched in different places. There- after the sheets of drawings were spread out to allow the xylene to evaporate. A large sheet of graph paper was pinned squarely on to a drawing board and the first drawing was placed on the right of the graph paper. The holes in the paper with the drawing were then marked on the graph paper. These provided a fixed position for the first twenty drawings. The 18th drawing with the three original, and the three additional holes - which were marked on the graph paper - provided the fixed position for the subsequent drawings. The magnified drawings of the transverse sections were then, with the aid of a T-square, projected graphically in sequence to reconstruct an enlargement of the original structure. I • 5 SCANNING ELECTRON MICROSCOPY TECHNIQUES Scanning Electron Microscopy has not been widely applied in the study of water mites. The scanning electron microscope (S.E.M.) has been designed for detailed studies of surfaces - be it inorganic or organic. 25 In the taxonomy of water mites where external integumental structures are almost exclusively used, the S.E.M. proved to be an invaluable supplementary instrument. Special treatment of biological specimens is necessary to prepare them for S.E.M. investigation. The specimens must be treated to preserve their natural shape and surface topography and to avoid the formation of artefacts. In water mites with a _heavily sclerotised integument in the form of integumental shields, e.g., the Torrenticolidae and the Aturidae, very little preparation is necessary but in soft bodied forms like the Hydrachnidae, Pionatacinae and Hygrobatidae,careful preparation is required to prevent distortion of the idiosoma. 1.5.1 Fixation Ideally, fresh, undamaged material for S.E.11. studies should be specially fixed in either a saturated picric acid solution for 24 - 72 hours or in a formal-saline solution (10ml formalin+ 0,9g NaCl made up to 100ml with distilled water). Preserved material is usually partially dehydrated and consequently distorted to some degree. This does not happen in heavily sclerotised forms where the shape of the integumental elements is not affected by dehydration. The idiosoma in soft bodied forms, however, has to be expanded to assume its natural shape. This can be achieved by placing the specimen in 5% lactic acid or 5% glacial acetic acid for 30-60 minutes. After the normal body shape has been restored the specimens may be fixed as indicated above. 1.5.2 Dehydration Specimens were dehydrated by taking them through a series of alcohols (ethanol) viz., 35%, 50%, 90% (30-60 min) 2 x 100% (60-120 min), then to clear them and to harden the tissues, the specimens were treated with absolutely water-free Xylol for 30-60 minutes. 26 To replace the xylol (and all other fluids) in the specimens, they were transferred to a series of iso-amylacetate (BDH product) 10%, 30%, 70% in ethanol, JOO% for+ 20 min in each concentration after which they were transferred to fresh iso-amylacetate. Iso-amylacetate was used because it is replaced by co2 during the process of critical point drying. The process can be interrupted at this point and the material may be stored in iso-amylacetate. Heavily sclerotised specimens and integumental elements can be mounted for coating immediately after dehydration and need not go through the process of critical point drying. 1.5.3 Critical point drying Critical point drying is a method of drying tissue without collapsing or distorting the specimen. This is accomplished by eliminating the surface tension forces which are responsible for damaging the tissue during drying. At the critical point (i.e., of temperature and pressure) of a liquid/gas system no surface tension forces are present because the densities of the liquid and the gas are equal then. Critical point drying is done in a special apparatus which consists of a pressure chamber with an integral water jacket for heating and cooling. Attached to the chamber are four pressure control valves, a thermometer and a pressure gauge. At one end of the pressure chamber is a window for viewing the process. At the opposite end is a removable access door for the specimen holder. The specimens containing the iso-amylacetate are placed in the pressure chamber. Liquid co2 is then circulated through the chamber to remove all the air and other fluids from the chamber. After 15 min of CO circulation 2 all the valves are closed to give the co2 time to penetrate the tissues of the specimens. After 60 min liquid co is again circulated for 15 min 2 through the chamber. The valves are again closed and the temperature is raised to 40°c by circulating hot water through the surrounding water jacket. At 34°c the fluid co goes over to the gaseous state without any 2 27 surface tension. After 5 min.the exit valves are slowly and carefully opened to allow the gaseous co2 to escape. Care must be taken to let the gas out slowly enough to prevent condensation of moisture on the tissue because of lowered pressure. The specimens are now ready for mounting. 1.5.4 Haunting The dried specimens were mounted on circular stubs. White nail polish was used as this dries relatively slowly in comparison with other reconnnend- ed mountants such as "Aquadac" and "Silverdac". The gnathosoma was removed and mounted vertically. The idiosoma was mounted in different ways so as to make dorsal, ventral and lateral examination possible. In the case of the Torrenticolidae the dorsum and venter were separated and mounted next to each other. This made examination of the venter as well as the dorsum of the same specimen possible. 1.5.5 Coating The mounted specimens were coated with a thin layer (:!:. 1.0nm) of a 60:40 gold-palladium alloy or with aluminium. All specimens were coated at least twice and when excessive charging showed an additional coating was applied. Coating was done in a Balzers vacuum plant under high vacuum (I0-5 torr). In this vacuum plant the angles of the stub can be changed and the stub can be rotated to ensure even deposition of the coating medium. The coated specimens were examined with the Cambridge Instruments Steroscan Mk II Scanning Electron Microscope. p A R T II · 28 2. DEFINITIONS OF THE BASIC TECHNICAL TERMS AS APPLIED TO WATER MITES (Adapted from Cook 1974) ACETABULAR PLATES. Sclerites associated with the genital field which bear the genital acetabula. These are usually immovable but in the Limnesiidae may function as do the genital plates of the more primitive water mites. (figs. 1, 28, 40). ACETABULUM (ACETABULA). Special small cup-like structures associated with the geni tal field. Function not definitely known, but previous work indicates they may be either secretory or sensory. Acetabula usually lie on acetabular plates but may also lie in the gonopore (in which case they are often elongated) or may be scattered in the integument surrounding the gonopore. Occasionally the acetabula are stalked but are usually sessile (figs. 1, 11, 21, 39, 41). AMBULACRUM. Terminal appendages of the tarsi of the legs. It usually consists of two claws which may be subdivided into clawlets (figs. 50, 51). The ambulacrum may occasionally be absent from all or some of the legs (fig. 26). ANCHORAL PROCESS. Posteriorly directed apodemes of the gnathosoma. Sometimes referred to as gnathosomal apodemes. APODEME. A term used in all arthropods for an internal projection of the thickened cuticle. ARTHRODIAL MEMBRANE. An area of the integument connecting heavily sclerotised areas of integument. This is a general term used in all arthropods. BODY PORES. Small circular areas of thin integument (of varying diameters) in heavily sclerotised water mites. Their function is to facilitate gas exchange, which would be difficult if the integument were uniformly thick. Pores are always present in heavily sclerotised forms (plate IVa). 29 CAMEROSTOME. An area of heavy sclerotisation which more or less completely surrounds the gnathosoma. There may be heavy sclerotisation ventral to the gnathosoma in mites without a camerostome. If a true camerostome is present, there must be heavy sclerotisation, dorsal, ventral and lateral to the gnathosoma to form a tube (fig. 110). CAUDA. A posterior extension of the body which is more or less distinct- ly set off from the remainder of the body. It is typical of males of the Arrenurinae, but is occasionally present in a few genera in other groups (plate VIII b, f). CHELA. The pointed, terminal segment of the chelicera (fig . 135). CHELATE. Referring to a condition of the palp in which the dorso-distal end of the fourth segment extends beyond the insertion of the fifth segment. The fifth segment is able to fold against this extension to form a pincher-like appendage (figs. 12, 13). CHELICERA (CHELICERAE). The most anterior of the appendages. It is typically two-segmented but occasionally there is fusion of these two segments. The chelicerae are housed in the gnathosoma in water mite nymphs and adults (figs. 31, 59, 135). CLAWLETS. Claw-like subdivisions of the ambulacral (tarsal) claws (fig. 51). When clawlets are absent (fig. 50) the claws are said to be simple. CONDYLES. The heavily sclerotised points of articulation between the leg and trochanters. They are used taxonomically only with the area of insertion of the fourth leg (fig. 35). COXA (COXAE). The most proximal of the leg segments. In water mites it is greatly expanded and is normally thought of as a body sclerite. The coxae may be so expanded as to occupy most of the area of the venter (figs. 16, 24, 45, 49). COXAL GROUP. In general, the first and second coxae are fused on their respective sides (anterior coxal groups) (fig. 55) and the third and 30 fourth coxae are fused on their respective sides (posterior coxal groups). When the coxae are separated medially there are four coxal groups (fig. 18, 20). Occasionally, the anterior coxal groups may be fused medially to give three coxal groups, or all may be fused into a single group (fig. 24, 42). DORSALIA. Small dorsal sclerites which lack associated setae or glandularia. Their main function is to provide a firm attachment site for the dorsal muscles. In connnon usage, the term platelet is used interchangeably. DORSAL FURROW. The narrow area (usually circular) of soft integument separating the dorsal and ventral shields (fig. 179). The dorsal furrow may in some cases be peripherally situated. DORSAL SHIELD. A single large dorsal sclerite, or two or more smaller (but closely fitting sclerites), which occupy the dorsum and are set off by a distinct dorsal furrow. DORSOCENTRALIA. Paired dorsalia or platelets which are located relatively near the midline. These are especially important in the classification of certain hydryphantid genera. DORSOLATERALIA. Paired dorsalia or platelets which are more lateral in position than the dorsocentralia. EJACULATORY COMPLEX. The term used by Barr (1972) for the internal sclerites (and associated structures) of the male reproductive system in water mites. The terms penis or penisgerust have formerly been applied to the structure. EPIMEROGLANDULARIA. Terms applied to two pairs of glandularia which are closely associated with the coxae. Epimeroglandularia I are located between the second or third coxae. They may be free or variously fused with either the second or the third coxae. Epimero- glandularia 2 are typically located between the genital field and the fourth coxae but may shift laterally or even far forward. 31 EXCRETORY PORE. (Often called the anal pore). Posterior opening of the digestive system. However, as the hindgut of the water mites has lost its digestive f unction and is now strictly an excretory organ, the first term is preferable. EYE CAPSULE. Distinct sclerites which house the lateral eyes (fig. 7). FRONTAL PLATE, A median, unpaired plate located near anterior end of dorsum. It gets its name because it usually bears the median eye (frontal organ), but the name is also applied to a sclerite in this position even if the median eye is abs·ent. FRONTAL ORGAN. Another name for median eye. GENITAL ACETABULA, Another name for acetabula, GENITAL BAY. Area between the posterior coxal groups into which the genital field projects. GENITAL FIELD, Term used for the entire genital area, It includes not only the gonopore, but also the area covered by the genital acetabula. The genital field is usually well delineated by the acetabular plates, but when the latter are absent it may be a rather diffuse area (fig. 11). GENITAL PLATES. Paired sclerites which are movable (at least primitively) and cover the gonopore when closed (plate IV c, d, e). In most cases, the genital plates do not bear acetabula but actually cover the acetabula (which lie associated with the gonopore) when closed. GLANDULARIUM (GLANDULARIA). Special paired glands each of which has an associated seta. Usually the gland and seta share a common sclerotised base but the gland and seta are on separate sclerites in the Hydrovolziidae. GLANDULA LIMNESIAE, Glands or glandularia associated with the posterior coxal group in the Limnesiidae. GNATHOSOMAL BAY. The U-shaped or V-shaped area between the first coxae in which the gnathosoma lies. 32 GNATHOSOMA. Anterior trophic sensory body region of multiple origin comprising mouthparts, chelicerae and palps. GONOPORE. External opening of the reproductive system. HYPOSTOME (ROSTRUM). A narrowed antero-ventral projection of the gnathosoma. LATERAL EYES. The two pairs of eyes typically located antero-laterally. The lateral eyes may be in capsules, the lenses may be associated with the integument and sessile, or the lenses may be located beneath the integument. The eyes may have completely disappeared in some of the interstitial water mites. In members of the Eylaoidea, the lateral eyes have shifted medially and lie on a common sclerite (figs. 7, 19). MEDIAN EYE. The single unpaired eye occasionally present in the more primitive water mites. It may or may not contain pigment and it may or may not lie on a frontal plate (median eye plate). Also called a Frontal Organ. P-I (P-II, P-III, P-IV, P-V). Convention used for describing palp segments. P-I would be the first segment, P-V the termi~al segment. P-I, trochanter; P-II, femur; P-III, genu; P-IV, tibia; P-V, tarsus (fig. 1). PALP. (Pedipalp not used with the water mites). The second pair of appendages which are attached to the gnathosoma. See immediately above for system used in describing segment number (figs. 6, 12, 13, 23, 29, 48). PETIOLE. A small projecting sclerite located at posterior end of body in males of certain water mites. It is especially common among males of the Arrenurinae (plate VIII f). PHARYNX. In water mite taxonomy the term pharynx is applied to the more heavily sclerotised portion of the pharynx -- the ventral portion of the pharyngeal pump. 33 PLATE (PLATELET). A general term for secondary sclerites of various types and sizes. It may be the same as dorsalia or ventralia or may be applied to expanded setal bases or glandularia bases. There is no clear-cut distinction between a plate and a platelet. In general a plate is a large sclerite and a platelet is a small sclerite, but the intermediate condition would be hard to define. POLYACETABULATE. Bearing numerous genital acetabula, usually seven or more pairs, but there may be cases when the term is used when more than four pairs are present (figs. 28, 32, 35, 44, 45). PORES. The same as body pores. POSTFRONTALIA. The most posterior of two pairs of dorsalia located in the median eye region (or anteriorly in those forms which lack a median eye). The postfrontalia and prefrontalia are often expanded and fused to form the frontal plate. POSTGENITAL SCLERITE. A median sclerite located at the posterior end of the gonopore. It is usually present in females (fig. l) but 1s often fused with the acetabular plates in males. In mites with a terminal gonopore, the postgenital sclerite will be dorsal in position. POSTOCULARIA. The most posterior of two pairs of setae with their associated setal bases, located in the anterior portion of the dorsum. There are no glands associated with the postocularia. PREGENITAL SCLERITE. A median sclerite located at anterior end of gonopore (fig. 1). It is often fused with the acetabular plates in males. In mites with a terminal gonopore, the pregenital sclerite will be ventral in position. PREFRONTALIA. The most anterior of two pairs of dorsalia located 1n the median eye region. See Postfrontalia. PREOCULARIA. The most anterior of two pairs of setae with their associated setal bases located at anterior end of dorsum. There are 34 no glands associated with the preocularia. PROJECTION (PALP). Chitinised protuberance without a clearly demarcated base (plate V c, d, e, plate VII). PYGAL LOBES. Posterolateral extensions of the male cauda in members of Arrenurus spp. (Plate VIII f). SECONDARY SCLEROTISATION. Body sclerites other than the coxae, capitulum, genital field and glandularia bases. The term is usually used in mite groups in which the individuals are typically soft bodied for the species which exhibit increased sclerotisation. SPINE (PALP). Heavy stout seta with a distinct setal base (fig. 106). SWIMMING HAIRS (SWIMMING SETAE). Long hair-like setae,which aid in swimming, attached to the distal segments of the legs (fig. 30). UNCATE. In water mites, referring to a condition_ of the palp in which the ventral portion of the fourth segment is greatly expanded and the fifth segment is able to fold against this expanded portion (figs. 52, 53). URSTIGMA. A pore-like structure which lies between the first and second coxae of most water mite larvae. It is absent in the Hydrovolzioidea and its function is not known in other water mite groups. VENTRALIA. The ventral equivalent of the dorsalia (see definition of the latter). VENTRAL SHIELD. The heavily sclerotised venter in which the coxae and genital field fuse with secondary sclerotisation to form a single ventral sclerite or a series of closely fitting sclerites. VESICULAR SETAE. Hollow, bladder-like structures associated with the genital cleft in Aturus-males (figs. 180, 181). 35 3. GENERAL EXTERNAL MORPHOLOGY OF WATER MITES Water mites are small aquatic arthropods ranging from 0,1 - 4nnn in length. The body is divided into two tagmata, i.e., the antero- ventrally situated gnathosoma and the posterior idiosoma. That part of the idiosoma to which the legs are attached is sometimes referred to as the podosoma. The sclerotisation of the integument varies from soft and pliable to extremely heavily sclerotised. 3.1 IDIOSOMA (fig. 1) The idiosoma exhibits no external segmentation. The shape of the idiosoma ranges from globular to dorso-ventrally flattened or laterally compressed and from round to antero-posteriorly elongated . Glandularia, special glands each with an associated seta, occur variously distributed over the idiosoma. Where the idiosoma is covered with dorsal and ventral shields the two shields are separated by the dorsal furrow, which is dorsally situated as the name indicates, but it may occasionally be lateral in position. 3. 1, 1 Dorsum The dorsum may be furnished with glandularia only or associated with platelets variously patterned through degrees of fusion, the ultimate being a single dorsal shield, Special systems of nomenclature have been developed to describe the dorsum in families such as the Terato- thyasidae, Torrenticolidae, Feltriidae and Aturinae (see figs. 57, 166, 179). A pair of eyes is situated antero-laterally on either side of the dorsum. In some cases the lateral eyes are situated close together, e.g., Diplodontus and Limnesia . In members of the Eylaoidea the lateral eyes have shifted medially and are situated on a single median sclerite (fig. 7). In some genera, e.g., Hydrachna a single median eye or frontal organ is situated between the lateral eyes. 36 3 . 1.2 Venter (fig. l; plate I a, c, e) The venter also exhibits various degrees of sclerotisation but in the case of the venter, as distinct from the dorsum, the sclerotised coxae have become fused with it. The coxae may be expanded to such an extent that they cover the major part of the venter. In general the first and second coxae, and the third and fourth coxae of both sides are fused to form the anterior coxal group, and the posterior coxal group, respective- ly. Therefore, if the coxae are separated medially there are four coxal groups. Occasionally the anterior coxal groups may fuse medially to form three coxal groups or all the coxae may be fused to form a single group. The coxae are variously ornamented and furnished with setae and glandular - ia. The anterior pair of coxae are indented to form the gnathosomal bay, into which the gnathosoma fits. The genital field is situated posterior to the coxae, very often in an indentation bordered by the posterior coxae . The genital field consists of the gonopore, the acetabula, the genital plates and/or acetabular plates. The latter two structures may be variously reduced or absent. The acetabula, small cup-like structures, probably sensory in function, may be situated in the gonopore or on acetabular plates or free on the integument in the genital field. The acetabula may be sessile or stalked and variable in number. They are present in all water mite superfamilies except the Hydrovolzioidea. In most water mite families the gonopore is covered by a pair of genital plates. They may be movable and in some families, e.g., the Hydryphantidae, they carry acetabula. The venter, behind the posterior coxal group may be variously furnished with setae, glandularia and platelets. The excretory pore, often surrounded by a sclerotised ring, is situated posterior to the genital field. In some cases the excretory pore may be situated postero-dorsally. In some genera, e.g., the males of Arrenu.rus and Axonopsalbia the idiosoma carries a posterior projection, the cauda, which is associated with the genital field and distinctly demarcated from the rest of the body. 3.1.3 Legs (figs. 1, 68, 69, 70, 71) All adults and nymphal stages have four pairs of legs used for walking or swinnning. The larvae have three pairs of legs. The legs are composed of six segments distal to the coxae. These segments are homologous with P-V -IV I GNATHOSOMA ANTERIOR COXAL GROUP COXA III POSTERIOR COXA IV COXAL GROU1 POSTERIOR APODEMES 0 THE FIRST COXAL GROU _______ pi--1 PREGENITAL SCLERITE nn.----+-ACETABULAR PLATE POSTGENITAL SCLERITE IV-LEG-3 GLANDULARIUM ACETABULUM 1 IV-LEG-5 IV-LEG-6 Fig. I. Atractides sp. - female 37 the trochanter, basifemur, telofemur, genu, tibia and tarsus of terrestrial mites and are numbered from proximal to distal with Arabic numerals. The legs are numbered from anterior to posterior with Roman numerals. The tibia of the second leg would therefore be referred to as: II-Leg-5. The tarsus terminates in the ambulacrum. Occasionally the ambulacrum may be absent from some or all of the legs. The ambula- crum usually consists of two bifurcated claws. According to Evans et al (1961) ambulacrum primitively consisted of three claws but the reduction of the median claw resulted in the bidactyl condition. In Torrenticola a number of vermiform projections are situated at the base of the ambula- crum. These may be remnants of an empodium. The ambulacral claws consist of a proximal flattened portion and the two distal clawlets. The ambulacrum can be folded back into a dorsal recess in the tarsus. The three anterior pairs of legs are usually dorsally attached to a ledge formed by the lateral projection of the three anterior pairs of coxae. The fourth pair is ventrally attached to the fourth coxae. The legs are always furnished with setae, which may be long slender swimming setae (fig. 30), or they may be relatively short and heavy. The latter setae usually occur in walking forms. Sexual dimorphism of the legs occurs frequently. Usually the distal segments of the third and fourth pairs of legs of the males are modified for copulation. 3.2 GNATHOSOMA (fig. 59) According to Mitchell (1962) the mouthparts of some water mites are indistinguishable from the terrestrial Trombiculidae and Trombidiidae while in other water mites they appear either more primitive or more advanced than the previously mentioned assemblage. The gnathosoma of water mites is variously referred to as the capitulum, pseudocapitulum or maxillary organ. It is neither a "head", as capitulum indicates, nor an organ, but a distinct body region or tagma, like the idiosoma. The gnathosoma is the anterior trophic-sensory body region housing the chelicerae and bearing the palps. The gnathosoma is articulated with the idiosoma by means of an arthrodial membrane which usually allows a certain degree of movement. 38 It consists of three fused segments, i.e., the precheliceral, the cheliceral segment and the palp segment. The prebuccal groove leads to the pharynx. In all superfamilies, except the Hydrachnoidea, the chel icerae are two-segmented. The chela, or primitive digitus mobilis, may be movable to a certain extent and may range from hook-shaped through sickle-shaped to stylet-shaped. The posterior segment of t he chelicera usually reaches relatively far back into the idiosoma. The palps are usually five-segmented and the segments are numbered from proximal to distal with Roman numerals, i.e., P-I, P-II, P-III, P-IV and P-V. The chaetotaxy and the presence of chitinous projections on the palps are of taxonomic importance. Projections occur most frequently on P-II and P-IV but occasionally on P-I and P-III. Three basic types of palps c·an be distinguished; chelate palps where a dorso-distal projection of P-IV forms a chela with P-V; uncate palps where P-IV is ventro-distally greatly expanded and P-V folds against it; palps which are neither uncate or chelate. 39 4. CLASSIFICATION OF THE HIGHER TAXA OF THE ACARI WITH SPECIAL REFERENCE TO THE CLASSIFICATION OF THE WATER MITES The history of the classification of the higher taxa of the Acari is summarised by Evans et aZ . (1961). Important contributions to the system of classification of the Acari have been made by the following: Kramer (1877), Canestrini (1885), Berlese (1899, 1913), Oudemans (1906a, 1906b, 1923, 1931), Reuter (1909), Vitzthum (1929), Thor (1929), Trag~rdh (1931), Grandjean (1935), Andre (1949), Baker & Wharton (1952), Zachvatkin (1952), Evans et aZ . (1961), Johnston (1965) and Kranz (1971). The many different attempts to construct an acceptable evolutionary classification for the Acari, indicate how di fficult it is to establish and recognise the evolutionary affinities of such an extensive and diversified group of animals. Currently two main schools regarding the higher classification of the Acari exist: Firstly the classification of Baker and Wharton (1952) modified from those by Oudemans (1923) and Andre (1949). They have given the Acari order rank, and this order was divided into f ive suborders, i.e., Onychopalpida, Mesostigmata, Ixodides, Trombidiformes, and Sarcopti- formes. They disregarded the division of the Acari on the basis of the presence or absence of optically active act i no chitin in the core of simple setae as established by-Grandjean (1935) and considered a fundamental division by Evans et aZ . (1961). The second school of classification emphasized the fact that all mit es can be separated into two groups on the basis of the presence or absence of optically active actinochitin. Thi s and other correlat ed characters were incorporated into recent classifications of the Acar i by Zachvatkin (1952), Evans et aZ . (1961) and Johnston (1965). Evans et aZ. raised the Acari to subclass rank and separated them into two superorders Acari-Anactinochaeta {Anactinochitinosi of Grandjean (1935), Parasitiforrnes of Zachvatkin (1952) and Johnston (1965)} and Acari- Actinochaeta {Actinochitinosi of Grandjean (1935), Acariforrnes of 40 Zachvatkin (1952) and Johnston (1965)}. The superorder Acari- Anactinochaeta include the orders Notostigmata, Tetrastigmata, Mesostigmata and Metastigmata while the Acari-Actinochaeta include the orders Cryptostigmata, Astigmata and Prostigmata. The division of the Acari into the actinochaeta and anactinochaeta should be reflected in the classification, and therefore the concept the second school of classification is more acceptable. None of the present groups of mites can be regarded as a link between these two major subdivisions. According to Cunliffe, Baker, Camin, Woolly & Yunker (1958) the differences between these groups, especially in the body structure, are so great, that they should be regarded as super- orders. This view is supported by Zachvatkin (1952) Cunliffe e t al. (1958), Evans et al. (1961) Johnston (1965) Kranz (1971). If the above superorders of the Acari are acceptable, it follows that their innnediate subdivisions should be given ordinal status. Evans et al. (1961) propagated the use of the order name Prostigmata for the group connnonly known as the Trombidiformes. However, Cunliffe (1955) and Cunliffe et al. (1958), at present the authorities on the Trombidi- formes, retain the subordinal rank of this group and use the name Prostigmata for one of the supercohorts of the Trombidiformes. Cunliffe (1955), Cunliffe et al . (1958) recognised three supercohorts under the Trombidiformes, viz., Prostigmata Kramer (1877), Heterostigmata Berlese (1899) and Parasitenini Cunliffe (1955). I agree with Southcott (1961) that the separation of the Prostigmata and the Parasitenini, as suggested by Cunliffe (1955), is not well motivated. Van Huyssteen (1974) also stated that most, if not all of the characters used by Cunliffe (1955), to differentiate between the two supercohorts, are debatable. The super-cohort Parasitenini should therefore disappear. The question now arises whether such a relatively small group as the Heterostigmata should be placed on the same level as the extremely variable Prostigmata. Are the Heterostigmata really so different from the rest of the Trombidiformes? If the diagnostic characters of the Heterostigmata, as defined by Cunliffe (1955), are analysed, the only distinctive character of the group appears to be the structure of the 41 pulvillus. On the basis of this argument the continued recognition of the Heterostigmata does not seem warranted. The only remaining super- cohort, the Prostigmata can then be raised to ordinal rank as Evans et al. (1961) proposed. With the proposed change of the name Trombidi- formes to order Prostigmata the ordinal classification will revert to what it was in 1877. The cohorts, as proposed by Cunliffe, would then be raised to subordinal status recognising the following suborders: Tarsonemini Canestrini and Fanzago (1877); Endeostigmata Grandjean (1937); Promatina Cunliffe (1955); Parasitengona Oudemans (1909). The superfamily and family divisions, except for a few additional water mite families in the Parasitengona, would then remain as proposed by Cunliffe (1955) and Cunliffe et al. (1958). Water mites were probably first accommodated in the classificatory system of other mites by Muller (1781). Until, and even after the classification of Kramer appeared, water mites were variously referred to as Hydrachnae, Hydracarina, Hydrachnids and Hydrachnellae. Kramer (1877) and Berlese (1899) included them in the Prostigmata. Oudemans (1906) included them in the subclass Distigmata. Reuter (1909), Oudemans (1923), K. Viets (1926, 1936, 1956), Baker and Wharton (1952) agreed that they should be classified under the suborder Trombidiformes. The classification system of water mites as constructed over the years mainly by K. Viets and modified by Cook (1974) is an artificial one based on the fact that all these mites occur in fresh water. It serves a useful purpose in the sense that it has brought order into our know- ledge of those mites which occur in fresh water. It does not, however, reflect the phylogeny of these mites and therefore does not satisfy one of the primary aims of a natural classification. It is generally accepted that some of the water mite superfamilies, e.g., Hydrovolzioidea, are closely related to the terrestrial mite superfamilies Calyptostornoidea, Erythraeoidea and Trombidoidea {oudemans (1923), K. Viets (1926, 1931), Vitzthurn (1931), Johnston 42 (1965), Barr (1972>}. For this reason the water mites should be grouped together with their closest terrestrial relatives under the suborder Parasitengona Oudemans (1909) and because of their doubtful intra-relationships the Hydrachnellae Latreille (1805) cannot be given any taxonomic status. The suggestion that the water mites are an ecological group rather than a monophyletic group has been advanced by many authors; Oudemans (1923), K. Viets (1926, 1936, 1956), Mota~ (1928), Vitzthum (1931) Andre and Lamy (1937), Bader (1938, 1954), Baker and Wharton (1952), Mitchell (1956, 1957, 1962, 1964), Woolley (1961) and Cook (1974). Mitchell (1956) suggested that primitive water mites probably had no scleri_tes other than the segments of the appendages and that only the sclerites of the legs may be regarded as homologous throughout the group. At present the classification of the lower taxa is based mainly on sclerotised integumental structures. However, sclerotised plates and shields are easily acquired and/or lost and/or variously fused. According to Mitchell (1956) the exoskeleton of the Acari is not as reliable as that of larger arthropods because the mites could have undergone extensive evolution while still unsclerotised and therefore the exoskeleton may give an incorrect picture of the phylogeny of the group. It can therefore be accepted that the present classification, based on integumental sclerotisation, reflects only recent evolutionary trends up to the family level and that little evidence of phylogenetic lines above family level exists, because of the lack of fossil evidence. The result is that the classification of all mites above the family level is probably artificial and unsatisfactory. Cook (1974) recognised 44 water-mite families. Mitchell (1956) concluded that the large number of families obscures the phylogeny, at least in water mites, but probably in other mites as well. He advocated the consolidation of the families of the Acari and suggested that this may contribute a great deal to our understanding of the phylogeny. Bader (1954) studied the midgut of a number of European genera. He concluded that there were four phylogenetic lines based on the midgut 43 and about 15 based on the exoskeleton. He dit not, however, advance any suggestion as to the rank of these phylogenetic lines. Mitchell (1956) stated that if water mite phylogeny was traced from exoskeletal structures he could recognise "15 to 20 stocks" and that each of these lines is now classified as a family or closely related group of families. He did not suggest a new classification based on the exoskeletal trends. Mitchell (1962) investigated the gnathosoma and came to the conclusion that there are four natural groups into which the various families fall. He pointed out that there may be some parallel lines and that some families do not fit properly into any of the groups. These groups do not coincide with the groups based on the midgut. After a study of the ejaculatory complex of~ large number of genera, Barr (1973) concluded that there is a strong cohesiveness of the genera of water mi tes and that all the families, except the Hydrovolziidae, could be grouped in a single superfamily. Barr's (1972) findings therefore suggest that the members of this superfamily may have a common origin. He pointed out that insufficient information on various aspects of water mites and closely related terrestrial mites prevents the immediate construction of a satisfactory phylogenetic classification. Even a study of the larval stages did not resolve the unsatisfactory state of classification of water mites and Prasad and Cook (1972:3) come to the following conclusion; "Although increased knowledge of the larval stages will doubtless lead to a more natural classification of the Hydracarina, we have resisted the temptation to suggest changes based on the limited number of families, genera and species for which the larvae are adequately known." Even after extensive research on external morphology of virtually all water mite genera (Cook 1974) and the larvae of the majority of water mite families (Prasad and Cook 1972) Cook did not see his way free to make sweeping changes to the existing division on superfamily level. The classification as proposed by Cook (1974) and the changes to the system of K. Viets, are given on pages 44-47. 44 Cook (1974) suggested that the most simple division into superfamilies could be based on a combination of larval and adult characters. These superfamilies would be the Hydrovolzioidea (larvae aerial) Eylaoidea (including all the remaining families with aerial larvae), Hydrachnoidea and the Hygrobatoidea, including all the remaining families (aquatic larvae). Although it is accepted that the water mites evolved from terrestrial parasitengona, it is not clear how often this aquatic invasion has occurred. The above discussion, pointing out various possible phyletic lines, suggests that it may have taken place more than once. This is corroborated by the existence of aquatic, as well as aerial water mite larvae. Aerial larvae probably indicate a later invasion of the aquatic habitat. · The parasitengonid families, Stygothrombiidae and certain Trombidiidae, exhibit varying degrees of adaptation to semi-aquatic or aquatic existence (Cook 1974). This suggests that the invasion of water is probably continuing. It seems therefore, at this stage, inappropriate to attempt drastic classificatory changes at the superfamily level. This can only be done when more about the intra-relationships of water mites and their inter- relationships with the other terrestrial parasitengonid families, based on characters other than integumental sclerotisation, is known. The following classification was suggested by Cook (1974): 1. Superfamily HYDROVOLZIOIDEA (Viets Hydrovolziae) with one family, i.e., Hydrovolziidae. Diagnostic characters The integument is usually thick and lineated, often with close-fitting plates. Glandularia are typically absent, but when present the glandularial seta and the gland are situated on separate platelets. Lateral eyes are usually present but absent in subterranean forms. The gnathosoma terminates in a well developed hypostome and the palps are never uncate or chelate. The gonopore is covered by movable 45 genital plates. Genital acetabula are absent. The ejaculatory complex differs markedly from the type found in other water mites. The larvae are aerial and the urstigmata are absent. 2. Superfamily HYDRACHNOillEA (Viets Hydrachnae) with one family, i.e., Hydrachnidae. Diagnostic characters The integument is pliable and papillate. The lateral eyes are situated on separate platelets. The gnathosoma terminates in a long curved hypostome. The chelicerae are stylet-shaped and single-segmented. The palps are chelate. P-I is the largest segment and P-III is elongated. The genital plates are immovable and the number of acetabula is variable . In the female a protrusible ovipositor is present. The larvae are aquatic. 3. Superfamily EYLAOIDEA (Viets Limnocharae) with three families, i.e., Limnocharidae, Eylaidae and Piersigiidae. This Superfamily excludes the family Protziidae which was lowered in rank to a sub- family and transferred to the Superfamily Hydryphantoidea. Diagnostic characters The integument is most frequently soft and papillated or lined. The lateral eyes are situated on a connnon eye plate. The mouth opening 1s externally situated and surrounded by a membranous fringe. The palps are not uncate or chelate. Genital plates are absent and the acetabula are usually scattered and may be stalked. The larvae are aerial. 4. Superfamily HYDRYPHANTOIDEA (Viets Hydryphantidae) with six families, i.e., Hydryphantidae, Hydrodromidae, Teratothyasidae, Rhynchohydracaridae, Ctenothyasidae and Thermacaridae. The status of the families Clatherosperchonidae, Thyasidae and Neomamersidae have been lowered to subfamily rank and the Neomamersinae has been transferred to the superfamily Hygrobatoidea. The family Pseudo- hydryphantidae has been lowered in rank and transferred from the Hygrobatoidea to the superfamily Hydryphantoidea under the family Hydryphantidae. 46 Diagnostic characters The integument is usually papillate often with embedded platelets. Lateral eyes may or may not be present. The palps may or may not be chelate. The genital acetabula, situated on the movable genital plates may vary from three pairs to many. The larvae are aquatic. 5. Superfamily LEBERTOIDEA (Viets Lebertiae) with seven families, i.e., Sperchonidae, Teutoniidae, Rutipalpidae, Anisitsiellidae, Lebertiidae, Oxidae and Torrenticolidae. The family Pseudohydry- phantidae has been lowered in rank to subfamily status and trans- ferred to the superfamily Hydryphantoidea under the family Hydryphantidae. Cook (1963) reduced the family Mamersopsidae to a subfamily of the Anisitsiellidae. Diagnostic characters The integument varies from soft to heavily sclerotised shields. Lateral eyes may or may not be present. The genital plates are movable and the acetabula usually lie in two parallel rows in the gonopore (in a few isolated groups this is not the case). The palps are never chelate or uncate. The larvae are aquatic. 6. Superfamily HYGROBATOIDEA (Viets Pionae and Axonopsae) with nine families, i.e., Pontarachnidae, Limnesiidae, Omartacaridae, Hygrobatidae, Unionicolidae, Feltriidae, Pionidae, Astacocrotonidae and Aturidae. The families Epallagopodidae, Nautarachnidae, Neotorrenticolidae and the Neomamersidae have been lowered in rank to subfamily status under the family Limnesiidae. It was pointed out that the continued existence of the subfamily Atractidinae is not warranted. This subfamily is now regarded as synonymous with the Hygrobatinae. Diagnostic characters The integument varies from soft or small platelets to heavily sclerotised shields. Lateral eyes may or may not be present. The palps are never 47 chelate or uncate. Genital plates are absent and the varying number of acetabula are situated on acetabular plates. (Acetabula are absent in the marine family Pontarachnidae). The larvae are aquatic. 7. Superfamily ARRENUROIDEA (Viets Mideopsae, Krendowskiae and Arrenurae) with seventeen families, i.e., Mideidae, Momoniidae, Mideopsidae, Uchidastygacaridae, Kantacaridae, Nipponacaridae, Neoacaridae, Bogatiidae, Chappuisididae, Krendowskiidae, Acalyptonotidae, Athienernanniidae, Harpagopalpidae, Hungarohydra- caridae, Arenohydracaridae, Laversiidae and Arrenuridae. Diagnostic characters The integument is usually porous -and heavily sclerotised. Lateral eyes may or may not be present. Movable genital plates are absent and the acetabula are situated on acetabular plates or in the gonopore. The palps are usually uncate or tending towards the uncate condition. The larvae are aquatic. 48 KEY TO THE SUPERFAMILIES OF WATER MITES 1. Larvae aquatic ..............•...•..........• 4 Larvae aerial 2 2. Genital Acetabula absent HYDROVOLZIODEA Genital Acetabula present 3 3. Mouth opening externally surrounded by a membranous fringe EYLAOIDEA Membranous fringe absent ..•...•...•. , ..•.... HYDRYPHANTOIDEA 4. P-I and P-II elongated HYDRACHNOIDEA P-I and P-II not elongated 5 5. Genital plates movable,covering the acetabula which lie in two rows. Acetabular plates absent LE BERTO IDEA Acetabular plates pr_esent, movable genital plates absent .............................. . 6 6. Palp never chelate or uncate HYGROBATOIDEA Palp with a tendency to become uncate ARRENUROIDEA 49 5. KEY TO THE ETHIOPIAN FAMILIES OF WATER MITES (adapted from Cook 1974) 1. Genital acetabula absent (figs. 2, 3, 4) 2 Genital acetabula present (figs. 5, 16, 20, 21) 3 2. Suture lines between third and fourth coxae extending postero-laterally or:_ laterally (fig. 3) HYDROV0LZIIDAE Suture lines between third and fourth coxae extending antero-laterally (fig. 2) P0NTARACHNIDAE 3. Palp chelate, with P-I comparatively long and P-IV shorter than P-III, (fig. 6) chelicera one segmented and lying in the long rostrum; genital field more or less heart shaped, with most acetabula lying anterior to the gonopore (fig. 5) HYDRACHNIDAE Palp either not chelate, or if chelate P-IV is longer than P-III and P-I is shorter than P-II (figs. 12, 13); chelicera two segmented ••••••••••••••••••• 4 4. Mouth opening su·rrounded by a large circular membranous fringe (figs. 8, 10); lateral eyes, if present, incorporated into a median anterior sclerite (fig. 7); palp not chelate; genital acetabula widely scattered and not lying on or surrounded by acetabular plates (fig. 11) 5 Figs. 2-7; fig. 2, Pontarachna capensis Lohman, 1907-venter; fig. 3, HydrovoZzia pZacophora (Monti, 1905)-venter; fig. 4, Pontarachna capensis Lohman, 1907-genital field; fig. 5, Hydrachna rrririjica (Koenike, 1893)- male venter; fig . 6, Hydrachna rrririfica (Koenike, 1893)- male palp; fig. 7 • .. .. EyZais pZanipons Walter, 1924-eye plate. 50 Mouth opening either with only a very small membranous fringe or none; lateral eyes if present, not incorporated into a median anterior sclerite; palps may or may not be chelate 6 5. Eye plate as wide or much wider than long (fig. 7); third and fourth coxae narrowly joined medially on their respective sides (fig. 9) EYLAIDAE Eye plate much longer than wide (fig. 14); third and fourth coxae broadly joined (fig. 11) LIMNOCHARIDAE 6. Palp distinctly chelate, with dorso-distal portion of P-IV extending far beyond insertion of P-V (fig. 13); lateral eyes widely spaced on the respective sides; integumental lenses but no capsules present ••...••.•••.•••••••...• HYDRODROMIDAE Palp either not chelate or, if chelate, dorso- distal portion of P-IV extends only moderately beyond insertion of P-V (fig. 12); lateral eyes variable 7 7. Palp typically chelate (fig. 12) HYDRYPHANTIDAE Palp not chelate; if there is a heavy seta dorsally or medially at distal end of P-IV, I 8 . 10 Figs. 8-14; figs. 8, 10, 'Eylais degener~ta Koenike, 1897-gnathosoma; fig. 9, Eylais crenocula Koenike, 1897-coxae; fig. 11, Limnochares crinita Koenike, 1898-venter; fig • . 12, Hydryphantes incertus Koenike, 1893-palp; fig. 13, Hydrodroma capensis (K. Viets, 1914)-palp; fig. 14, Limnochares tenuiscutata K. Viets, 1914-eye plate. 51 body is not greatly elongated and the acetabula are not stalked 8 8. Genital acetabula located very close to each other in two parallel medial rows (fig. 16, 18, 20, 21) (rarely the posterior acetabula may be shifted laterally); these acetabula typically covered by movable plates (fig. 16); but occasionally the genital plates show varying degrees of reductions 9 Genital field not as described above; if movable genital plates are present, some or all acetabula lie on the plates 13 9. Dorsal and ventral shields present; dorsal shield typically consisting of a large plate and two or four anterior platelets (figs. 15, 17); if only a single dorsal plate is present, an indication that it is a result of fusion of the smaller plates is evident; ventral shield with the median suture line branching into two anterior suture lines extending anteriorly from genital field to tips of first coxae (figs. 16, 58) •.••••.•••••••••••••.••• T0RRENTIC0LIDAE Not with the above combination of characters 10 :·v ·- · \-- d" I 15 16 19 Figs. 15-20; fig. 15, To~renticola (Torrenticola) bicoY'nis n. sp.- male dorsum; fig. 16, Torrenticola (Torrenticola) bicoy,nis n. sp. - female venter; fig. 17, Pseudo- torrenticola fistula n. sp. - female dorsum; fig. 18, Sperchon sp. - female venter; fig. 19, Sperchon Hispidosperchon) biscutatus Lundblad, 1941, female dorsum; fig. 20, Sperchon (Hispidosperchon) biscutatus Lunqblad, 1941 - female .venter. 52 10. All legs inserted far forward on body, actual insertion of fourth legs not visible in ventral or lateral views (fig. 22); ventral sides of P-11 and P-111 without projections or setae (fig. 23) ..............••.•.•....•••...•...•.• OXID.AE Not with the above combination of characters 11 11. Dorsal and ventral shields absent; the anterior suture lines extending anteriorly from genital field to tips of first coxae (fig. 24); suture line between second and third coxae present anteriorly and pos_terior- ly but obliterated in middle (fig. 24); palp of a characteristic shape with a long disto- ventral seta on P-11 and five to seven long setae on medial surface of P-111 (fig. 25) LEBERTIIDAE Not with the above combination of characters 12 12. Fourth legs with well developed claws; lateral eyes in capsules (fig. 19); a solid ventral shield never present (figs. 18, 20); third pair of acetabula usually not oriented at right angles to other two pairs; if third pair oriented somewhat at right angles to other two pairs, the third pair not as elongated as other pairs (fig. 21) SPERCH0NIDAE 53 Fourth legs typically without claws (fig. 26) and lateral eyes typically not in capsules ANISITSIELLIDAE 13. Dorsum and venter with numerous reticulate platelets which surround the glandularia (fig. 27); ventral side of P-II with two or three heavy setae TERATOTHYASIDAE Not with above combination of characters 14 14. P-II with a single hair-like or peg-like seta on ventral side (fig. 29), this seta either sessile or located on a tubercle of variable length; palps not uncate; claws usually absent from fourth leg (fig. 30); dorsal and ventral shields rarely present (fig. 28) ..•................. LIMNESIIDAE P-II without a single hair-like or peg- like seta on the ventral side (do not confuse setae ventral projections); rarely more than one seta may be present on the ventral side of P-II 15 15. 1-Leg-6 much shorter than 1-Leg-5; claws of first leg enlarged and able to fold dorso-proximally against a dorsal projection of 1-Leg-6 to form a grasping organ (fig. 34) MOMONIIDAE 21 23 25 26 Figs. 21-27; fig. 21, Sper chon sp.-genital •field; fig. 22, Oxus stuhlma:ni (Koenike, 1895)-idiosoma; fig. 23, Oxus stuh lma:ni (Koenike, 1895)-palp; fig. 24, Leber tia capen~is K. Viets, 1956-venter; fig. 25, · Lebertia capensis K. Viets, 1956-palp; fig. 26, Platymamersopsis cooki K.O. Viets, 1970-IV-Leg-5, 6·, Fig. 26, Teratothyasides sp.-dorsum. 54 1-Leg-5 and 6 various, but not as described 16 16. Cheliceral chela serrate-dentri- culate (fig. 31); in addition to the genital acetabula in the gonopore region there are numerous acetabula lying free on the ventral shield which extend far antero- laterally (fig. 32) but these are extremely difficult to see because they are not on acetabular plates and superficially resemble Pody pores HAR.PAGOPALPIDAE Genital acetabula usually confined either to gonopore or to acetabular plates flanking the gonopore; in a few instances acetabula are present in both gonopore and on the ventral shield, but on the latter do not extend far antero-laterally and are on recognisable acetabular plates 17 17. All genital acetabula confined to the genital field; well developed condyles associated with openings (points of insertion) of fourth legs (fig. 35); a pair of glandularia appearing to be incorporated into the medial margins of the fourth coxae; these glandularia usually close to suture line between third and fourth coxae but may be more posterior in position in some species (fig. 34) KRENDOWSKIIDAE 2.9 Figs. 28-34; fig. 28, Limnesia sp.-venter; fig. 29, Limnesia sp. palp; fig. 30, Limnesia sp-IV-Leg-5,6; fig. 31, Ha:rpagopalpus octoporus K. Viets, 1924-chelicera; . fig. 32, Ha:rpagopalpus octoporus K. Viets; 1924- coxae and genital field; fig. 33, Ha:rpagopalpus Octoporus K. Viets, 1924-palp; fig. 34, Momonieiia africana Cook, 1966-I-Leg-4,5,6 of male. 55 Not with the above combination of characters 18 18. Seven or fewer pairs -0f genital acetabula present and these confined to a single row on each side of the gonopore. The rows may meet each other or may almost meet each other medially or may be widely separated (fig. 39) •• MIDE0PSIDAE Not as described and illustrated above 19 19. Palp not uncate (fig. 41) 20 Palp uncate (figs. 52, 53) 27 20. Body laterally compressed and noticeably higher than wide (fig. 37); dorsum with a narrow median strip of soft integument which may contain small sclerites (fig. 36) ......•.......•.... ATURIDAE (FR0NTIP0D0PSINAE, Karlvietsia) Body not laterally compressed; if body is heavily sclerotised, there is not a narrow, median unsclerotised strip as illustrated above ................................................... 21 21. Fourth coxae bearing a pair of glandularia 22 Fourth coxae lacking glandularia ....................... 23 Figs. 35~40; Allokrendowskia dentipes continentalis K.o. ·viets, 1962-venter; fig. 36, Karlvietsia angustipalpis K.O. Viets, 1962-female dorsum; fig. 37, Karlvietsia angustipalpis K.O. Viets, 1962-female venter; fig. 38, Africacarus strenzkei K.O. Viets, 1962-male gnathosoma; fig. 39, Mideopsis sp. -female venter; fig. 40, Hygrobates sp. - male venter. 56 22 . Usually soft bodied (fig. 40); if dorsal and ventral shields are present there is usually a down-turned seta at distal end of 1-Leg-5 or if dorsal and ventral shields are present (males only) P-V (fig. 41) is long, curved and pointed (Hygrobatopsis) or if dorsal and ventral shields are present (males only) the gnathosoma (fig. 38) is long and curved (A fricacarus) ... . ....•..•......... . ..... .. ... HYGR0BATIDAE Dqrsal and ventral shields present and not as the alternatives mentioned above (figs. 42, 43) ATURIDAE (in part) 23 . Dorsal and ventral shields present 26 Soft bodied or with scattered sclerites, but distinct dorsal and ventral shields are absent 24 24 . Genital acetabula numerous (more than 10 pairs) and either IV-Leg-4 concave on one side and contains numerous peg-like setae (fig . 47) or median surface of P-IV with a peg-like seta at distal end and there are no well developed projections associated with insertions of fourth legs (figs. 44, 45) PI0NIDAE (in part) . _:;,:.,.:.'·:::·.') ~I -W¥i~i, 1;!1itf0 > \\S.t '0" ::. /1/ <;l 019 / G - 44 45 Figs. 41-48; fig. 41, Hygrobatopsis l evipalpis K. Viets 1924- palp; fig. 42, Axonopsis sp. - female venter; fig. 43, Axonopsis sp. ,- female dorsum; fig. 44, Piona damasi Lundblad, 1949 male venter; fig. 45, Piona damasi Lundblad, 1949 - female venter; fig. 46, Pollicipalpus scutatus K. Viets, 1924 - male venter; fig. 47, Piona damasi Lundblad, 1949 - male IV-Leg-4; fig. 48, Pollicipalpus projectus Walter, 1935 - male palp. 57 Not with the above combination of characters 25 25. Openings for insertion of fourth legs either with large associated projections which extend laterally or only slightly postero-laterally or, if projections extend decidedly postero- laterally (fig. 46), P-IV with distal project- ions as shown in fig. 48 (mites belonging to this second category are known only from West Africa) UNIONICOLIDAE (in part) Openings for insertion of fourth legs either with small or no associated projections£!_, if large projections are present, they are directed posteriorly or decidedly postero- laterally and the palp is not as illustrated (fig. 48) ATURIDAE (in part) 26. Ambulacral claws simple (fig. 50) or with clawlets; posterior margins of fourth coxae more or less truncate or rounded (fig. 49); chelicerae fused with each other medially or separate; peg-like seta of P-IV, if present, variable in position, but often ventral or dis to-ventral UNIONICOLIDAE (in part) 52 Figs. 49-56; fig. 49, Neumania megalopsis K. Viets, 1913 - venter; fig. 50, Neumania sp. ambulacrum; fig. 51, Fiona acwrrinata Walter & Bader, _1952 - male III-Leg-5,6; fig. 52, Arre~urus forcipetiolatus Walter, 1922 - female palp; fig. 53, Arrenurus bowmakeri van Rensburg, 1974 - male palp; fig. 54, Arrenurus bowmakeri van Rensburg, 1974 - male venter; fig. 55, Arrenurus bowmakeri van Rensburg, 1974 female venter; fig. 56, Africasia radiata Cook, 1966 - male venter. 58 Ambulacral claws with clawlets (fig. 51); posterior margins of fourth coxae !Ik)re or less angled (figs. 44, 45); peg-like seta of P-IV, if present, disto-ventral or distal in position PIONIDAE (in part - most species) 27. No acetabula present in the male gonopore; genital acetabula usually extending well laterally on distinct acetabular ridges (figs. 54, 55, 56) in both sexes (exception: females of Africasia) ARRENURIDAE p A R T Ill 59 6. FAMILY TORRENTICOLIDAE Piersig, 1902 TorTenticolidae Piersig, 1902 Paper 53:849; 0udemans 1941:178 K. Viets 1949:296, 311; Cook 1974:144. Atractideidae Thor 1902:408; K. Viets 1936:232. Atractididae K. Viets 19261:192, 197; Lundblad 1927:408, 410, 411. Atracticidae and Atractidae Wesenberg-Lund 1939:579, 594. Diagnostic characters The idiosoma of the representatives of this_ family is dorso-ventrally flattened, round to oval in shape and heavily sclerotised. In Torrenticola sucira Cook, 1967 the idiosoma is elongated. Dorsally it is covered with a heavily sclerotised dorsal shield and a number of peripheral platelets may be present. Ventrally the coxal plates are fused to form a single ventral shield. The dorsal and ventral shields are connected by a lightly chitinised striated membrane. This membrane lines a groove which runs along the posterior and lateral periphery of the idiosoma. The gnathosoma is anteriorly attached to the idiosoma and it fits into a socket, the camerostome, formed by the anterior coxae. The palps are dorsally attached to the gnathosoma. Dorsum (fig. 57) The dorsum is covered by a large dorsal shield and a variable number of peripheral platelets. The shield may be ornamented or smooth and the periphery may be thickened, in which case it would be seen as a very distinct border. In older specimens two distinct areas can be distin- guished on the dorsal shield. The first is the large, heavily sclerotised area and the second is the postero-lateral border area, which appears to be less heavily sclerotised and is marked with finer or coarser striations. This · is the area of secondary sclerotisation. PLATE I a. Torrenticola (Torrenticola ) bicornis n. sp. venter. b. 'J1orrenticola (Torrenticola ) bicornis n. sp. dorsum. c. Pseudotorrenticola fistula n. sp. venter. d. Pseudotorrenticola fistula n. sp. dorsum. e. Torrenticola (Torrenticola ) eurys toma K. Viets, 1956 venter LU 3 a.. ANTERIOR PLATELET GLANDULARIUM (APG) ANTERIOR PLATELET POSTERIOR PLATELET SETA (PPS) POSTERIOR PLATELET POSTERIOR PLATELET GLAN DULAR_IUM ( PPG) --~- DORSAL SHIELD ~ ;: 1r---,,------1-- MUSCLE ATTACHf~ENT DORSAL GL AND ULARIUM (DG1) h :~ @ MARKS LI NEATE D AREA 57 /ENTRAL GLANDULARIUM {VG ) GNATHOSOMAL BAY 1 ANTERIOR SUTURE ... -- ., ,,.. -... -....... , ... , ...... 1. • 1~--~~MEDIAN SUTURE ~r--____'.!:.,4i -- LATERAL SUTURE. i'l -. +--.\-l-~----jr,r ACETABULUM (VG 4) -+.ll+----r., ,1~ - ---Hr,+-- GENITAL PLATE VENTRAL SHIELD .....__,.-ti'::-:", OSTERIOR SUTURE INEATED AREA (V l ~- ANAL PORE 58 ' Figs. 57-58; fig. 57, A generalised Torrenticola-dorsum. fig. 58, A generalised Torrenticola-venter. 60 The anterior margin of the dorsal shield is usually wedged in under- neath the platelets and in the centre, situated on either side of the midline is a pair of integumental marks. These marks are points of muscle attachment. Three pairs of glandularia (DG , DG and DG ), each 1 2 3 associated with a seta open on the dorsum. These setae originate close to the glandularial openings and may be simple and slender, bifurcate or double bifurcate. DG is always situated on the heavily sclerotised 1 area but varies considerably in position - from immediately lateral to the muscle attachment marks to the periphery of this heavily sclerotised area. DG is situated postero-laterally and DG posteriorly on the 2 3 dorsum. Both DG and DG may be situated either on the heavily 2 3 sclerotised area or on the lineated border area of secondary scleroti- sation or on separate platelets. Apart from the large dorsal shield the dorsum is also furnished with a variable number of dorsal platelets. The most common arrangement is two pairs of anterior dorsal platelets which, especially the posterior pair, may exhibit various degrees of fusion with the dorsal shield or with the anterior pair of platelets. In the subfamily Testudacarinae there are three fairly large anterior platelets and seven pairs of lateral and posterior platelets. Venter (fig. 58) The entire venter is covered by the ventral shield, which is formed by the fused coxae, (German-epimeren, Cook 1966_, coxae) which completely surround the genital field. Coxae II and III are completely fused. In T. (Allotorrenticola) suvarna Cook, 1967, however, a lateral line of fusion between coxae II and III is visible. Medially the line of fusion between the right and left second and third pairs of coxae is clearly visible. The term ''median suture'' is proposed for this suture. The length of the median suture is extremely variable and it is usually longer in males than in females. Amongst different species it may vary from being virtually non-existent, to reaching up to the points of attachment of the third or even second pair of legs. The lines of fusion between the first and second pairs of coxae originate at the anterior end of the median suture, which bifurcates to form the two anterior sutures. Coxae III and IV are always separated by sutures reaching obliquely anterior from the anterior angle of the genital PLATE II a. TorrenticoZa sp. excretory pore, VG7 and postero-lateral lineated area. b. PseudotorrenticoZa fistula n. sp. VG6 and postero-lateral lineated area. c. TorrenticoZa sp. postero-lateral lineated area of dorsum. d. TorrenticoZa (TorrenticoZa ) bicornis n. sp. postero-lateral lineated area. e. Torr enticoZa (TorrenticoZa) eurys toma K. Viets, 1956 postero-lateral lineated area. PLATE II 61 field to just posterior to the point of attachment of the third pair of legs, where they curve antero-medially and proceed dorsally. The posterior margins of the fourth pair of coxae are demarcated by the incompl~te curved posterior sutures. These sutures originate, like the others, from the periphery of the genital field and proceed postero- laterally into the venter. The posterior sutures exhibit a great degree of variation. In some forms they may almost be absent while in others they are prominent. The direction of the posterior sutures is also variable. In some species they may run almost transversely while in others they may be directed almost posteriorly and curving slightly · laterally and distally. The posterior sutures exhibit a degree of sexual dimorphism in that they are usually more curved and more posteriorly directed in females than in males. The anterior coxae form the ventral prolongation of the podosoma beyond the idiosoma. This prolongation is laterally extended and forms a coxal ledge onto which the first three pairs of legs are dorsally attached. It also forms the lateral walls and the roof of the camero- stome. The first pair of coxae form the ventral and the inner lateral walls of the camerostome. The fourth pair of coxae are delimited by the lateral and posterior sutures. The area enclosed by the posterior sutures, the genital field and the excretory pore was probably formed by fusion of some posterior ventral platelets. Seven pa.irs of glandularial openings occur on the venter as a whole. These glandular- ial openings are designated from anterior to posterior by the symbols VG - VG 7 . All these glandularial openings have an associated seta 1 which may be simple, bifurcate or double bifurcate. VG - VG are 1 4 always situated on the heavily sclerotised area, while VG , VG 5 and VG 6 7 may be situated either on the heavily sclerotised area or on the striated border area. VG VG7 , however, are mostly situated on 5 the striated border area. The excretory pore is always in the striated area. The venter as a whole may be furnished with as many as 28 pairs of ventral setae (including the setae associated with the openings of the glandularia). Three pairs of ventral setae are designated by special symbols because of their constant and determinable positions. s1 (fig. 58) PLATE III Torrenticola (Torrenticola ) trochlearis n. sp. a. VG6 with associated branched seta b. Postero-lateral lineated area with VG6, VGand excretory pore 7 c. VG7 and excretory pore d. VG7 with double branched seta. PLATE Ill 62 situated at about the antero-lateral angle of the lateral suture; s 2 situated close to the genital field just lateral of the median suture and s situated in the area between the posterior sutures (fig. 58). 3 The genital field is completely encircled by the fused coxae and its shape may range from oval to almost rectangular. In most cases however, the anterior lateral angles are more or less angular and the posterior lateral ones more or less rounded. The genital orifice is guarded by the two movable genital plates. The outer margins of these plates are variously sclerotised. A varying number of minute setae are situated on the periphery of each plate. Medially there are six pairs of acetabula, arranged in two parallel rows. In the sub- family Testudacarinae are only three pairs of acetabula. Gnathosoma (fig. 59) In Torrenticola the retractable gnathosoma fits into the camerostome formed by the anterior coxae. According to Evans et al. (1961) the gnathosoma is composed of three segments, i.e., the precheliceral segment, the cheliceral segment and the palp segment. Ventrally the palp coxae, the palp endites and the deutosternum fuse to form the hypognathum. The latter is elongated anteriad to form the hypostome wherein the cheliceral groove is situated. The lateral walls of the hypostome are dorsally closely applied but not fused to each other (plate VIa). The cheliceral membrane protrudes through this dorsal slit. The tip of the hypostome is furnished with two pairs of setae both situated in circular depressions (plate VI). The depressions in which the posterior pair of setae is situated, are deeper than the anterior depressions (plate VIe). Internally the tip of the gnathosoma is furnished with a cluster of veriform structures (plate VI, b, c, f) which represent the malae. Anteriorly the two segmented chelicerae lie in a groove, the cheliceral groove reaching from the tip of the hypostome to the palp bases. Posterior to the palp bases the chelicerae lie in a tube, the gnathothecum. The first segments of the chelicerae, the movable chelae, are situated anteriorly in the cheliceral groove and the posterior segments reach through the gnathothecum into the idiosoma. The chelae PLATE IV a. Torrenticola (Torrenticola ) trochlearis n. sp. porous integumental concavities. b. Torrenticola sp. - ambulacrum. c. Torrenticola (Torrenticola) trochlearis n. sp. genital plates of male. d. Torrenticola (Torrenticola) bicornis n. sp. gen i tal plates female. e. Pseudotorrenticola fistula n. sp. genital plates of female. PLATE IV ) C bi ~ a >}----- - .....,. k. Fig. 59; Internal structure of t he gnathosorna of Torrenticola 63 are not attached to each other but irrnnediately posterior to the chelae the chelicerae are closely applied with median interlocking surfaces (figs. 59 b - e ). Posteriorly they become separated , flattened and more heavily sclerotised (figs. 59 j, k) . The chelicerae reach well into the idiosoma and their muscles are posteriorly attached. In the coxal region the chelicerae are supported by a trough-like chitinous element, the subcheliceral apodeme, (sigmoid piece, Mitchell 1962) which is posteriorly wide and anteriorly tapering to a spine. Anteriorly in the hypostome the gnathosomal cavity consists of two canals latero-ventral to the cheliceral groove (fig. 59 b). These two canals course posteriorly and fuse to form a U-shaped gnathosomal tube (fig. 59 c, d), which widens to form the gnathosomal cavity (fig. 59 e-j) which is posteriorly continuous with the idiosomal cavity . The proximal palp muscles are housed in the gnathosomal cavity . The prebuccal groove arises fro m the cheliceral groove anteriorly 10 the hypos tome ( fig . 59c) and ex t ends posteriorly for a short distance 10 the floor of the cheliceral groove (fig. 59c) and further posteriorly it becomes a closed pre bu cc al tube lying between th e cheliceral groove and the gnathosomal tube (fig. 59d). It then passes through the roof of the gnathos omal cavity (fig. 59 e) and posteriorly becomes attached to the floor of the gnathosomal cavity (fig. 59 g-k). The prebuccal tube extends to the posterior end of the gnathosoma wher e the actual mouth opening is situated. The palps are extremely variable. They are usually five-segmented except in the subfamily Neoatractidinae wher e they are four-segmented. Two types of palps occur; relatively long and slender palps with P-V not tapering; (fig . 78) and relatively short, compact with P-V tapering (fig. 90). The long and slender palps may exhibit different var iations. They may be long and slender without any ventral projections (figs. 95, 99) or P- II and P-III may carry scoop- like ventro-distal projections with serrated edges (fig. 79, plate Ve, d) or blunt-ending, knob-like ventro-distal projections in which case the projections are covered with denticles (figs. 62, 83, plate VII a, b, c , e) . The projections may consist of ventral serrated cristae . PLATE V Torrenticola sp. a. P-II, P-III, P-IV-projections. b. Lateral view of the palp and the hypostome. c. P-II projection. d. P-III projection. e. P-IV tubercles. f. P-V with claws. PLATE V PLATE VI Torrenticola sp. a - f. Hypostome of the gnathosoma. PLATE VI 64 P-IV carries one to four tubercles and a number of associated setae (figs. 76, 79, 88, plate Ve). P-V is usually short and not tapering. In the compact type of palp the segments are all shorter than in the pr evious type except for P-V which is longer and tapering (figs. 103, 106). P-II and P-III usually carry a relatively heavy ventro-distal seta (fig. 103). Both types of palps P-V end in four curved, movable claws (plat e Vf). Sexual dimorphism of the palps has only been reported for the monotypic subgenus, Allotorrenlico la , where distinct ventral projections are present in the male but absent in the female. Legs (figs. 68 - 71, 111 - 114) The legs increase in length from anterior to posterior. Apart from ordinary slender setae the legs are furnished with heavy setae with serrated edges. These heavy setae occur in increasing numbers on legs 1, 2 and 3 but fewer are present on leg 4 than on leg 3. The l egs are six-segmented consisting of the I-Leg-1 (coxa), I-Leg-2 (trochanter), I-Leg-3 (femur), I-Leg-4 (genu), I-Leg-5 (tibia) and I-Leg-6 (tarsus). The tarsus terminates in the ambulacrum, which consists of two bifurcated claws. The claws can be folded back into a dorsal depression of the tarsus. The tarsus is furnished with numerous very fine distal setae. Discussion Because of the involved synonomy of the genus 'J'orrenticola Piersig, 1896 (seep. 70), it was regarded as one of the genera of the family Hygrobatidae Koch, 1842. Piersig (1902) created the family Torrenticoli- dae to accommodate Torrentico la anomala (Koch, 1837) but hydrachnologists incorrectly gave priority to the family names Atractideidae (Thor, 1902) and Atractididae (Viets, 1926). 0udemans (1941) pointed out that the family name Torrenticolidae should be given priority but it was only after K. Viets (1949) dealt with th e synonomy of Atractides (Koch, 1837) and 'l'orr•entico la Piersig, 1896 that the correct usage of the family name Torrenticolidae was constantly adopted by workers in this field. PLATE VII a. Torrenticola (Torrenticola) trochlearis n. sp. P-III projection. b. Torrenticola (Torrenticola) trochlearis n. sp. P-II projection. c. Torrenticola sp. - P-III projection. d. Torrenticola (Torrenticola) bicornis n. sp. gnathosoma. e. Torrenticola (Torrenticola) bicornis n. sp. P-II projection. f. Torrenticola (Torrenticola) bicornis n. sp. P-III projection. PLATE VII 65 KEY TO THE SUBFAMILIES OF THE TORRENTICOLIDAE I. Three pairs of genital acetabula; dorsal shield surrounded by numerous peripheral platelets. VG absent . 4 Subfamily TESTUDACARINAE Six pairs of genital acetabula; VG 4 present. dorsum with four or fewer anterior platelets 2 2. Palp four segmented Subfamily NEOATRACTIDINAE Palp five segmented Subfamily TORRENTICOLINAE 66 6 . I SUBFAMILY TESTUDACARINAE Cook, 1974. Testudacarinae Cook 1974: 145 This subfamily was erected by Cook (1974) to accommodate the Genus Testudaca:t'us . Walter, 1928. Diagnostic characters The most distinguishing feature of the representatives of this sub- family is the presence of a single median anterior platelet with many small platelets completely surrounding the large dorsal shield; the presence of 6 pairs of glandularia on the dorsum and only three pairs of genital acetabula. The suture lines between the third and the fourth coxae are laterally and medially developed. There are no glandularial openings on the third and fourth coxae - VG2 and VG4 absent. A ridge extends anterior and postero-medially from the insertions of the fourth pair of legs. The posterior suture is therefore prominent. VG is situated close to 6 the posterior suture and consequently always on the heavily sclerotised area. VG , VG and the excretory pore may or may not be situated on 5 7 the heavily sclerotised area. The position for the insertion of the fourth pair of the legs is furnished with ventral condyles. Genus Te s tudacarus Walter, 1928 Type species Testudacarus tripe ltatus Walter, 1928 Diagnostic characters Only genus with the characters of the subfamily. 67 6.2 SUBFAMILY NEOATRACTIDINAE Lundblad, 1941 Neoal~aelidinae Lundblad, 194lb:364; 1953:472; Cook 1974:146 Diagnostic characters The dorsum is covered with a large dorsal shield and two small ante rior platelets. The venter exhibits the typical torrenticolid features. A pair of glandularia opens on the third pair of coxae. Six pairs of genital acetabula are present. The ejaculatory complex of the male is protrusible. The gnathosoma exhibits the most characteristic features. The palps are four-segmented and the terminal segments are greatly reduced in size. The gnathosoma is relatively long and it is terminally furnished with setae. Genus Neoatractides Lundblad, 1941 Type species Neoatractides inachus Lundblad, 1941 Diagnostic characters Only genus with the characters of the subfamily. 68 6.3 SUBFAMILY TORRENTICOLINAE Piersig, 1902 Torr enticolinae Piersig 1902:849; Monti 1910:52; 0udemans 1941:178; K. Viets 1949:296, 311; Cook 1974:147 Atractidinae Koenike 1909:78; 1910:149 K. Viets 1936:232 Alractideinae Thor 1911:384; Thor 1913:47 Diagnostic characters The dorsum is typically covered with a large dorsal shield and two pairs of smaller anterior platelets. The posterior pair of platelets may be variously fused with the anterior platelets and the dorsal shield. The anterior platelets are furnished with a pair of lateral glandularia, the anterior platelet glandularium (APG) while the posterior pair of platelets carry an anterior pair of setae, the posterior platelet seta (PPS) and a posterior pair of glandularia, posterior platelet glandularium (PPG). The venter is covered by the ventral shield formed by the fused coxae. The suture lines between the second and third coxae are medially obliterated. There are always six pairs of genital acetabula and the ejaculatory complex may or may not be protrusible. The gnathosoma may be relatively short or elongated as in Pseudotorrenti- cola . The hook-shaped or sickle-shaped chelicerae are housed in the gnathosoma. The palps, attached to the gnathosoma, are five-segmented. In T. cristata (K. Viets 1916) the terminal segment is extremely short and the terminal setae appear to arise from P-IV. P-II, P-III and P-IV may be variously furnished with tubercles. In some species the palps are completely devoid of any tubercles or projections . 69 KEY TO THE GENERA OF THE TORRENTICOLINAE Gnathosoma long and tube-like; chel i cerae housed entirely in the gnathosoma Genus Pseudotorrenticola Walter, 1906 Gnathosoma not tube-like; posterior cheliceral segment protrudes i nto the idiosoma Genus Torrenticola (Koch, 1837) 70 6.3. 1 Genus Torrent i cola (Koch, 1837) Torrenticola (Piersig 1896a:438; Koenike 1898:378; Piersig 1900, paper 4:562; Wolcott 1905:196, 223; Oudemans 1941:178; K. Viets 1949:296; Angelier 1954:100; Besseling 1954:247; Lundblad 1957:147. At r actides Koch 1837:10; Thor 1899b:29, 38; Koenike 1908:258; K. Viets 1916:259, 396; 1936:233; Lundblad 1941b:31; Halbert 1944:71; Szalay 1947:289. Ruse tria Thor 1897:20 Diagnostic characters Characters of the subfamily. The anterior coxae do not form a long tube-like camerostome. The gnathosoma is relatively short and not greatly elongated to form a tube. Type species Torrenticola (Torrenticola) anomala (Koch, 1837) Discussion C.L. Koch (1837) described, amongst others, three species of the genus Atractides (Koch 1836-41), i.e., A. anomalus, A. spinipes and A. se tiger without giving the diagnosis for the genus or determining a type specimen. Only in 1842 (p. 22) did he name spinipes (Koch 1842, table II, 10) as the type (p. 6). The species A. spinipes is therefore inseparably linked to the generic name Atractides. Koch did not, however, recognise that the other two species, i.e., anomalus and s etiger belong to different genera. (See the synonomy of Atractides C.L. Koch 1837, p. 121). A. anomalus is the species concerned with the question of the synonomy of the genus Torr enticola. 71 Atractides anomalus Koch 1837, one of the species incorrectly assigned to the genus Atractides, was not mentioned in the literature until Piersig (1896) noted that anomalus differed markedly from A. spinipes Koch, 1837 and he created the new genus Torrenticola. He did not, however, give an adequate survey of the diagnostic characters of the new genus. His creation of the new genus with anomalus as type proved to be perfectly valid. This was supported by Koenike (1898) when he described the species Torrenticola microstoma from Tanzania, and formulated the diagnostic characters of the genus Torrenticola. Without any apparent reason, Koenike (1908) reverted to the use of the genus name Atractides for the species amplexus, convexus and maglioi which are Torrenticola species sensu Piersig. This conception was followed by Koenike in his later works (1909, 1910) and almost all other hydrachnologists. Thor (1897, p. 20-22) described the second Torrenticola species under the name Rusetria spinirostris (T. microstoma Koenike (1898) was the third but he did not compare it with T. anomalus). Thor (1899b) assigned both Torrenticola Piersig (1896a) and Rusetria Thor (1897) as synonyms of Atractides Koch, 1837. This was undoubtedly incorrect because Koch (1842) had already designated sp~nn~pes and not anomalus as the type of Atractides. Wolcott (1905) put the record straight by reaffirming anomalus (Koch 1837) as type to the genus Torrenticola Piersig (1896a). Although the question of the synonomy between Torrenticola and Atractides had thus been resolved, hydrachnologists continued to use Atractides for what should have been Torrenticola. K. Viets (1949) suggests that there must have been" ••• oftmals scharfen Polemiken und Animositaten •••• " between Koenike and Piersig and this might have been the reason why Koenike reverted to the use of Atractides instead of Torrenticola. Piersig died in 1906 and Koenike persisted in his incorrect use of Atractides and he was followed by other hydrachnolo- gists. 72 Only after K. Viets (1949) published his interpretation on the synonomy of Torrenticola and At r actides did Torrenticola sensu Piersig come correctly into use. The subgeneric division of the genus Torrenticola has undergone numerous changes since the original description of Tor•renticola (Torrenticola) anomala (Koch, 1837). The subgenus Torrentico l a is based on Torrentico l a anomala (Koch, 1837). In T. anomala all the anterior platelets are free and this was regarded as the distinguishing character of the subgenus Torrent icola . Thor (1897) described Rusetria spinir os t ris . It transpired that Rusetria was actually synonomous with Torrentico l a (originally Atractides ). In Rusetr ia the posterior platelets were fused with the dorsal shield and on this basis Rusetria became the second subgenus. The third subgenus, Monatractides was created by K. Viets (1926) with Torrentico l a uniscutata (K. Viets, 1925) as type. The fusion of all the platelets with the dorsal shield was used as the distinguishing character. The subgenus Rusetrie l la was created by K. Viets (1931) with Torrenticola acutiscutata (K. Viets, 1913) (originally Atractides uni scutatus) as type. In this subgenus the anterior platelets on each side are fused to form a single platelet. Halbert (1944) created the fifth subgenus, i.e., Megapalpi s with Torrenticola t enuiros tris (K. Viets 1936) (originally Atractides tenuirostris) as type. As subgeneric characters he used the absence of ventral projections from P-II and P-III and the size of the palps (large). He did not mention the condition of the dorsal platelets in his sub- generic circumscription. In the same article he (Halbert 1944) described the sixth Torrenticola - subgenus, i.e., Micropa lpi s with Torr enticola s tadler i (Walter, 1924) as type. Without consider i ng the dorsum he used only the size of the 73 palps (short) and the absence of tubercles or spines on P-II and P-III as subgeneric characters. K. Viets (1956) proposed a change of the name Micropalpis to Micropalpiger because of pre-occupati on. Szalay (1947) created the subgenus Brevatractides which he characterised as follows: the gnathosoma has a very short hypostome and long postero- dorsal processes; the palps are short and stout without any projecttons or spines on the flexor side and all the dorsal platelets are free. Angelier (1954) recognised six of the above mentioned subgenera and he regards Brevatractides Szalay, 1947 as synonomous with Megapalpis Halbert, 1944. He adds, however, that Halbert did not mention one of the di s tin- guishing characters of T. t hori , i.e., the stylet-like curved chelae of the chelicerae. Angelier also mentions that the dorsum is covered by five separate elements. Lundblad (1927, 1957) suggested that the subgeneric division of Torrenticola should not be based on the state of fusion of the dorsum elements but rather on the structure of the gnathosoma. He divided the genus into two subgenera (Torr ent i co l a and Monatracti des) on the basis of the length of the postero-dorsal gnathosomal processes. Cook (1966) pointed out that fusion of dorsal platelets has taken place independently in different species-groups within the genus. Consequently members of the same species group were placed into separate subgenera while other much more distantly related species were lumped into the same subgenus. He then, like Lundblad, divided the genus Torrenticola into the subgenera Torrenticola and Monatr actides on the basis of the structure of the palps. In Torrenticola (Torrenticola ) P-V is very short and t apering very little towards the distal end; P-II and P-III, usually with various types of ventral projections, and setae are either absent from the ventral side, or if present they are not thickened. In Monatractides P-V is relatively long and tapering towards the distal end, P-II and P-III are usually without well defined ventral projections and the ventral setae on P-II and P-III are usually thickened. 74 Cook (1974) supplemented his (1966) subgeneric characters with those which Lundblad used, i.e., the short postero-dorsal gnathosomal processes in Torrenticola (Torrenticola) and the long ones in Monatractides . A number of species, i.e., T. andrei (Angelier, 1950), T. fagei (Angelier, 1949) T. tenuirostris (K. Viets, 1936) T. thori (Halbert, 1949), T. pugnionirostris (K. Viets, 1939), T. rhamphus (Lundblad, 1941a) and a new species from Southern Africa, exhibit a constant variation of a mixture of the characters of the above mentioned subgenera. As in Torrenticola (Torrenticola ) the palps are relatively long with P-V not tapering distally and the gnathosomal postero-dorsal processes are short and the hypostome is long. As in Monatractides , P-II and P-III are completely devoid of ventral tubercles or spines. Furthermore the chelicerae are always distally distinctly sickle shaped. These characters were pointed out by Halbert (1944) and Angelier (1954) as characteristic for the subgenus Megapalpis. Lundblad (1957) stated that it is unjustified to maintain the subgenus on the basis of the stylet- or sickle-shaped chelae. However, only those species with sickle- shaped chelae have relatively long palps which lack ventral projections on P-II and P-III. The constant occurrence of the combination of these characters justifies the reinstatement of the subgenus Megapalpis Halbert, 1944. Lundblad (1941a) described the genus Heteratractides . Cook (1974) lowered the status to subgeneric level because it differs from other Torr enticola species mainly because the hypostome is somewhat f lattened and slightly broader than the rest of the gnathosoma. Cook (1967) described the subgenus Allotorrenticola . This subgenus is characterised by the distinct sexual dimorphism of the palp and the pair of glandularia occurring on the third pair of coxae. The present author therefore recognises the following subgenera of the 75 genus Torrenticola = Torrenticola Koch, 1837 Type species Torrenticola (Torrenticola) anoma la (Koch, 1837) Monatractides Viets, 1926 Type species Torrenticola (Monatr actides) unisautata (K. Viets, 1925) Heteratractides Lundblad, 1941 Type species Torrenticola (Heter atractides) serratir ostris (Lundblad, 1941) Megapalpis Halbert, 1944 Type species Torr enticola (Megapalpis) tenuir os t r i s (K. Viets, 1936) Allotorrenticola Cook, 1967 Type species Torr enticola (Allotorrenticola ) suvarna Cook, 1967 76 KEY TO THE SUBGENERA OF THE GENUS TORRENTICOLA 1 • Third pair of coxae without glandularia 2 Third pair of coxae with glandularia Subgenus Allotorrenticola 2. Palps, P-II + P-III without distinct ventral processes ..... , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Palp, P-II + P-III with ventral processes Subgenus Torrenti cola 3. Hypostome of gnathosoma not broadened and flattened 4 Hypostome of gnathosoma broadened and flattened, P-III + P-IV greatly shortened Subgenus Heteratractides 4. Postero-dorsal gnathosomal process short; chela sickle-shaped; chelicerae much longer than the gnathosoma. Subgenus Megapalpis Postero-dorsal gnathosomal process long; chelicera stout with a hook-shaped chela; chelicerae slightly longer or as long as the gnathosoma. Subgenus Monatractides 77 Torrenticola (Torrenticola) bicornis n. sp. (figs. 60-71, plates I a, b, II d, IV d, VII d, e, f ) Female (figs. 60-64) Dimensions The following are the m1n1mum and maximum dimensions of four females. Dorsum Entire length of dorsum 471 -539µm; maximum length of the dorsal shield 434 - 590µm; maximum width of the dorsal shield 403 - 459µm; length of anterior platelet 130 - 140µm; width of anterior platelet 50 - 59µm; length of posterior platelet 171 - 180µm; maximum width of posterior platelet 62 - 74µm. Venter Entire length of idiosoma 595 - 714µm; maximum width of idiosoma 465 - 536µm; distance between the points of attachment of the fourth pair of legs 234 - 273µm; depth of the gnathosomal bay 105 - 124µm; distance between the gnathosomal bay and the genital field 223 - 242µm; length of the median suture 71 - 99µm; maximum length of the genital field 143 - 155µm; maximum width of the genital field 146 - J61µm. Gnathosoma Length of gnathosoma 279 - 298µm; length of the chelicerae 310 - 329µm; dorsal length/distal height of palp segments; P-I 23 - 26µm/18 - 21µm; P-II 80 - 84µm/32 - 35µm; P-111 49 - 54µm/20 - 26µm; P-IV IOI - 107µm/ 13 - 14µm; length of P-V 15 - J7 µm. Dorsum (fig. 60, plate lb) The dorsum is circular and covered by the dorsal shield and the platelets. All the platelets are free. Posteriorly the dorsal shield exhibits a peripheral area where the sclerotisation differs markedly from the central ' •;_j' +.:.\ : ~ ::~-- ~ .} '. ·y/ 60 " 62 ': ' : 63 64 Figs. 60-64; Torrenticola (Torrenticola) bicornis n . sp., female fig. 60, dorsum; fig. 61, venter ; fig . 62, lateral view of palp; fig . 63 medial view of palp; fig. 64, gnathosoma. 78 area. The ornamentation of the central area is shown in plate lb and the ornamentation of the peripheral area displays a lineated pattern (plate Ild). These ornamentation patterns are peculiar to this species. The muscle attachment marks are prominent and even visible in the external ornamentation. DG are situated lateral to the muscle attachment marks. 1 DG are situated on two small platelets which fit into indentations in 2 the heavily sclerotised area of the shield (fig. 60). These platelets are embedded in the posterior lineated area. The setae associated wi th DG are simple, slender and unbranched. DG are situated terminally, 2 3 ventral to the dorso-ventral curvature of the dorsal shield, thus giving the appearance of being almost ventrally situated. The setae associated with DG are branched. The anterior platelets are smaller, and more 3 angular than the posterior platelets. The peripheral margins of the platelets are thickened. None of the setae on the platelets are branched. Venter (fig. 61, plate Ia) As in the case of the dorsum, the sclerotisation of the venter is not uniform. Latero-posteriorly, the sclerotisation is lighter and this area exhibits the same superficial lineated pattern as the dorsum. The distribution of the setae on the venter is exhibited in fig. 61. The s - setae are situated on very small platelets very close to the heavily 3 sclerotised area. Six pairs of ventro-glandularia are present. VG2 and VG are situated on the heavily sclerotised area and the others on the 4 lineated area. VG are absent. Only the setae associated with VG are 1 7 branched. The excretory opening is situated between the pair of VG • 7 The lateral margins of the anterior coxae are serrated. The gnathosomal bay is V-shaped and its hyaline border is relatively wide and more or less angular. The genital field is almost circular with peripheral thickenings on the genital plates. Nine fine setae are situated on the periphery of each genital plate. Medially each plate carries a number of fine setae. These setae originate internally. Each genital plate carries, internally, on its medial margin a row of six acetabula. 79 Gnathosoma (fig. 62, 63, 64, plate VII d, e, f) The gnathosoma is very slender. The chelicerae are long and the chelae are hooked. The palps are slender and relatively long (figs. 62, 63). P-I carries dorsally a single plumose seta. The flexor side of P-II is straight and carries ventro-distally a relatively long, blunt-ending projection. The head of this projection is covered with pointed denticles. A short seta is situated proximally, halfway down the shaft of the projection. Dorsally P-II is furnished with five long, slender setae and one short seta. P-III is also furnished with a ventro-distal projection. This projection is, however, not as stout or blunt as the one on P-II, but it also carries fine denticles. Both P-II and P-III exhibit a very marked and distinct pattern or ornamentation (see plate VII d). Proxi- mally a seta is borne on the P-III projection. This seta is, however, longer and more slender, than the seta on the P-II projection. P-IV is slightly curved. Ventre-laterally it carries two setal tubercles. The proximal one is situated midway down the length of P-IV. The distal one is situated two thirds down the length of P-IV. The two tubercles are 15µm apart and each has at least 2 apecis; a larger proximal one with a slender seta and a smaller distal one with a relatively stout seta. The setae on the distal tubercle are medially attached and those on the proximal tubercle are laterally attached to the tubercle. Distally P-IV ends in a heavy dorso-medial spine. P-V carries 4 movable claws. Legs (figs. 68-71) The chaetotaxy of the legs is illustrated 1.n figs. 68-71. Male (figs. 65-67) Dimensions The following are the dimensions of two male paratypes respectively : 80 Dorsum Entire length of the dorsum 495 - 508µm; maximum length of the dorsal shield 409 - 459µm; maximum width of the dorsal shield 409 - 434µm; length of anterior platelet 130µm. Width of anterior platelet 74µm; length of posterior platelet 174 - 180µm. Venter Entire length of idiosoma 595 - 643µm; maximum width of idiosoma 488 - 500µm; distance between the points of attachment of the fourth pair of legs 248µm; depth of the gnathosomal bay 93 - 105µm; distance between the gnathosomal bay and the genital field 273 - 304µm; length of the median suture 124 - 143µm; maximum length of the genital field 124 - 136µm; maximum width of the genital field 124 - 130µm. Gnathosoma Length of gnathosoma 282µm; length of chelicerae 304µm; dorsal lengths/ distal heights of P-1 25 - 23/20 - 18µm; P-11 78 - 80/33µm; P-111 49/26 - 25µm; P-IV 101 - 104/11 - 12µm; dorsal length of P-V 16µm. Dorsum (fig. 65) The dorsum of the male resembles to a great extent that of the female. The heavily sclerotised portion of the dorsal shield covers the dorsum almost entirely. The entire periphery of the dorsal shield is thickened to form a continuous peripheral yellow band. Like in the female, DG 1 are situated lateral to the muscle attachment marks and DG are situated on 2 the dorsal shield and not on separate platelets as in the female. The associated setae are situated posteriorly just off the heavily scleroti- sed area. The platelets resemble those of the female. None of the setae associated with the glandularia on the dorsum are branched. Venter (fig. 66) As in the case of the female the sclerotisation of the venter is not uniform. Postero-laterally the sclerotisation is weaker and it exhibits .., . I•<,._ _ \ f ~i- l~:::,. ,_ I~.~ : ',I' \ .~ ll ~.f \. - ----'i !r l- -- l . l _. .- . '' 71 69 Figs . 65- 71; TorrenticoZa (Torrent icoZa) bicornis n . sp . male fig . 65, male dorsum; fig . 66, male venter; fig. ~7, lateral view of male palp; fig . 68 , fourth leg of female; fig . 69, third leg of female; fig. 70, second leg of female; fig . 7 I, first leg of female . 81 the superficial lineated pattern. The distribution of the setae are displayed in fig. 66. Unlike those of the female the s -setae are not 3 situated on separate platelets but on the heavily sclerotised area. Six pairs of ventro-glandularia are present. VG are absent. VG - VG are 1 5 7 situated on the lineated area. None of the setae associated with the ventro-glandularia are branched. The excretory opening as in the female but situated nearer to the ventral shield. The median suture is much longer than in the female and the genital field is consequently situated more posteriorly. The posterior sutures are directed more laterally. The genital field resembles the female genital field although it is slightly smaller. Gnathosoma (fig. 67) The gnathosoma and its palps (fig. 67) are identical to those of the female. The legs do not display any exceptional features. They resemble those of the female. Material Female holotype, 3 female and 3 male paratypes. The holotype, one mal e and one female paratype will be deposited in the Type Collection of the Institute for Zoological Research, P.U. for C.H.E. Potchefstroom, Republic of South Africa. Collection locality 152, 155. Discussion This species belongs to a group of species which all have a distal blunt- ended projection on P-11. This group of species includes T. (Torrenticola ) 82 binga K.O. Viets 1970, T. (Torrenticola ) bomiensi s Cook 1966, T. (Torrentico l a) harrisoni K. Viets 1956, and T. (Torrent i cola ) i nsulicola (Lundblad 1941c). It appears to be most closely related to T. (Torrenticola ) insu licola . The distinguishing features of this new species are: the presence of two well separated tubercles on P-IV, the characteristic lineation of the weakly sclerotised peripheral areas, the ornamentation of the dorsal shield, P-II with one small and five long setae and P-III with three dorsal setae. Age variation is probably very pronounced in Torrenticola . In T. bicornis the dorsum of young individuals is covered with a light, uniformly sclerotised dorsal shield and the edges of the dorsal shield are serrated. In older individuals the sclerotisation of the dorsal shield is heavier and the edges are thickened to form a yellow peripheral band. Postero- laterally, the dorsal shield probably acquires, with age, a peripheral lineated area where the sclerotisation is not as heavy. DG2 and DG are 3 always situated on this peripheral area in the female but not in the male. The peripheral lineated area of the venter also increases in size with age. The following external features exhibit sexual dimorphism in T. bicornis n. sp.; the genital field of males is smaller than those of females; the median suture is longer in males than in females; the posterior sutures are directed more laterally in males and more posteriorly in females. They also appear to be more hooked in females. 83 'l'or>r>enticola (Tor>r> enticola ) eur>ystoma K. Viets, 1956 (figs. 72-78) K. Viets (1956a); K.O. Viets (1965; 1968; 1973) Female (figs. 72, 73, 76, 77) Dimensions The following are the minimum and maximum dimensions of two females identified by K. Viets and mounted by the present author and the dimensions for the paratype female of K. Viets (1956a). Dorsum Entire length of dorsum 500 - 527µm; maximum length of dorsal shield 471 - 490µm; maximum width of dorsal shield 405 - 434µm; length of anterior platelet 118 - 136µm; width of anterior platelet 40 - 43µm; length of the posterior platelet 143 - 158µm; width of the posterior platelet 56 - 68µm. Vente,r Entire length of idiosoma 583 - 60Jµm; maximum width of idiosoma 434 - 546µm; distance between the points of attachment of the fourth pair of legs 236 - 242µm; depth of the gnathosomal bay 115 - 148µm; distance between the gnathosomal bay and the genital field 149 - 155µm; length of the median suture 24 - 40µm; maximum length of the genital field 143 - 150µm; maximum width of the genital field 143 - 150µm. Gnathosoma Length of gnathosoma 298 - 307µm; length · of the chelicerae 347 - 372µm; dorsal length/distal height of palp segments: P-1 29 - 31/25µm; P-II 104 - 106/43 - 46µm; P-111 51 - 54/31µm; P-IV IOI - 104/18µm; dorsal length of P-V 17 - 18µm. 84 Dorsum (fig. 72) The ~ ~ $ r ' ii © 0 @ 135 137 Figs. 134-137; Atractides (Atractides) magnipalpis van Rensburg, 1971, female . fig. 134, dorsum; fig . 135, venter; fig. 136, palp; fig. 137, I-Leg-5,6. 133 Legs (fig. 137) Except for their size the legs do not exhibit any significant features. l-Leg-6 is curved. Material Female holotype. Material is deposited in the Collection of the Museum of Natural History, Basel, Switzerland. Collection Locality 30 Discussion It is exceptional to find such a large animal living in potamophreatic waters. The characteristic feature is the extraordinary large palps. 134 Atractides (Atr actides) micr ophtha lmus Mota~ & Tanasachi, 1948. Mota~ & Tanasachi (1948), Mota~, Tanasachi & Orghidan (1958), Schwoerbel (1961b), van Rensburg (1971), Walter (1947). Female Dimensions This species has been adequately described but for comparative purposes the most important dimensions are given. Length of idiosoma 733µm; width of idiosoma 608µm; length of gonopore with associated shields 156µm; length of acetabular plates 109µm; length of chelicera 227µm; dorsal lengths/distal heights of the palp segments; P-I, 35/35µm; P-II, 121/78µm; P-III, 94/55µm; P-IV, 137/23µm; P-V, 43µm. Material One female. This specimen is deposited in the Collection of the Museum of Natural History, Basel, Switzerland. Collection Locality 45 Discussion The present specimen is, although larger, certainly the same as A. microphthalmus , first described from Rumania. Schwoerbel (1961b, p. 252) suggested that A. microphthalmus and A. denticulatus (Walter 1947) may be synonyms. After a study of the two species the following features have been ascertained: the ventral platelets lying medially to the post coxal glandularia are absent in A. denticulatus ; P-II and P-III of A. denticulatus are ventrally furnished with small teeth which are not present in A. micr ophthalmus; the proximal and distal tubercles of 135 P- IV are much larger, and the heavy seta associated with the proximal tube r c l e i s much longer than in A. microphthalmus . No differences in 1-Leg-5 and 1-Leg-6 could be detected. From the measurements given by the different authors it is clear that the two species are very variable in size. The Black Forest animals are problematic. Provided with the ventral platelets and the small palp tubercles as in A. microphthalmus and teeth on P-II and P-111 as in A. denticulatus they either form a sort of intermediate group between the two species or are just another variant of the same species. Do the Black Forest animals not rather belong to A. microphthalmus ? We can only agree with Schwoerbel when he writes (1961b, p. 252): " ••. the systematic relations of the Atr actides species are very .complicated and the variability of the "species" s eems more significant than we believe." 136 Atr actides (Atr actides ) nitraens i s Laska, 1959 (figs. 138-141) Laska (1959), Mota~ & Tanasachi (1948), van Rensburg (1971). Male Dimensions Length of idiosoma 468µm; width of coxae 312µm; length of gnathosomal bay lOlµm; length of genital field 89µm; width of genital field 105µm; length of gonopore 55µm; length of chelicera 168µm; length of cheliceral claw 47µm; dorsal lengths/distal heights of the palp segments P-I, 27/20µm; P-II, 51/39µm; P-III, 62/3lµm; P-IV, 90/12µm; P-V, 23µm; dorsal lengths of the distal segments of the first l-Leg-4, 109µm; l-Leg-5, 12llµm; l-Leg-6, 105µm. Material One Male. This specimen is deposited in the Collection of the Museum of Natural History, Basel, Switzerland. Collection Locality 5 Discussion Although the present specimen is larger than Laska's specimen it belongs to A. nitraensis. Some error must have been made in measuring the genital field of Laska's specimen. I have measured the genital field on Laska's drawing and found the width and length to be approximately 94µm and not 40µm as printed. The posterior indentation described by Laska appears to be very specific (figs. 138, 141). A. nitraensi s is very closely related to A. szalayi (Mot. & Tan. 1948). I n A. szalayi the anterior pair of ventral setae are situated closely to the fourth pair of coxae and the posterior indentation is absent. I I \\ 139 Figs. 138-141; Atractides (Atrac"tides ) nitraensis Laska, 1959, male. fig. 138, venter; fig. 139, I-Leg-5,6; fig. 140, palp; fig. 141, genital field . 137 Atractides (Atractides) prirrritivus Walter, 1947 (figs. 142 - 151) Mota~ Tanasachi (1948), Schwoerbel (1968b), K. Viets (1959), Walter (1947) van Rensburg (1971). Female Dimensions Length of idiosoma 374µm; width of coxae 254µm; length of genital field including the acetabular plates 109 µm ; length of genital plate 66 µm; width of genital field 125µm; length of gonopore 86µm; length of chelicera 207µm; dorsal lengths/distal heights of the palp segments: P-I, 23/23µm; P-II, 64/47µm; P-III, 66/31µm; P-IV, 94/12µm; P-V, 31µm. Dorsal lengths of the leg segments in µm: I 2 3 4 5 6 TOTAL I-Leg 31 39 66 90 98 78 402 2-Leg 23 35 55 70 78 74 335 3-Leg 23 35 59 82 98 94 391 4-Leg 78 47 98 125 133 105 586 Male (figs. 142, 143, 144, 146) Dimensions Length of idiosoma 390 - 366µm; width of coxae 234 - 234µm; depth of gnathosomal bay 101 - 85µm; length of genital field 101 - 108µm; length of gonopore 39 - 39µm; length of chelicera 144 - 152µm; length of cheliceral claw 47 - 54µm; dorsal lengths/distal heights of the palp segments P-I, 16/16µm; P-II, 47/39µm; P-III, 51/27µm; P-IV, 78/12µm; P-V, 27µm; dorsal lengths of the leg segments in µm: 138 1 2 3 5 Total 4 6 Length I-Leg 31, 27 31, 31 47,43 74,66 74,66 74,70 331,303 2-Leg 23,35 27,35 39,43 59,67 59,62 59,70 266,307 3-Leg 27,35 27,31 43,39 55,62 66,74 59,74 277,315 4-Leg 70, 70 47,39 78,78 94,94 101,101 94,90 484,472 Material Four males ·and one female. This material is deposited in the Collection of the Museum of Natural History, Basel, Switzerland. Collection Locality 5, 12 and 5 (female) Discussion This species has been dealt with by Walter (1947), Mota~ & Tanasachi (1948), K. Viets (1955) and Schwoerbel (1961b) and it is now appropriate to say something about the variation in the species. The length of the idiosoma in the male (fig. 142) may vary between 515 and 360µm in length. The lengths of the legs (fig. 144) of different animals may vary as much as IOOµm, with the smallest variation in the first leg and the largest in the fourth. The palps (fig. 146) may vary in length from 203 to 275µm. The development of the dorsal chitinous plates seems to be fairly constant. Ventrally, however, vari_ation is apparent. In the animals so far described a pair of chitinous plates is always attached to the anterior pair of ventral glandularia (fig. 143). In the Tessin animals these plates are absent in one of the males and very poorly developed in the others but they are completely separated from the 143 ) 146 147 148 ··-:·:· ·. '(} ·.-._~:,-:. ~ .... ::: o® ~ V ¥0 Y3/ 151 150 Figs. 142-151; Atractides (Atractides) prirrritivus (Walter, 1947) fig. 142, male dorsum; fig. 143, male venter; fig. 144, male I-Leg-5,6; fig • . 145, female palp; fig. 146, male palp; fig. 147, male chelicera; fig. 148, female I-Leg-5,6; fig. 149, female venter; fig. 150, female dorsum; fig. 151, female chelicera. 139 glandularia. A pair of chitinous plates is situated anteriorly to the medial pair of glandularia and another pair is situated laterally to the genital field. The former are absent in Schwoerbel's animals and both are absent in the Tessin animals. The posterior margins of the fourth coxae may vary from being concave (see Schwoerbel 1961b, fig. 8b) to convex. In the Tessin animals the acetabula are round whereas the other animals exhibit more or less triangular acetabula. The genital opening is typically situated in the anterior half of the genital field. Except for size, the palps and legs show very little variation in both the males and females. In both sexes I-Leg-6 is uncurved (figs. 144, 148). P-II and P-III bear the typical thorn-like protuberances ventro-distally. The two setae of P-IV are situated on the proximal half of the segment with the heavy medial seta next to the distal seta. I-Leg-6 does not exhibit the genus character and the heavy setae on I-Leg-5 are of equal length, short and blunt. The length of the idiosoma (fig. 149) of the females ranges from 374 to 590µm. The variability of the legs is about the same as in the males. The lengths of the palps (fig. 145) may vary between 239 and 3JOµm but the chaetotaxy is constant and similar in both sexes. Typically the acetabular plates (fig. 149) are drop-shaped with angular acetabula. The acetabular plates are much shorter than the genital opening which lies between two large genital sclerites. Anterior to the pre-genital sclerite is a pair of chitinous plates. 140 Atractides (Atractides ) szalayi Mota~ & Tanasachi, 1948 (figs . 15 2- 160) Mota~, Tanasachi & Orghidan (1958), Laska (1959), Schwoerbel (1961a), van. Rensburg (1971). Female (figs. 152-155) Dimensions Length of idiosoma 530µm; coxal width 320µm; length of genital field 137µm; length of gnathosomal bay 98µm; width of genital field 137µm; length of gonopo.re I l 7µm; dorsal lengths/ distal heigh ts of palp segments: P-I, 27/23µm; P-II, 51/43µm; P-III, 62/35µm; P-IV, 86/l6µm; P-V, 27µm; dorsal lengths of the distal segments of the first leg; I-Leg-4, l25µm; I-Leg-5, 137µm; I-Leg-~, 109µm. Male (figs. 156-160) Dimensions Length of idiosoma 407 - 468µm; width of coxae 304 - 351µm; length of gnathosomal bay 117 - 187µm; length of genital field 78 - 78µm; width of genital field 86 - 82µ~; length of gonopore 31 - 39µm; width of gonopore 8 - 8µm; length of chelicera 148µm; length of cheliceral claw 31 - 39µm; dorsal lengths/distal heights of the palp segments: P-I, 23 - 27/20µm; P-II, 43 - 50/30 - 39µm; P-III, 43 - 55/23 - 27µm; P-IV, 74 - 82/12 - 15µm; le~gth of P-V, 23µm; dorsal lengths of the distal segments of the first leg l-Leg-4, 101 - l17µm; I-Leg-5, 113 - 129µm; I-Leg-5, 90 - 96µm. Material Three males and one female. This material is deposited in the Collection of the Museum of Natural History, Basel, Switzerland. 141 Collection Locality 11, 37 (males), 30 (f emales). Discussion The present female should provisionally be regarded as the female of A. szalayi on the following grounds: the general structure of the coxae (fig. 153~ here they are larger and occupy a larger portion of the venter but this is also the case in A. nitr aensi s Laska 1959; the structure and chaetotaxy of the palps (fig. 155) and legs (fig. 154) the posterior pair of ventral glandularia, each provided with two setae; the relative sizes of the palp segments and the legs. The similarity in the relative sizes of the legs and the palps of the different animals could hardly be described as a case of mere coincidence. Palp segments (figs. 155, 156) expressed as a percentage of the total lengt h of the palp: P-I P- II P-III P-IV P-V Specimen 1 (male) 11 21 21 36 11 Specimen 2 (male) 11 21 23 35 10 Female specimen 10,6 20 24 34 10,6 Mota§ & Tanasachi (1957) 10 20 24 35 11 Schwoerbel (1961a) 9 20 24 36 I I I I 1 • 154 155 156 157 ' '' \ r ' 160 Figs. 152-160; Atractides (Atractides) szalayi (Motas & Tanasachi, 1948) fig. 152, fem~le dorsum; fig. 153, female venter; fig. 154, female I-Leg-5,6; fig. 155, female palp; fig. 156, male palp; fig. 157, male chelicera; fig. 158, male dorsum; fig. 159, male venter; fi g. 160, male I-Leg-5,6. 142 Lengths of the legs (figs. 154, 160) expressed as a percentage of the body length: I-Leg 2-Leg 3-Leg 4-Leg Specimen 1 (male) 112 97 109 176 Specimen 2 (male) 1 1 1 94 IO 1 176 Female specimen 104 85 102 158 Mota~ & Tanasachi (1957) 114 88 110 161 Schwoerbel (1961a) 103 87 91 153 The present species seems to be related to A. ni traensis . Schwoerbel (1961a) suggested that it may not be a very sound species because the features used by Mota~ and his collaborators (1948, 1957) appear to be taxonomically insignificant. The specimens are classified as A. szalayi because of the structure of the coxae (figs. 154, 160). Motas et al . described the posterior margin as a diagnostic feature but this should not be regarded as a specific character. In A. prirrritivus (Walte½ 1947) it was shown that the posterior margin of the fourth pair of coxae may vary from convex to concave. The arrangement of the ventral glandularia and the anterior chitinous portion of the genital field is similar to the type specimen but this could not be seen clearly as in the drawings of the other authors. Although differences do exist between the Swiss animals and the others, they do not justify the creation of a new species. They should provisionally be considered variants until the species can be defined more precisely. 143 8. FAMILY UNIONICOLIDAE Oudemans, 1909 Unionicolidae 0udemans 1909:60; K. Viets 1936:297; Cook 1974:227 Atacinae Thor 1900a:3 Newnaniidae Thor 1923:47 Diagnostic characters The idiosoma may be covered with a soft integument or the integument may be sclerotised due to the development of the ventralia and dorsalia. The sclerotisation may be so extensive as to form complete dorsal and ventral shields. Dorsum The dorsal sclerotisation is extremely variable. The dorsum may be furnished with a number of setae and dorsalia or with a number of closely fitting plates or with a single large shield which may be bordered by a number of peripheral platelets. In the genus Neu.mania the dorsalia may have extremely long projections. The lateral eyes are situated beneath the integument. Venter The coxae are usually arranged in four groups in soft bodied species but in the more heavily sclerotised ones the coxae are usually fused into a single group. The anterior coxae are often furnished with long apodemes but even within the same genus the apodemes may be relatively short. The posterior margins of the fourth coxae are usually furnished with projec tions or apodemes. Glandularia are always absent from the third and fourth coxae. The genital acetabula may vary from two pairs to many and they may either be situated on distinc t acetabular plates or they may be free in the integument around the gonopore. 144 Gnathosoma The gnathosoma, often without an anteriorly projecting hypostome, lies free in the gnathosomal bay. A well developed anchoral process is always present except for some subgenera of Koenikea and Najadicola. The chelicerae may be medially fused. The palps vary from subfamily to sub- family. P-11 and P-111 usually without ventral projections. P-IV is often furnished with chitinous projections bearing setae. A peg-like seta occurs frequently on P-IV. The legs exhibit sexual dimorphism in some cases where IV-Leg-6 of the male is curved. The first leg often carries distinct spatulate setae. The legs are usually furnished with swimming setae. Discussion This family was previously classified under the superfamily Pionae. The Pionae and the Axonopsae are now lumped together in the superfamily Hygrobatoidea. 145 8.1 SUBFAMILY PIONATACINAE Viets 1916 Pionatacinae K. Viets 1916:299; Cook 1974:244 Neumaniinae K. Viets 1931:226; 1936:290 Schadeellinae Lundblad 1938:11 Diagnostic characters The integument of the idiosoma may be soft to moderately sclerotised with exoskeletal elements. Dorsum The dorsum may be soft or it may be furnished with a number of dorsalia, or it may be furnished with closely fitting dorsal plates which may have long projections. Venter The coxae are usually in four groups in soft bodied forms but may be fused to a single group in more heavily sclerotised forms. The suture lines between fused coxae are usually visible. Anterior coxae with long apodemes are connnon. The genital acetabula are usually numerous. In the females the acetabula are typically situated on two acetabular plates. Gnathosoma The gnathosoma is usually without a long hypostome and the chelicerae are normally fused. An anchoral process is connnonly present. The palps are five segmented and occasionally some of the segments may be fused to one another. Projections are often present on P-IV but P-II and P-III are, as a rule, without projections. 146 Sexual dimorphism of the fourth leg of the male may occur. The legs are furnished with simple claws. The proximal segments of the legs are often furnished with spatulate setae. Discussion Cook (1974) pointed out the synonomy of the Neumaniinae and the Pionatacinae. Although the former name is a well established name the latter has priority. 147 8.1.1 Genus Newnania Lebert, 1879 Newnania Lebert 1897; K. Viets 1936:291; Cook 1974:245 Nesaea Neuman 1880:29 Atax Koenike 1881:624 Cochleophorus Piersig 1894:216 Ecpolus Soar 1902:251 Pseudoatax Kent 1n Soar 1911:264 Soarella Koenike 1907:131 Type species Newnania spinipes (Muller, 1776) Diagnostic characters Dorsum The idiosoma is usually weakly sclerotised. The extent of the development of the dorsalia and ventralia is variable but the dorsalia are (at least 1n the females) separated by relatively wide areas of soft integument. Venter The major part of the venter 1s covered by the coxae which are usually arranged in four groups. Coxae two and three are often well separated. Well developed apodemes are often present. There is typically a single pair of acetabular plates but in some females two pairs are present. The number of acetabula is variable. 148 Gnathosoma The chelicerae are usually proximally fused. P-III is mostly furnished with a long conspicuous lateral or dorsal seta. P-IV often with ventro- distal projections. 149 Neumania (Lemienia ) agnewi Bader & van Rensburg, 1968 (figs. 161-165) Bader & van Rensburg (1968) Male Dimensions Length of idiosoma 475µm; width of idiosoma 475µm; width of the genital field; length of the gonopore SOµm; dorsal lengths/distal heights of the palp segments P-I 26/35µm; P-II 80/38µm; P-II 44/42µm; P-IV 78/22µm; P-V 31/13µm. Dorsum (fig. 161) The dorsum proper is clearly demarcated by a fine dorsal furrow. The soft dorsum is furnished with five pairs of glandularia, more or less arranged in two longitudinal rows, and two pairs of chitinous platelets. Each of the posterior pair carries a seta. The dorsally situated excretory pore is flanked by the posterior pair of dorsal platelets. A pair of anterior lateral plates, furnished with setae, and a pair of posterior lateral glandularia are also visible in a dorsal view. Venter (fig. 162) Almost the entire venter is covered by the coxae, the apodemes of which reach to the middle of the fourth pair of coxae. The coxae are arranged in four groups. The first pair carries anteriorly four pairs and posteriorly a single pair of setae. The second pair is furnished with three setae each. Between the second and the third pair of coxae is a pair of glandularia. Each one of the relatively small third pair of coxae is furnished with three setae. The fourth pair is the largest and each is furnished with a cluster of three lateral setae, a pair of postero- medial and a single antero-medial seta. An anterior reaching, strongly chitinised, ridge originates at the point of insertion of the fourth leg. 165 Figs. 161-165; Newncmia (Zerrrienia) agnewi Bader & Van Rensburg,- 1968, male. · fig. 161, dorsum; fig. 162, venter; fig. 163, proximal segments of the first leg; fig. 164, palp; fig. 165, IV-Leg-5,6. 150 The genital field is terminally situated,furnished with fourteen acetabula and a prominent papilla on either side. Anteriorly in the genital f ield are two oblique rows of fine setae. Wedged in between the genital field and the fourth pair of coxae is a pair of glandularia. Another pair of glandularia is situated antero-lateral to the genital field. Palps (fig. 164) P-I is devoid of any setae, P-II carries medially a relatively long seta and laterally three short setae; P-III also carries medially a single seta, but laterally five,of which one is at least twice as long as P-II, P-IV is medially and laterally furnished with a pair of setae. Ventrally P-IV carries two setal tubercles. The smaller one is approximately half way down P-IV and the larger one is almost terminally situated. A f ine seta is associated with each tubercle. Legs (fig. 163, 165) The legs are furnished with typical lanceolate setae. Each of these setae originate from a chitinous tubercle. IV-Leg-6 is strongly curved and IV-Leg-5 is only slightly so. Their chaetotaxy is illustrated in fig. 165. Material The male holotype is deposited in the Collection of the Museum of Natural History, Basel, Switzerland. Collection Locality One male loc. 84. Discussion The present specimen is clo~ely related to Newnania (Lemienia) faZcipe s af ricana K. Viets, 1925 and N. (Lemienia ) faZci pes poZypora Lundblad, 151 1949. The new species differs from them in the following aspects; the excretory pore is situated completely dorsal while it is terminal in the mentioned species, the coxae cover almost the entire venter and the palp chaetotaxy is different. 152 9. FAMILY FELTRIIDAE Viets, 1926 Feltriidae K. Viets 1926:198; Thor 1929:table VII; K. Viets 1936:301; Cook 1974:265. Diagnostic characters Dorsum The dorsum is furnished with a large number of dorsalia and glandularia (fig. 166) which may exhibit varying degrees of fusion. Fusion of the dorsalia and glandularia usually occurs from anterior to posterior so that a fairly large anterior plate is produced. The extent of fusion may in some cases result in the formation of a dorsal shield. The lateral eyes are not in capsules. Venter The coxae are arranged in four groups and in the more heavily sclerotised forms they may be fused to form a single group. The sclerotisation may in some cases be so extensive as to form a ventral shield. In most cases, however, the posterior margins of the fourth coxae are more or less truncate without any projections or apodemes. The two acetabular plates are fused in males but separate in females. Numerous acetabula are present in both sexes. Two pairs of glandularia are situated between the genital field and the fourth pair of coxae. Gnathosoma The gnathosoma is separate from the coxae and bears a well developed anchoral process. A hypostome is absent. The palps are five-segmented and usually without tubercles, rarely there may be a ventral projection on P-II. ANTEROMEDIAL PLATE 0 DORSAL LATERO- PLATE B GLANDULARIA A ·.\\;-.- LATERO- GLANDULARIA B J.-~.--DORSAL .... . f;) PLATE C ·:.?.:..;: - 0 " 1-...\,~=:;7l__j_~ DORSO- GLANDULARIA B LATERO- GLANDULARIA C ®. . . : ~:="_: . , . -,----4--_ DORSAL ~ PLATE E LATERO- GLANDULARIA D 166 Fig. 166; A generalised Feltria dorsum. 153 The legs are devoid of swimming hairs and the ambulacrum may end in one or two clawlets. The third leg of the male may exhibit sexual dimorphism in which case III-Leg-6 is ventrally furnished with highly modified setae. Discussion This family formerly included two subfamilies, viz., the Feltriinae, K. Viets, 1926 and the Azugofeltriinae, Mota~ & Tanasachi, 1948. Cook (1970) placed the Azugofeltriinae in synonomy with the Feltriinae. Because of this synonomy the necessity of a subfamily category falls away. 154 9.1 GENUS Feltria Koenike, 1892 Feltria Koenike 1892:323; K. Viets 1936:302; Cook 1961:118-1 20; 1963:488; 1970:169; 1974:266, 267. Tes tudof elt r i a . Lundblad, 1941:118 Azugofeltr ia Mota9 & Tanasachi 1948:147 Type species Feltr i a (Feltria) rrrinut a Koenike, 1892. Diagnostic charaeters As this family contains a single genus the generic characters are identical to those of the family • . Discussion The family Feltriidae originally contained two subgenera, viz., the sub- genera Feltria and Feltr iella . Uchida (1934) described a third subgenus, i.e., Meso f eltria which was later placed in synonomy with the subgenus Feltrie l la (Immamura 1954). Cook (1963) created the subgenus Neofeltria for a group of North American potamophreatic feltriids. The genus Tes tudof eltr ia Lundblad, 1941, was placed in synonomy with the subgenus Fe l triella (Cook 1974). Cook 1970 lowered the rank of the genus Azugofeltria Motas & Tanasachi, 1948 to subgeneric rank. The genus Felt ria is one of the large potamophreatic groups but only five species have been recorded from Switzerland. This is probably not due to their absence but rather to the limited amount of research that has been done on the Swiss potamophreatic fauna as a whole. Intens i ve collection all over the country but especially in the Tessin may reveal most of the known European and many new species. Of the four species collected, three were new species and the other one was new to the Swiss fauna. 155 Feltria (Feltriella) airoloensis van Rensburg 1971 (figs. 167-173) van Rensburg (1971~ Male Dimensions Length of idiosoma 398µm; width of idiosoma including the lateral plates 304µm; length of coxae 273µm; width of coxae 261µm; width of acetabular plate 242µm; length of acetabular plate 96µm; gonopore 39µm; length of dorsal shield 304µm; width of dorsal shield 261µm; length of antero-lateral plates 179µm; length of postero-lateral plates IOlµm; dorsal lengths/ distal heights of the palp segments P-I, 21/34µm; P-II, 76/59µm; P-III, 36/37µm; P-IV, 88/29µm; length of P-V, 47µm; dorsal lengths of the distal segments of the third leg III-Leg-4, 8lµm; III-Leg-5, 102µm; III-Leg-6, 104µm . Dorsum (fig. 168) The large anterior dorsal shield is composed of the fused antero-medial plate, the dorsal plates A, B, C, D and E and the dorso-glandularia A, B, and C; anterior to the dorsal shield are two antero-lateral shields carrying latero-glandularia A; lateral to the dorsal plate are the postero-lateral plates; latero-glandularia B lie in the space between the dorsal shield and the postero-lateral plates, latero-glandularia C and Dare situated posterior to the postero-lateral plates; posterior to the anterior dorsal shield are the two small posterior dorsal plates representing the two dorso-glandularia D; almost dorsally between the two posterior dorsal plates is the excretory pore. Venter (fig. 167) The coxae are large, covering two thirds of the venter and almost entirely fused on either side but separated medially, the apodemes of the first pair of coxae project posteriorly and laterally to the middle of the fourth pair of coxae; the space between the coxae and the acetabular r . 0 .. . . . o · . · 0 .... 168 169 Figs. 167-170; Fe l t ria (Fe l triella) airoloensis van Rensburg, 1971, male. fig. 167, venter; fig. 168, dorsum; fig. 169, palp; fig. 170, III-Leg-4,5,6. 156 plate is narrow and clearly lineated containing two pairs of free glandularia and one medial ventral platelet; the acetabular plate is large with 45-50 acetabula in each half, anterior and lateral to the gonopore are many fine setae. Gpathosoma and Legs (figs. 169-170) The palps are furnished with heavy plumose setae; palp chaetotaxy is shown in fig. 169; I I-Leg-6 (fig. 170) is without any distinguishing features. Material Male Holotype. This type specimen is deposited in the Collection of the Museum of Natural History Basel, Switzerland. Collection Locality I 30 Discussion The specimen was named after the village near the collection locality. The f ollowing are the diagnostic features: the size and structure of the coxae, the absence of ventro-lateral plates, the genital field covering the extreme posterior end of the body, the presence of the anterior and posterior lateral plates and the arrangement of the lateral and dorsal glandularia and plates. This species seems to be related to Feltria (Feltriella ) amoeneiia Habeeb, 1955 and Feltria (Feltriella) ruhr a nearctica Cook, 1961. 157 Feltria (Feltria) cornuta pauci pora Szalay, 1946. Mota~ & Tanasachi (1947), Mota§, Tanasachi & Orghidan (1947), Schwoerbel (1961b), Szalay (1945b, 1946b), Walter & Mota~ (1927), van Rensburg (1971). Male Unfortunately the only male specimen was slightly damaged so that the length and the width of the body could not be measured but the other features could be studied. Dimensions Dorsal plate length 298µm; dorsal plate width 203µm; coxal length 254µm; coxal width 26lµm; distance between the right and left coxae anteriorly 2µm and posteriorly 6µm; width of the platelets between the coxae and the genital field from medial to lateral 24, 21, 3lµm; acetabular plate length 130µm; acetabular plate width 195µm; dorsal lengths/proximal heights of the palp segments P-1, 23/17µm; P-11, 50/23µm; P-111, 27/27µm; P-IV, 65/5lµm; length of P-V Female Dimensions The following are the dimensions of two females: Length of idiosoma 390, 398µm; width of idiosoma 281, 332µm; dorsal plate width 215, 26lµm; length of coxae 246, 234µm; coxal width 281, 300µm; distance between the right and left coxae anteriorly 3, 3µm; and 15, 24µm posteriorly; distance between the coxae and the acetabular plates 40, 40µm; width of the platelets between the coxae and the genital field from medial to lateral 45, 45µm; 31, 3l µm; 35, 42µm; acetabular plate length 101, l0lµm; acetabular plate width 96, 97µm. 158 Dorsal lengths/proximal heights of the palp segments; P-I, 23/16, 24/17µm; P-II, 42/23, 42/19µm; P-III, 27/21, 29/22 µm; P-IV, 65/15, 59/2l µm; P-V, 38/11, 37/14µm. Material 1 male and two females. This material is deposited in the Museum of Natural History, Basel, Switzerland. Collection Locality 36 (male), 39 and 45 Discussion Simultaneously Szalay (1946) and Mota~ and co-workers described Fe l t ria (Fe l t ria) cornuta paucipora as a new subspecies, and as a new variety of F. cornuta cornut a Walter, 1927 respectively. By coincidence both authors independently chose the same subspecific name (personal communication by Mota~). Schwoerbel (1961b) identified some male speci- mens as F. cornuta paucipora (sensu Szalay) and some females as F. cornuta paucipora (sensu Mota~ & Tanasachi), giving the impression of two subspecies. Mota~ e t al. (1947b) and by personal connnunication stated categorically that their animals were identical to Szalay's and that Szalay's description had the taxonomic priority. The Black Forest animals exhibit rather large differences from the others and it is quite possible that they may be another variety of F. cornuta. 159 FeLtria (FeLtria) f ossea van Rensburg, 1971 (fig. 171-174) Van Rensburg (1971). Male Dimensions Length of idiosoma 359µm; width of coxae 254µm; length of acetabular plate 113µm; width of acetabular plate l79µm; dorsal lengths/distal heights of the palps P-1, 20/27µm; P-II, 54/35µm; P-111, 27/35µm; P-IV, 70/l6µm; length of P-V, 4.3µm; dorsal lengths of the distal segments of the third leg III-Leg-4, 62µm; III-Leg-5, 74µm; III-Leg-6 82µm. Dorsum (fig. 171) The dorsum is covered with a large anterior shield, which includes the anterior medial plate, the dorsal plates A, B, C, D and E, dorso- glandularia A, B, C, and D and a posterior plate composed of the fused dorso-glandularia D; lateral to the large anterior dorsal shield are the four latero-glandularia lying free in the integument. Venter (fig. 174) The idiosoma is oval; the coxal groups are separated medially but fused on either side; the posterior margins of the fourth coxae are rounded; the fourth pair of coxae are further apart than the first two pairs; apodemes of the first pair of coxae extending to the middle of the third pair of coxae; acetabular plate is triangular with a deep slit-like indentation 1n the posterior margin; approximately 30 acetabula on either side of the slit; genital aperture is small and situated anteriorly on the acetabular plate; two pairs of glandularia are situated between the coxae, acetabular plate and the two triangular ventro-lateral plates; two more pairs of glandularia are situated lateral to the ventro-lateral plates; the excretory pore; surrounded by a chitinous ring is situated between the median pair of posterior glandularia. Figs. 171-174; FeZtria (FeZtria) fassea -van .Rensburg, 1971, niaie. · fig. 171, dorsum; fig. 172, palp; fig. 173, III-Leg-6; fig. 174, venter. 160 Gnathosoma (fig. 172) The chaetotaxy of the palps is illustrated in fig. 172. Legs (fig. 173) The ventral side of 111-Leg-6 is furnished with four heavy setae which are .very closely associated (fig. 173). Material Male Holotype. This specimen is deposited in the Collection of The Museum of Natural History, Basel, Switzerland. Collection Locality 30 Discussion This species is named after the river from which it was collected. It has been described as a new species on the basis of: the arrangement and fusion of the dorsal plates; the structure of the acetabular plate with its deep posterior indentation, the presence of the triangular ventro- lateral shields and the structure of the coxae. This species is related to Feltria (Feltria) zschokkei Koenike, 1896. 161 Feltria golatensi s van Rensburg, 1971 (figs. 175-178) van Rensburg (1971). Female Dimensions The dimensions of the paratype are given in parenthesis after those of the holotype. Length of idiosoma 374µm (389µm); width of the coxae 293µm (281µm); length of the coxae 218µm (218µm); width of the genital bay at the base of the fourth pair of coxae 59µm (70µm); length of the genital field 96µm (96µm); width of the genital field 222µm (230µm); length of the gonopore 78µm (78µm); length of the anterior dorsal shield 207µm (211µm) width of the anterior dorsal shield 168µm (168µm); dorsal lengths/distal heights of the palp segments; P-I, 23/27µm (20/27µm); P-II, 73/42µm (66/43µm); P-III, 33/39µm (35/39µm); P-IV, 77/24µm (78/23µm); length of P-V, 47µm (47µm); dorsal lengths of the distal segments of the third leg: III-Leg-4, 62µm (59µm); III-Leg-5, 82µm (82µm); III-Leg-6, 82µm (82µm) . . Dorsum (fig. 175) The dorsum is covered with numerous plates; the largest, the anterior dorsal shield is composed of the fused antero-medial plate with its associated setae, dorsal plates Band D and dorso-glandularia B; antero- lateral to the anterior dorsal shield are the fused dorso-glandularia A and the dorsal plate A; posterolateral to the anterior dorsal shield are the dorsal plates C and D; dorso-glandularia Care situated between the posterior end of the anterior dorsal shield and dorsal plate E; in the paratype dorso-glandularia C and dorsal plate E are fused; dorso- glandularia Dare relatively large; latero-glandularia A, B, C and D lie free in the integument on the lateral margins. 162 Venter (figs. 176, 177) The coxae are medially separated but fused on either side with a conspicuous area of fusion between the two anterior pairs and the two posterior pairs; the coxae cover slightly more than half of the ventral surface; apodemes of the first pair of coxae reach to the anterior margin of the fourth pair; medially the coxae 'end in a large genital bay at the base of the fourth pair of coxae; all the coxae are richly furnished with the setae as shown in fig. 176, the ventro-glandularia lie free in the large space between the coxae and the acetabular plates which cover the posterior third of the venter; the acetabular plates are triangular in shape (fig. 177). with approximately 40-50 acetabula on either side; medial border of the acetabular plate is furnished with three long setae; the gonopore lies between the relatively large anterior and posterior acetabular plates. Gnathosoma (fig. 178) The chaetotaxy of the palp is illustrated in (fig. 178) The legs do not exhibit any extraordinary features. Material Female holotype and one female paratype. This material is deposited in the Collection of the Museum of Natural History, Basel, Switzerland. Dis~ussion Only two femalJ specimens were found and it was therefore not possible to determine the subgenus. This species was named after the stream from which it was collected. The species is closely related to F. (Feltriella) ruhra Piersig, 1898. The coxae are similar in the two species but the .. . . . . . . . . . . . . . . ·~.,,. . . . . \;n,, . ·.; :__ ·._.-: .·. :"--. ·:._:/ ,._;) =p; .; · .. ... <2 ~ 0 (\ ;g; (':'.'i) (~t;) 175 Figs. 175-178; FeZtria goZatensis van Rensburg, 1971, female. fig. 175, dorsum; fig. 176, venter; fig. 177, acetabular plate; fig. 178, palp. 163 ventro-glandularia of F. goZatensis are smaller and the lateral plate- lets are absent and the setation of the acetabular plate differs. The greatest difference between the two species is in the dorsum. In F. rubra dorso-glandularia A is incorporated in the anterior dorsal shield. In F. goZatensis dorsal plate A and dorso-glandularia A are fused to form a separate element. The form of the anterior dorsal shield is typical. Dorso-glandularia C and dorsal plate E are clearly separated from the anterior dorsal shield and the two may be fused. The posterior plates are larger than in F. rubra. The similarity with F. rubra suggests that this species may belong to the subgenus FeltrieZZa. 164 10. FAMILY ATURIDAE Thor, 1900 Aturidae Thor 1900a:4; Cook 1974:289. Brachypodidae Thor 1900a:4; Oudemans 1923:76; Sokolow 1930:196 Axonopsidae K. Viets 1929:169; K. Viets 1936:365 Ljaniidae Thor 1929:162 Diagnostic characters The idiosoma is typically dorso-ventrally flattened except in the Frontipodopsinae where it is laterally compressed. Dorsum The dorsal shield is usually heavily sc.lerotised and in some cases fused with the venter. The dorsum may be covered with a large dorsal shield and a number of closely fitting peripheral platelets. The glandularia are variously distributed. Venter The venter is typically heavily sclerotised. The coxae are always in a single group which is fused with the ventral shield. The genital field, consisting of the acetabular plates, acetabula and gonopore, is more or less terminally situated. The acetabula may vary in number from two pairs to many. They are always situated on the acetabular plates which may be fused to the ventral shield without a suture line. Gnathosoma The gnathosoma 1s usually free from the coxae except in the genera Szalayella and Karlvietsia . . The palps are five-segmented and never uncate. P-II and P-IV are often furnished with ventral projections. 165 The legs may exhibit some form of sexual dimorphism. The fourth leg of the male is usually modified. Discussion The family was previously included in the superfamily Axonopsae K. Viets, 1931. Cook (1974) created the superfamily Hygrobatoidea which includes the superfamilies Pionae K. Viets, 1930 and the Axonopsae K. Viets, 1931. These two superfamilies now fall away. Originally the Axonopsidae and the Aturidae were two well defined families. With the description of new species from various parts of the world many transitional forms between the two families occurred and the Axonopsidae, now gradually merge into the Aturidae. The two families should therefore be regarded as synonyms. On the principle of priority the family name Aturidae should be accepted. 166 10.1 SUBFAMILY ATURINAE Thor, 1900 Aturinae Thor 1900a:4; K. Viets 1936:376; Cook 1974:357. Diagnostic characters The idiosoma 1s always dorso-ventrally flattened and well sclerotised. Dorsum The dorsum is covered by a single dorsal shield furnished with glandularia which may be variously distributed. The dorsal furrow is always evident. Venter The coxae are fused with the ventral shield and the sutures are almost totally obliterated. The anterior coxae project well beyond the anterior end of the idiosoma. The genital acetabula (eight pairs or more) are situated on acetabular plates which are fused with the ventral shield except in the genus Phreatobrachypoda where the acetabular plates of the female are free. Gnathosoma The gnathosoma is always free in the gnathosomal bay. P-II is often furnished with a ventral projection. The distal segments. of the second, third or fourth legs may be modified. The ambulacra are usually furnished with clawlets. 167 10.1.1 Genus At urus Kramer, 1875 Aturus Kramer 1875:309; K. Viets 1936:376;Mitchell 1954:350; Cook 1974:358 Type species Aturus scaber Kramer, 1875 Diagnos~ic characters The dorsum (fig. 179) is covered with the single dorsal shield which is demarcated by a peripheral furrow containing the four pairs of latero- glandularia. The dorsal shield is usually fused with the venter in males and it is furnished with five pairs of dorso-glandularia. The excretory pore is dorsally situated. In the males the posterior part of the venter is furnished with setae and often vesicular setae (figs. 180, 181). There are usually many acetabula situated posteriorly on the periphery of the body. The rows of acetabula may reach antero-laterally up to the level of insertion of the fourth pair of legs. A ventral projection on P-II is not uncommon. IV-Leg-4 of the male usually exhibits sexual dimorphism. Discussion As in the allied genus Kongsbergia, the different species of Aturus are chiefly based on the characters of the male. The females can only be identified with absolute certainty if the animals are found in copulation. In the male the following characters are of taxonomic significance: the structure of IV-Leg-4; the palps; the structure of the genital field, i.e., the number of acetabula; the vesicular setae; the arrangement of the dorso- and latero-glandularia and the structure of their associated setae. Other features which are also used are the integumentary markings and the muscle scars on the inner surface of the integument. The arrangement of the dorso- and latero-glandularia is a significant taxonomic feature (fig. 179). Latero-glandularia are situated in the dorsal furrow between the ventral and dorsal shields. They may be variably DORSAL FURROW DORSO- GLANDULARIA I LATERO- GLANDULARIA I ,0 i DORSO- LATERO- GLANDULARIA II y 0, GLANDULARIA II DORSO- - GLANDULARIA III LATERO:.. GLANDULARIA II I DORSO- GLANDULARIA IV LATERO- GLANDULARIA IV l DORSAL SHIELD EXCRETORY PORE 179 Fig. 179; A generalised Aturus-dorsum 168 distributed in the dorsal furrow. There is a tendency for latero- glandularia III and IV to shift closer together and they may, in extreme cases, appear to be fused. The structure of the setae associated with the latero-glandularia is variable. The seta associated with latero- glandularia II may in some cases be forked and those of latero-glandularia I may be heavier than the other glandularial setae. The dorsal shield is furnished with five pairs of dorso-glandularia "Relative position of II and III shift in some species but III is always mesal to II. Dorso-glandularia IV and V are usually near the posterior margin, IV is always lateral to V." (Mitchell 1954). The setae associated with the dorso-glandularia may also be differentiated. In a number of species the seta associated with dorso-glandularia I is flattened and forked. In many Aturus-males specialised setae occur next to the genital cleft. K. Viets ( 1936) called them "keulenformiges oder ahnliches, hyalines Gebilde" and Mitchell called them (1954) "paddle-shaped". In the speci- mens studied the setae appeared to be bladder-like. In fact, in some specimens they were ruptured, These setae are hollow hyaline structures and to call them vesicular setae seems to be appropriate, In females the species characters are not so pronounced. The distinguish- ing features in the male, i.e., the structure of the fourth leg and the characteristic structure of the dorsum cannot be observed in the female. The females are unspecialised and less differentiated. The characters used for taxonomy are the genital field, the palps which are usually similar to those in the male, and the coxae with their mark~ngs. 169 Aturus le l gioensis van Rensburg, 1971 (figs. 180-186) van Rensburg (1971l Male (figs. 180-183) Dimensions Length of idiosoma 390µm; width of idiosoma 300µm; length of dorsal shield 234µm; length of genital cleft 57µm; dorsal lengths/distal heights of palp segments P-I 24/17µm; P-II 51/39µm; (SOµm with the ventral projection); P- III, 29/27µm; P-IV, 74/14µm; P-V, 31µm; dorsal lengths of the distal segments of the fourth leg; IV-Leg-2, 82µm; IV-Leg-3, 78µm; IV-Leg-4, IOl µm; IV-Leg-6, 163µm. Dotsum (fig. 181) Dorsal and ventral shields are present; the dorsal shield furnished with five pairs of glandularia situated on the posterior half of the dorsum; the setae associated with dorso-glandularia I are heavy, flat and the terminal end forked; the dorsal furrow is widened to acconnnodate the latero-glandularia; posterior latero-glandularia III and IV situated closely together and furnished with fine setae; latero-glandularium II situated between latero-glandularia I and III, is furnished with a heavy, flat, forked seta; the ventral shield extends onto the dorsal side of the body and posterior to latero-glandularia III and IV, it is covered with a cluster of setae. Venter (fig. 180) The coxae do not exhibit any extraordinary features; the posterior margin of the body is furnished with seven t o nine acetabul a on either side of the genital cleft and ventrally with one pair of acetabula surrounded by four pairs of setae; between the acetabula the body is richly furnished with setae and the two pairs of vesicular setae are attached on either side of the genital cleft. One pair of vesicular setae is ruptured. 170 Gnathosoma (fig. 182) The palps are relatively short but stout; P-I with one dorsal seta, P-II with three medial and two lateral setae, the distal projection is situated ventro-laterally; P-III with one medial seta; P-IV with one distal dorso- medial seta, one ventro-medial seta and one long ventro-lateral seta, the flexor surface of this segment is strongly convex; P-V is furnished with one prominent ventro-medial seta and a cluster of terminal dorsal setae. Legs (fig. 183) The chaetotaxy o_f the fourth leg is illustrated in fig. 183; the setae on IV-Leg-5 and IV-Leg-6 are dominated by two large, flat setae surrounded by a number of setae of various sizes. The other legs do not exhibit any extraordinary features. Female (figs. 184-186) Dimensions Length of idiosoma 436µm; width of idiosoma 312µm; length of the dorsal shield 328µm; width of the dorsal shield 273µm; dorsal lengths/distal heights of the palp segmen}s P-I, 24/17µm; P-II, 51/36µm (SOµm including the ventral projection); P-III 29/26µm; P-IV, 70/16µm; P-V, 30µm. Dorsum (fig. 186) The dorsal shield is present but simpler than that of the male; dorso- glandularia I and II absent; dorso-glandularia III are placed on the same level as latero-glandularia III; dorso-glandularia IV and V are situated near the posterior margin of the dorsal shield; the four latero-glandularia lie equally distanciated in the narrow dorsal furrow. There are no specialised setae associated with the glandularia. ~ Figs. 180-186; Aturus (Aturus) ZeZgioensis van Rensburg, 1971 fig. 180, male venter; fig. 181, male dorsum; fig. 182, male palp; fig. 183, male fourth leg; fig. 184, female palp; fig. 185, female venter; fig. 186, female dorsum. 171 Venter (fig. 185) Ventral shield present; the coxae are similar to those of the male; 11-12 acetabula in a row on either side on the periphery. Immediately anterior to the acetabular rows are two pairs of ventral glandularia; posterior to the two acetabular rows are a pair of unsclerotised cuticular projections furnished with a pair of glandularia. Gnathosoma (fig. 184) The palps are similar to those of the male. Material Male holotype, four male paratypes and nine female paratypes. The material is deposited in the Collection of the Museum of Natural History, Basel, Switzerland. Collection Locality 5. Discussion The species was named after the village near the collection locality. It belongs to a group of Aturus-species, which from now on shall be called natangensis-group after Aturus natangensis Protz 1900. All the males of this group have the following features in common: 1. The seta of latero-glandularia II is heavy, flat and forked. 2. The seta of dorso-glandularia I is heavy, flat and forked. 3. Latero-glandularia III and IV are situated very close together and may appear to be fused. 172 4. Posteriorly the body is furnished with two pairs of vesicular setae a t t ached on either side of the genital cleft. Due to the undifferent i ated nature of the Atu.rus - f emales these similarities could not be f ound amongst the f emales of this group. The following species and possibly others belong to this group: A. alpheus Lundblad, 1951 A. asserculatus asser culatus Walter, 1906 A. asserculatus serratus Viets, 1922 A. atlantis Lundblad, 1942 A. complexus Sokolow, 1934 A. converge·ns Walter, 1926 A. deceptor Habeeb, 1953 A. gallicus K. Viets, 1939 A. hoplomachus Mitchell, 1954 A. intermedius Protz, 1900 A. Zelgioensis Van Rensburg, 1971 A. natangensis Protz, 1900 A. sangabrielensis Habeeb, 1961 A. scitulus Angelier, 1950 The present species is closely related to A. natangensis and A. inter- medius . It differs from the two mentioned species in having only one pair of ventral acetabula, flanked by four pairs of setae in the male. Posteriorly the new species is furnished with fewer setae than A. intermedius but more than A. natangensis . According to the drawings of the other authors, the chaetotaxy of the palps also appears to differ. Distally IV-Leg-4 is flatter and broader in A. natangensi s and narrower in A. intermedius . In A. intermedius the seta of latero-glandularia I 1s forked and the arrangement of the glandularia is different. In A. natangensis the eight to ten acetabula are arranged in a single row while in A. Zelgioensi s the eleven to twelve acetabula are placed on separate levels and the setae on the venter are more numerous. 173 10. 1.2 Genus Kongsbergia Thor, 1899 Kongsbergia Thor 1899:1; K. Viets 1936:386; Cook 1974:359 Hj a:l'dalia Thor 1901:673 Aturellus Piersig 1901:18 Type species Kongsber gia materna Thor, 1899 Diagnostic characters The dorsal shield is completely separate and the excretory pore is situated dorsally. A ventral shield is always present. The genital acetabula are numerous and postero-peripherally situated. P-II always higher than the other palp segments and P-II may also be furnished with proximal ventral projections. The fourth leg of the male exhibits sexual dimorphism (figs. 187, 195, 197). Some of the setae attached to IV-Leg-5 are usually enlarged and somewhat flattened. Discussion The taxonomy of the genus is rather complicated, especially in the case of the females. The males are furnished with special setae on IV-Leg-4 and IV-Leg-5, P-II carries proximally on its ventral side some characte- ristic chitinous projections and the ventral setae on P-IV are usually typically situated. In the female IV-Leg-4 and IV-Leg-5 are taxonomic- ally insignificant. The palps are also furnished with chitinous projections but these are subjected to a great degree of variation as has been indicated for Kongsbergia angusta Walter, 1947, and for Kongsbergia pectinigera Mota~ & Tanasachi, 1946 (Schwoerbel 1961b). The ventral setae on P-IV are typical in Kongsbergia dentat a Walter, 1947, but in most other cases their use for taxonomic purposes is limited. The result is that it is almost impossible to identify females unless the males are present in the same sample. It is clear that the 174 descriptions of new species from females only could be very confusing, and should be avoided as far as possible. The three Kongsbergia-species collected, were all known to science and described by Walter (1947) from Switzerland. In the present study the collected specimens are compared with Walter's specimens and with other records from other European countries. All the specimens were collected from the Swiss Jura, where they occur in large numbers. Representatives of this genus were completely absent from the 33 samples collected from the Tessin. This is remarkable because members of the closely allied genus, Aturus occurred quite frequently in the Tessin. 175 Kongsbergia (Kongsbergia) angusta Walter 1947 (figs. 187, 188) Anglier, E. (1950), K. Viets (1955, 1959), Walter (1947), van Rensburg (1971). Female Dimensions The dimensions for the present animals are the range of the values f or ten females. The dimensions of Walter (1947), Angelier (1950) and K. Viets (1955) respectively are given in parenthesis. Ventral length of idiosoma 374 - 329µm (430µm), (420µm), (405µm); dorsal length of idiosoma 312 - 374µm (395µm), (--), (363µm); width of idiosoma 226 - 273µm (250µm), (240µm), (205µm); gnathosomal bay 62 - 93µm (---); dorsal lengths/distal heights of palp joints, P-I, 20 - 24/23 - 24µm (20/-µm), (25/17µm), (18/-µm); P-II, 54 - 65/34 - 42µm (65/-µm), (70/50µm), (66/-µm); P-III, 31 - 36/26 ~ 34µm (27/33µm), (33/-µm); P-IV, 71 - 87/15 - 20µm (85/-µm), (87/-µm); P-V, 34 - 36/- - µm (43/-µm) (32/-µm), (29/-µm). Male Dimensions The dimensions of the two specimens are given,with the dimensions of Walter (1947) and Angelier (1950) respectivelY, in parenthesis. Ventral length of idiosoma 363 - 387µm (--347µm); dorsal length of idiosoma 316 - 324µm (370--µm); anterior width of idiosoma 233 - 234µm (---µm); posterior width of idiosoma 203 - 218µm (220 - 205µm); length of gnathosomal bay 74 - 78µm (---µm); dorsal lengths/distal heights of palp segments; P-I, 23/26µm (25/-µm) (20/15µm); P-II, 76/47µm (90/-µm) (87/55µm); P-III, 40/37µm (45/-µm) (33/35µm); P-IV, 93/17µm (105/-µm ) (85/25 m); P-V, 40/-µm (43/-µm) (37/-µm); dorsal lengths of the fourth leg, IV-Leg-4, 78 - 82µm (90 - 70µm); I V-Leg-5, 70 - 70µm; (85µm) (60µm); IV-Leg-6, 98 - l0l µm (102µm) (85µm). I i I \ l t 1 i 187 ' Figs. 187- 188; Korigsbergia (Ko_ngsbe_rgia) cmgusta Walter, 194 7 fig. 187, distal segments of the male fourth leg; fig. 188, distal segments of the female second leg. 176 Material Two males and eleven females. This material is deposited in the Collection of the Museum of Natural History, Basel, Switzerland. Collection Localities 34, 36, 39 and 44. Discussion The male of this species is charact~ristic, especially the structure of of the fourth leg (fig. 187). The dorsal anterior glandularial project- ions are well defined and the anterior dorsal suture is clear. The palps are taxonomically important. P-II is furnished with three to four dis- similar ventral projections of which one or two of the central ones are double-coned. The disto-ventral setae are situated laterally and medially to the projection,on the proximal edge of the characteristic distal con- cavity of P-IV. In the female the species characteristics are not so pronounced. The palps bear the most important taxonomic characters, although they are subjected to considerable variation not only in size, but also in structure. The projections on P-II may vary from two to many. They may be present as individual cones or as double-coned projections, mostly slightly lateral to the ventral median line. Of the two setae on P-IV the median one is shorter. In one specimen two medial flexor setae, situated next to each other, were present. The three anterior pairs of legs are of taxonomic importance. The fourth and fifth segments of these legs are flattened and strongly convex on the flexor side and the actual joints are very narrow (fig. 188). 177 Kongsbergia (Kongsbergia) dentata Walte~ 1947 (Figs. 189-195) Angelier, E. (1950), K. Viets (1955), Walter (1947), van Rensburg (1971). Female Dimensions The minimum and maximum dimensions of five animals are given~with those of Angelier (1950) and Walter (1947) respectivelz in parenthesis. Dorsal length of idiosoma 367 - 390µm (375µm) (420µm); ventral length of idiosoma 382 - 429µm (410µm) (-µm); width of idiosoma 300 - 312µm; (255 µm) (290µm); length of gnathosomal bay 86 - 94 m (-µm) (-µm); dorsal lengths/distal heights of palp segments: P-I, 23 - 27/21 - 23µm (25/-/15µm) (22/-/-µm); P-II, 74 - 49/23 - 27 µm (78/33µm) (75/-/-µm); P-III, 27 - 31/24 - 26µm (26/24µm) (30/-µm); P-IV, 85 - 101/14 - 16µm (97/20µm) (105/-µm); length of P-V, 45 - 50µm (50µm) (50µm); dorsal lengths of the legs: I-Leg, ·385 - 354µm (290µm) (310µm); II-Leg, 289 - 35l µm (320µm) (325µm); III-Leg, 335 - 390µm (350µm); IV-Leg, 468 - 488µm (420µm) (500µm). Male Dimensions The dimensions of the present specimen are given,with those of Angelier (1950) and Walter (1947) respective!~ in parenthesis. Dorsal length of idiosoma 359 m (325µm) (400µm); ventral length of idiosoma 390µm (360µm) (-µm); width of idiosoma 242µm (215µm) (260µm); length of gnathosomal bay 62µm (- ) (-); dorsal lengths/distal heights of t he palp segments: P-I, 29/25 µm (25/15 µm) (20/-µm); P-II, 92/28µm (85/37µm) (100/-µm); P-III, 25/29µm (25/23µm) (30/-µm); P-IV, 97/22µm (95/20µm) (110/-µm); P-V, 47/-µm (45/-µm) (55/-µm); dorsal lengths of the distal segments of the legs: IV-Leg-4, 88µm (75µm) (90µm); IV-Leg-5, 79 µm (95 µm); IV-Leg-6, 116µm (l00µm) (135 µm). 191 , 192 194 195 193 .Figs. 189-195; Kongsbe_rgia ( Kongsbe_rgia) dentata Walter, 1947 fig. 189, mal~ dorsum; fig . 190, male venter; fig. 191, female vente,r ; fig. 192, male IV-Leg-2; fig. 193, female palp; fig. 194, male palp; fig. 195, distal segments of male fourth leg. 178 Material One male and twelve females. This material is deposited in the Collection of the Museum of Natural History, Basel, Switzerland. Collection Locality 36, 39, 42 and 45 Discussion This species is well defined and adequately described. It is character- ised by the lateral tooth-like projections of the first pair of coxae (figs. 190, 191), the slenderness of the female palp segments (fig. 194), especially of P-IV and P-V. IV-Leg-5 (fig. 195) and the structure of P-IV (fig. 193) are characteristic for the male. This species is known from Switzerland, Germany and France. 179 Kongsber gia (Kongsber gia) pectinata Walter, 1947 (figs. 196, 197) Angelier, E. (1949), (1950), Mota~, Tanasachi & Botnariuc (1948), Szalay (1954b, 1948), K. Viets ( 1955), Walter (1947), van Rensburg (1971 ), Male Dimensions Ventral length of idiosoma 468µm; dorsal length of idiosoma 398µm; anterior width of idiosoma 362µm; gnathosomal bay length 117µm; dorsal lengths/distal heights of the palp segments; P-I, 31/29µm; P-II, 90/34µm; P-III, 34/33µm; P-IV, 126/16µm; P-V, 33/-µm; dorsal lengths of the distal segments of the legs; IV-Leg-4 95 µm; IV-Leg-5 71 µm; IV-Leg-6 l2l µm. Material One male. This specimen is deposited in the Collection of the Museum of Natural History, Basel, Switzerland. Collection Locality 43 Discussion After a study of Walter ' s specimens it was concluded that the present specimen belongs to the same species. Small differences, however, are evident. Walter's specimens are longer and have a smaller body width. This difference is probably due to the excessive flattening during preparation. Due to this flattening the acetabula could clearly be seen, which is not the case in Walter ' s specimens. The acetabula are scattered in more or less three rows. Walter observed that the acetabula were \ \ \ \ ', \ \ \ '\. \ ' ·' \. \. '\. ,\ " \' , \ I I ) I J I I ( I ( I ) 196 I I I /' I I 197 I \ Figs, 196- -19 7; Kongsbergia ( Kongsbergia) pect i nata Walter, 194 7. fig. 196, female palp; fig. 197, distal segments of the male fourth leg. 180 arranged in a double row. There is also a difference in the chaetotaxy of IV-Leg-4, but the number of spatulate setae on the distal end of this segment in Walter's specimen could not be seen clearly. These slight differences should not influence the taxonomic position of our specimen. This species is closely related to a number of allied species, i.e., Kongsbergia aZata Szalay, 1945, K. pectinigera Mota~ & Tanasachi, 1946 and K. dentata Walter, 1947. Although closely related, K. dentata and K. pectiniger a appear to be two different species and not synonomous to K. pectinata. K. aZata and K. pectinata have more in connnon, so much so that they may actually be synonyms but the following differences are problematic. K. aZata K. pecti nat a Flexer side of P-II Two lateral horn-like 1 three-pronged projections medial projection and one cone-like lateral projection. P-IV .. P-V 115 .. 28µm 126 - 135 .. 33 - 37µm Acetabula 2 - 3 rows 2 rows (Walter 1947) 2 - 3 rows (present specimens) Proximal heavy seta Horn-like, epectinate Pectinate of IV-Leg-5 When IV-Leg-5 lies in a certain position the comb-like structure of the proximal heavy seta is not evident and it appears horn-like. This may have been the case in Szalay's specimens,although it seems unlikely to have happened to such an experienced acarologist. From my specimen it is clear that the difference in the acetabular arrangement of the two species does not exist. The size difference in the palps may be due to variation. The only major difference which remains, is the difference in the cuticular projections on the flexor side of P-II. Without study- ing Szalay's specimen it is impossible to make a final decision on the synonomy of the two species. Further studies of the variation of K. aZata and K. pect inata may prove or disprove this synonomy. I 8 I 11. FAMILY MOMONIIDAE K. Viets, 1926 Momoniidae K. Viets 1926:195, 197; Lundblad 1930:57; Mota~ & Tanasachi 1946:42, 43; Cook 1974:168. Diagnostic characters The representatives of this family are mostly heavily sclerotised, In the genus Momonides the idiosoma is covered with numerous sclerites, In only one species, Momoni a kareZica (Sokolow, 1926) the integument is soft and unsclerotised. When heavily sclerotised, the dorsum may be covered with a large single dorsal shield or with two dorsal plates which may be equal in size but more often the posterior plate is larger than the anterior one, The venter may be p~rtly or entirely covered by the ventral shield. The anterior coxal groups may be completely fused with the ventral shield or they may be .separated from the ventral shield by an anthrodial membrane. The glandularia associated with the third coxae may be free or incorporated in the third coxae. There are usually three pairs of genital acetabula. Stygomomonia ripaira Habeeb have four pairs of genital acetabula and in the genus Momonides each of the three pairs has been subdivided into three pairs of acetabular groups. In the females the acetabula are situated on acetabular plates but in the males t~e acetabula may either be situated on poorly deve l oped acetabular plates which are fused with the ventral shield1 as i n Stygomomonia, or they may occur in the gonopore as in Momonia . The gnathosoma is not fused to the coxae. P-IV is ventrally f urnished with two setae of which one or both may be thickened. Apart from being highly modified the first pair of legs may exhib i t sexual dimorphism, I-Leg-5 of the male is thickened and the claw socket of I-Leg-6 is modified to form a grasping organ, 182 Discussion This family was previously classified under the superfamily Mideopsae. Cook (1974) transferred the family to the superfamily Arrenuroidea. 183 II.I SUBFAMILY STYGOMOMONIINAE Mota~ & Tanasachi, 1947 Stygomomonii nae Mota~ & Tanasachi 1947:43; Cook 1974:327. Diagnostic characters The idiosoma is sclerotised with dorsal and ventral shields. The dorsal shield may be entire or divided into an anterior and a posterior plate. With the exception of Stygomomonia riparia Habeeb which has four pairs of genital acetabula, there are typically three pairs of genital acetabula. The acetabular plates are free in the female but incorporated in the ventral shield in the male. 11.1.1 Genus Stygomomonia Szalay, 1943. Stygomomonia Szalay 1943:58; Mota~ & Tanasachi 1947:43; Cook 1958:211 Type species Stygomomonia (Stygomomonia) l atipes Szalay, 1943. Diagnostic characters Same as for the subfamily. Discussion This typical potamophreatic-genus is represented in Switzerland by only one species, i.e., Stygomomonia lati pes Szalay, 1943. The variation of the species is evident from the numerous descriptions by different authors. The intraspecific variation of the genus was treated by Cook (1968). He concluded that the most significant taxonomic characters are the proportions of the distal segments of the first leg, the peripheral thickening of the dorsal shield and the degree of fusion of the posterior ventral platelets. These features were used in the evaluation of the present specimens. 184 Stygomomonia (Stygomomonia) latipes Szalay, 1943 (figs. 198-201) Adults The adults of this species have been adequately described by Mota~ & Tanasachi (1946), Motaj, Tanasachi & Bothnariuc (1948), Szalay (1943), K. Viets (1955a) and Walter (1947). A further description of the adults therefore seems superfluous. A few remarks on the variability of this _species do, however, seem necessary. Walter (1947) described three species of Stygomomonia, S . ju.rassica and S. transversell'ia from Switzerland and S. gracilis from Rumania. Apparently he described them chiefly on the appearance of the coxal sutures and the suture between the fourth pair of coxae and the posterior ventral plate. This unfortunately proved greatly variable and therefore unsuitable for taxonomic use (Cook 1968). In 78 adult individuals from seven different localities, t he suture line between the fourth pair of coxae and the posterior ventral plate varied from transverse to posteriorly directed. No differences in the proportions of the distal segments of the first leg could be observed; the peripheral thickening of the dorsal shield does not exhibit any large differences and the posterior ventral glandularial plates are fused to form a single platelet on either side of the excretory pore. These conditions were also observed in Walter's type specimens. Mota~, Tanasachi & Botnariuc (1948) regard S . ju.rassica and S . t r ans versell'ia as varieties of S. latipes. K. Viets (1955a) correctly identified S . graci Zi s as S . Zatipes, but he recognised ("wenn auch keine sog. 'gute Art"') Stygomomonia Zatipes t ransversell'ia (Walte½ 1947) as a subspecies of S. Zatipes on the following grounds; the visibility of the dorsal platelets in a dorsal view - a mere preparational difficulty; the transverse suture between the fourth coxae and the posterior ventral plate - an unsuitable taxonomic feature and incidently the condition in Szalay's type specimen; the position of the excretory pore - a feature which cannot be observed in Walter's type specimen. It is therefore suggested that S . gr aci lis Walte½ 1947; S. ju.rassica Walter, 19"47; S. transversaria Walter, 1947; and its synonym S . Zat ipes transversell'ia (Walter, 1947) all be considered synonyms of S . latipes Szalay, 1943. 185 Dimensions Dorsum Length of the anterior dorsal plate 144µm; width of anterior dorsal plate 24l µm; length of posterior dorsal plate 187µm; posterior dorsal plate _anteriorly 246 µm and posteriorly 202 µm in width; distance between anterior dorsal plates 33µm. Venter Length of idiosoma 398µm; width of idiosoma 343µm; coxae and ventral shield 312µm in length and 304µm in width; depth of gnathosomal bay 134µm. Gnathosoma Dorsal lengths/distal heights of the palp segments: P-I, 14/lSµm; P-II, 34/2l µm; P-III, 21/17 µm; P-IV, 36/-µm; P-V, 34/-µm; dorsal lengths of the distal segments of the first leg; l-Leg-4, 67µm; l-Leg-5, 135µm; l-Leg-6, 68µm. Dorsum (fig. 198) The dorsum is covered by an anterior and a posterior dorsal plate. In the adult these plates are fused, The anterior plate is furnished with a pair of antero-medial setae and a pair of lateral glandularia. The posterior dorsal plate carries three pairs of peripheral glandularia. Antero-medially is a pair of glandularia furnished with two pairs of setae. Lateral to the anterior pair of glandularia are the eyes and another pair of glandularia. On the level of the unsclerotised area between the plates is a pair of lateral glandularia and lateral to the posterior plate is a single pair of glandularia. 200 Figs. 198-201; Sq1gomomonia (Sq1gomomonia) Zatipes Walter, 1947, nymph. fig. 198, dorsum; fig. 199, venter; fig. 2po, palp; fig. 201, I-Leg-4,5,6. 186 Venter (fig. 199) The ventral shield covers about 75% of the anterior surface area of the venter. The first and second pairs of coxae are distinct, Between the second and third coxae is a pair of glandularia. The third and fourth coxae are fused with the ventral shield. Medially the suture area between the right and left sides is visible. The suture lines between the third and the fourth coxae are evident but like the posterior suture lines of the fourth coxae they become laterally obliterated, Three pairs of lateral glandularia occur on the periphery of the ventral shield. Posterior to the points of insertion of the fourth pair of legs is a single pair of setae. The two pairs of genital acetabula are situated on two oval acetabular plates which are fused with the ventral shield. Each acetabular plate carries three setae. Anterior to the acetabular plates is a pair of glandularia. Two pairs of posterior glandularia flank the slit-like excretory pore. The median pair of posterior glandularia are furnished with two pairs of setae. Between the glandularia on either side lies a small chitinous platelet. Palps (fig. 200) The chaetotaxy of the palp is illustrated in fig. 200. P-11 is dorsally furnished with three heavy setae. P-111 carries two, slender, disto- dorsal setae. P-IV is furnished with one disto-dorsal and two ventral setae. P-V is mucronated and furnished with three claws. Legs (fig. 201) The first leg exhibits the same features as in the adults. I-Leg-5 is elongated with a cluster of ventro-distal setae. I-Leg-6 is short with a deep depression to accommodate the claw and a prominent proximal ventral projection. This makes grasping possible. I-Leg-6 is furnished with long setae. 187 Material Seventeen males, fifty nine females and three nymphs. This material is deposited in the Collection of the Museum of Natural History, Basel, Switzerland. Collection Localities 7, 36, 37, 41, 43 and 45. Discussion This species seems to be one of the most abundant potamophreatic forms in the Jura area. The present nymphs seem to be much younger than the nymph described by Matar & Tanasachi (1946). The dorsal plates are smaller and genital field is not so well demarcated. The lateral indentations of the posterior dorsal shield are more pronounced and the distance between two dor.sal shields is larger. 188 12. FAMILY ARRENURIDAE Thor, 1900 Arrenuridae Thor 1900a:4; K. Viets 1936:401; Cook 1974:41 4 . Diagnostic characters The i diosoma, usually globular but dorso-ventrally flattened in some cases, is heavily sclerotised and completely covered by the dorsal and ventral shields. Dorsum The dorsal shield may be demarcated by the dorsal furrow which may be complete, posteriorly incomplete or completely absent. The dorsal shield, furnished with a variable number of glandularia (usually three pairs), covers most of the dorsal surface area. Occasionally the dorsal shield is greatly reduced, e.g., Arr enurus (MegaZuraca:rus) cey lonicus Daday and A. (Megaluracarus ) egathus Cook. In the males the cauda is usually well developed and can be seen in a dorsal view. The cauda may occasion- ally be incorporated in the dorsal shield. The lateral eyes lie anteriorly beneath the integument. Venter The coxae are usually large and arranged in three groups but they may be fused to form a single group. The median margins of the fourth coxae may vary from being; well developed or they may be reduced to median angles. The fourth coxae are always devoid of glandularia. Numerous genital acetabula are always present. The acetabular plates are definite ridges which may reach latero-dorsally. In the males a well developed posterior cauda may be present. Gnathosoma The gnathosoma is usually short. The palps are typically uncate except in the genus Micruracaropsis. P-V may or may not be medially rotated. 189 Swinnning setae are usually present. Some of the legs of the males may be modified for reproductive purposes. 190 12.1 SUBFAMILY ARRENURINAE Thor, 1900 Arr enurinae Thor 1900a:4; Wolcott 1905:193, 223; Cook 1974:418. Diagnostic characters Idiosoma always more or less globular (not dorso-ventrally flattened). The eyes are situated in raised portions of the integument. The dorsal furrow may be complete, incomplete or absent. The coxae are typically arranged in three groups. The acetabular plates are variable in shape but they are usually laterally expanded. The cauda is occasionally not very well developed in the male. Except in (Mi cr uracaropsi s) the palp is typically uncate. Sexual dimorphism of the legs of the male is not very pronounced but is often present. 12.1. 1 Genus Arrenurus Duges, 1834 Arrenurus Duges, 1834:17; K. Viets 1936:403; Cook 1954:40; 1974:418. Arrenura Hoeven 1835:112 Arr henur us Oken 1836:493, 504 Hydrachna (Arrenurus ) Gervais 1844:202 Anurania Neuman 1880:95 Petiolurus Thor 1900:126 Steganapsi s Wolcott 1901:105 Lacallea Koenike 1910:137 Micrarrenurus Cassagne-Mejean 1966:21 Type species Arrenurus vi ridi s Duges, 1834 Diagnostic characters The dorsal furrow is always present in both sexes but it may, however, be incomplete in males. The medial margins of the fourth coxae are not reduced to angles. Varying degrees are shown in the development of the cauda in the males. The palps are always uncate. P-II may be furnished with a patch of dense setae. 19 1 Ar-renurus (Truncaturus) bowmakeri van Rensburg, 1974 (figs. 202-209) van Rens burg ( 1974). Female (figs. 202-205, plate VIII a, c) Dimensions Length of idiosoma 496 - 533µm; width of idiosoma 490 - 515µm; dorsal length of palp/distal height of palp P-I, 31/31 µm; P-II. 64/64µm; P- I I I , 64/58µm; P-IV, 92/-µm. Dorsum (fig. 202, plate VIII a) The shape of the idiosoma is globular and is dorsally divided by the dorsal furrow into the marginal horseshoe-shaped area and the inner dorsal shield. On the latter are four pairs of setae. The anterior and the lateral pairs of these setae are not associated with glandularia. The lateral pair is situated just posterior to a depression in the integument. The other two pairs of setae,of which one pair is lanceolate, are associated with glandularia. The marginal area is furnished with six pairs of setae of which three pairs are associated with glandularia. Of the latter setae one pair is lanceolate. Postero-laterally the widened termination of the acetabular ridge can be observed. It must be pointed out that it is very difficult to observe the acetabular ridge with the light microscope - even with phase-contrast. The excretory pore is terminally situated and appears to be somewhat dorsal in position. Venter (fig. 205, plate VIII c) Ventrally there is a distinct difference in the sclerotisation of the coxae and the rest of the venter. The anterior two pairs of coxae are fused to f orm a single group but the sutures between the first and second pairs of coxae are clearly visible. The third and fourth pairs of coxae have fused on either side. The sutures between them are, 203 Figs. 202-205; Arrenurus (Trwicaturus) bowmakeri Van Rensburg, 1974, female. · fig. 202, dorsum; fig. · 203, palp; fig. 204, gnathosoma; fi'g. 205, venter. 192 however, clearly visible. The acetabular ridge surrounds the genital pore almost completely and widens laterally and dorsally. The two semicircular genital plates are very large. One pair of setae, with their associated glandularia, is situated between the coxae and the acetabular ridge. Postero-lateral to the acetabular plates are two pairs of setae. Gnathosoma (fig. 204) The ·gnathosoma is typically short and conical. The chelicerae are slender and mucronated. Palps (fig. 203) The chaetotaxy of the palp is illustrated in fig. 203. P-V is typically medially attached to P-IV with the lateral projection of P-IV extending well beyond P-V. The legs are proximally furnished with long spatular setae and the distal joints of the legs carry long flagellar swimming setae. Male (figs. 206-209, plate VIII b, d, e, f) Dimensions Length of idiosoma 558 - 570µm; width of idiosoma 434 - 471µm; dorsal length of palp/distal height of palp P-I, 31/31µm; P-II, 66/64µm; P-III, 54/58µm; P-IV, 83/-µm. Dorsum (fig. 207, plate VIII b, e, f) The idiosoma is oval-shaped. As in the female the dorsum is divided into the marginal horseshoe-shaped area and the inner dorsal shield. This shield , much smaller than that of the female, is actually a depression of the central area (plate VIII b). This area is marked by a smooth 193 transverse band which lacks external ornamentation. Situated in this smooth band are two very large glandularia without associated setae. Posterior to these glandularia there is another pair of approximately the same size but which have a pair of associated setae. Posteriorly the idiosoma is divided into two lobes (plate VIII d, e, f). Dorsally the two lobes surround the petiole (plate VIII e, f). A semi-lunar integument- al ridge flanks the petiole on the right. Two globular structures are situated internally at the base of the petiole. On the relatively broad marginal area are four pairs of setae. The lateral pair is associated with glandularia. On the level of the dorsal depression are the widened terminations of the acetabular ridge. Venter (fig. 208, plate VIII d) The ventral sclerotisation is like that of the female. The anterior two pairs of coxae are fused into a single group. Coxae III and IV are fused on either side but medially well separated. Between coxae II and III there is a pair of glandularia with their associated setae. The acetabular ridge is a transverse band of more or less uniform width. Situated between the posterior coxae and the acetabular ridge is a pair of setae with their associated glandularia. Posterior to the acetabular ridge there are two pairs of setae without glandularia. The slit which partially bisects the idiosoma posteriorly, is visible (fig. 208; plate VIII d). Palps (fig. 206) The chaetotaxy of the palp is illustrated in fig. 206. P-II has four dorsal plumose setae and two slender medial setae. P-III is furnished with two medial setae and one lateral thorn-like seta. P-IV is disto- laterally extended with a flat media-ventral seta. Medially it carries a pair of small setae. P-V, which is medially attached to P-IV, is ventrally furnished with a single slender seta. Figs. 206-209; Arrenurus (Truncaturus) bowmakeri Van Rensburg, 1974, male fig. 206, palp; fig. 207, dorsum; fig. 208, venter; fig. 209, fourth leg. 194 Legs (fig. 209) The chaetotaxy of the fourth leg is illustrated in fig. 209. Characte- ristic are the four very long spatular setae in IV-Leg-2. The fourth and fifth segments of all the legs carry long slender swinnning setae. Material Holotype female, four female paratypes and three male paratypes. The material studied was prepared and mounted in 1969. Hoyer's fluid was used as mountant for permanent preparations. The coverslips were ringed with nail polish. After four years it was found that the preparations had become dehydrated and the Hoyer's fluid crystallised. These preparations proved to be useless for taxonomic study and the material had to be remounted. This time the specimens were mounted in Heinze's modified PVA medium. Unfortunately some of the appendages of the specimens were damaged or lost in the process. The result was that not all the legs were available for study. One female and two male palps were studied before remounting. During the process of remounting most of the setae of the palps broke off. The holotype female, one paratype female and one paratype male will be deposited in the collection of the Department of Zoology, University College of Rhodesia, P.O. Box MP 167, Mnt. Pleasant, Salisbury, Rhodesia. Collection Locality 162 Discussion Due to the heavy sclerotisation of the integument it was almost impossible to determine the precise positions of the setae on the idiosoma with the light microscope. S.E.M. micrographs proved to be invaluable in the study of the chaetotaxy. PLATE VIIl Arrenurus (Truncaturus ) bo~maker i van Rensburg, 1974. a. Dorsum of female b. Dorsum of male c. Venter of female d. Venter of male e. Dorsal view of cauda of male f. Dorsal view of cauda of male PLATE VIII 195 To date only two species of the subgenus have been described from the Ethiopian Region, i.e., A. (Truncarurus) schizopetioZat us Cook 1966 from Liberia and A. (Truncaturus) uncus K.O. Viets 1972 from Rhodesia. A characteristic feature of the present species is the acetabular ridges which reach dorsally. It can be distinguished from A. (T .) s chizopetioZatus by the undivided petiole in the male and the incomplete dorsal furrow in the female. It differs from A. (T.) uncus in having a very narrow medial cleft, the presence of a petiole and the chaetotaxy of the fourth leg. In the female the genital plates are larger and further posteriorly situated than in A. (T.) uncus. p A R T IV 196 13. CHECKLIST OF THE SWISS POTAMOPHREATIC MITES * Species new to the Swiss potamophreatic fauna Superfamily HYDRYPHANTOIDEA Family HYDRYPHANTIDAE Thor, 1900 Subfamily PROTZIINAE Koenike, 1909 Genus PROTZIA Piersig, 1896 *P . eximia (Protz , 18 9 6) Subfamily WANDSIINAE Schwoerbel, 1961 Genus WANDESIA Schechtel, 1912 W. heZvetiaa Walter, 1947 Super family LEBERTOIDEA Family TORRENTICOLIDAE Piersig, 1902 Subfamily TORRENTICOLINAE Monti, 1910 Genus TORRENT I COLA Piersig, 1896 *T . eZZiptiaa Maglio, 1909 *T . jeanneZi (Mota~ & Tanasachi, 1947) *T . unguiauZata (Walter, 1947) Superfamily HYGROBATOIDEA Family HYGROBATIDAE K. Viets, 1930 Subfamily HYGROBATINAE C.L. Koch, 1842 Genus ATRACTIDES C.L. Koch, 1837 *A . aagiaUensis van Rensburg, 1971 *A . cisternarum (K. Viets, 1935) A. dentiauZatus (Walter, 1935) A. firmus (Walter, 1947) *A . gibberipaZpus Piersig, 1898 197 A. "latipalpis (Mota~ & Tanasachi, 1946) A. longus (Walter, 1947) *A . losonensis van Rensburg, 1971 *A . magnipalpis van Rensburg, 1971 *A . micropthalmus (Mota§ & Tanasachi, 1946) *A . nitraensis Laska, 1959 *A . (Po lymegapus) polyporus (K. Viets, 1922) *A . primitivus (Walter, 1947) A. simiiis (Angelier, 1949) *A . szalayi (Mota~ & Tanasachi, 1948) Family FELTRIIDAE K. Viets, 1926 Genus FELTRIA Koenike, 1892 *F . (FeUrieUa) airo lo ens is van Rensburg, 1971 F. (?) disjuncta Walter, 1947 *F . cor>nuta paucipor>a Szalay, 1946 *F . fossea van Rensburg, 1971 *F . golatensis van Rensburg, 1971 F. subterranea stygophil,a Walter, 1947 F. (A zugo f el, tria ) insoUta (Walter, 1947) Family ATURIDAE Thor, 1900 Subfamily FR0NTIP0D0PSINAE K. Viets, 1931 Genus FR0NTIP0D0PSIS Walter, 1919 F. reticulatifr ons Szalay, 1945 Subfamily AX0N0PSINAE K. Viets, 1929 Genus ALBAX0NA Piersig, 1893 A. minuta Szalay, 1944 198 Genus LJANIA Thor, 1898 *L . bipapiLLata bipapiLLata Thor, 1898 L. procera Walter, 1947 L. subtiiis Walter, 1947 Genus LETHAXONA K. Viets, 1932 L. cavifrons Szalay, 1943 L. pygmaea K. Viets, 1932 Subfamily ATURINAE Wolcott, 1905 Genus ATURUS Kramer, 1895 *A . C!Y'initus Thor, 1902 *A . Lelgioensis van Rensburg, 1971 A. pauciporus Walter, 1947 Genus KONGSBERGIA Thor, 1898 K. angusta Walter, 1947 K. caUosa Walter, 1947 K. dentata Walter, 1947 K. f usi f or>mes Walter, 1947 K. pectinata Walter, 1947 K. r>ut tner i Walter, 1930 K. simiUs K. Viets, 1939 K. simplicipes Walter, 1947 Super family ARRENUROIDEA Family MOMONIIDAE Lundblad, 1930 Sub f amily STYGOMOMONIINAE Motaj & Tanasachi, 1946 Genus STYGOMOMONIA Szalay, 1934 s. Latipes Szalay, 1943 199 Family NEOACARIDAE Mota~ & Tanasachi, 1947 Genus NEOACARUS Halbert, 1944 N. hibernicus Halbert, 1944 Family CHAPPUISIDIDAE Mota~ & Tanasachi, 1946 Subfamily CHAPPUISIDINAE Mota~ & Tanasachi, 1946 Genus CHAPPUIS IDES Szalay, 1943 C. eUipticus Walter, 1947 Family ATHIENEMANNIIDAE Lundblad, 1930 Subfamily ATHIENEMANI INAE K. Viets, 1922 Genus STYGOHYDRACARUS K. Viets, 1932 s. subterraneus Walter, 1947 200 14. THE ETHIOPIAN REGION AND THE DISTRIBUTION OF THE ETHIOPIAN WATER MITES The Ethiopian Region (fig. 210) comprises Yemen, South Yemen, Oman and Saudi Arabia south of the Tropic of Cancer as well as the African Continent south pf the Tropic of Cancer. Also included in this region is the Island of Madagascar, but not the Azores, Madeira or Canary Islands. Karl Viets (1953) published a catalogue of all the African water mites and this catalogue was updated by Kurt 0. Viets (1971). These two extensive works contain the relevant taxonomic information on African water mites up to 1970. They deal with the distribution, habitat and most important, with the synonomy of the different species. Since the publication of the above-mentioned papers, many political changes have taken place on the African continent and the borders between various countries have been changed. A map of Africa (fig. 210) with the latest names of the countries is included. In the checklist the old names of the countries have been substituted by the new. The Ethiopian Region is a fairly well isolated geographical area, bounded by the Sahara and the Indian and Atlantic Oceans. It might be expected that the Hydrachnellae, being restricted to freshwater, would be unable to cross barriers like the dry Sahara Desert and the oceans surrounding the region. Consequently one might expect most of the species to be endemic. From the records available this ,~as indeed found to be the case. Of all 69~ species recorded from the Ethiopian Region only 17 occur beyond its boundaries. The Ethiopian species therefore constitute a' geographically and faunistically restricted group of water mites. For this reason the non-Ethiopian (African) species (i.e., those species occurring north of the Tropic of Cancer) have been omitted from this list. Our knowledge of the distribution pattern of mites in the Ethiopian Region is incomplete. The most intensive collecting has been done in Cameroon, Ivory Coast, Kenya, Liberia, Madagascar, Mozambique, Rhodesia, .., "'r' mTn PALEARCT IC r::':7 ETHIOPIAN . LdREGION lilLL.1 REGION ,.:-~--,.;-:~~"7""'-:--:':,!,c,;,;;,.:..1/ ZIDAR 0 210 Fig. 210; The Ethiopian Region. 201 South Africa, Tanzania and Zaire. Records are available of a few species from countries like Senegal, Zambia, Gabon, Ghana, Angola, and Malawi. Virtually nothing is known about the water mite fauna of Botswana, Lesotho, Swaziland, Mali, Nigeria and Niger. Twenty-three of the fourty-four water mite families listed by Cook (1974) are represented in the Ethiopian region. The subfamily Pollicipalpinae have been recorded only from this region. To date, representatives of the following genera have been recorded only from the Ethiopian Region: Heterothyas, Placothyas, Teratothyasides , Mamersopsides , Anisitsidax'tia, Gilatonia, Africoxus, Tubophora , Pter olimnesia, Me sobatella, Hygrobatopsis , Tetrabates , Ambiguobates , Ambiguobatella, Plesiohygrobates, Africacarus, Heterata.x , Pionatax, Nyangalla, Esekalla, Kax'lvietsia, Axonopsalbia, Pseudaxonopsalbia, Suba.xonopsalbia, Neoa.xonopsalbia , Javalbiella, Bax'ba.xona , Neobax'ba.xona, Storma.xonella , Subaturus , Mideopsellides , Thoracophoracax'us , Hamappendix , Allax'renurus and Eupatrella. 202 15. CHECKLIST OF THE ETHIOPIAN WATER MITES Super family HYDROVOLZIOIDEA Family HYDROVOLZIIDAE Thor, 1905 Subfamily HYDROVOLZIINAE Thor, 1905 Genus HYDROVOLZ IELLA (K . Viets, 1935) H. Zata Walter, 1935 Di str: Ivory Coast Super family HYDRACHNOIDEA Family HYDRACHNIDAE Leach, 1815 Genus HYDRACHNA H. (? Anohydrachna) fi ssigera Koenike, 1895 Distr: Madagascar, Sudan H. (Rhabdohydrachna) bisignifera K. Viets, 1913 bisignifera Distr : Tanzania H. (Rhabdohydrachna ) bisignifera Lundblad, 1933 worthingtoni Di s tr: Uganda H. (Rhabdohydrachna) murati Walter, 19 39 Distr: Chad H. (Rhabdohydrachna) signata Koenike, 1898 Di s tr: Kenya, Madagascar, Tanzania, Cameroon H. (Rhabdohydrachna) spinosa Koenike, 1893 Distr: S. Africa, Zaire, Zanzibar H. (Rhabdohydrachna) spinosa Walter, 1931 spinosa subtilis Distr: Tanzania, Ethiopia, Ivory Coast, Zaire H. (Diplohydrachna) madagascariensis Lundblad, 1946 Distr : Madagas car H. (? Diplohydrachna) perp lexa Cook, 1966 Distr: Liberia H. (Diplohydrachna) prop~nqua Koenike, 1898 Distr: Madagascar H. (Hydrachna ) amp lexa Koenike , 1898 Distr: Madagascar 20 3 H. (Hydrachna) dartvellei Walter, 1939 Distr: S. Africa, Zaire H. (Hydrachna) inaequiscutata Lundblad, 1933 Distr: Uganda, Sudan H. (Hydrachna) kenyensis Lundblad, 1942 Distr: Kenya, S. Africa H. (Hydrachna) dilatata Daday, 1898 Distr: Sudan?, Ceylon H. (Hydrachna) eldoretica Lundblad, 192 7 Distr: Kenya, Ethiopia, Ivory Coast H. (Scutohydrachna) clavipalpis Lundblad, 1949 Distr: Zaire H. (Scutohydrachna) junodi junodi Walter, 1924 Distr: Mozambique H. (Scutohydrachna) junodi abyssinica Lombardini, 1941 Distr: Ethiopia H. (Bargena) rrririfica Koenike, 1893 Distr: S. Africa, Uganda, Zanzibar, Zaire, Cameroon, Kenya H. spec . K.O. Viets, 1964 Distr: S. Africa Superfamily EYLAOIDEA Family LIMNOCHARIDAE Grube, 1859 Subfamily LIMNOCHARINAE Grube, 1859 Genus LIMNOCHARES Latreille, 1796 L. (Cyclothrix) crinita Koenike, 189 8 Distr: S. Africa, Zaire, Liberia, Nossi Be, Madagascar L. (Lirnnochares) expansipalpis Cook, 1966 Distr: Liberia Genus NEOLIMNOCHARES Lundblad, 1937 N. africana Cook, 1966 Distr: Liberia N. p lacophore l la Cook, 1966 Distr: Liberia N. tenuiscutata (K. Viets, 1914) Distr: Madagascar, S. Africa 204 Family EYLAIDAE Leach, 1815 Genus EYLAIS Latreille, 1796 E. (Proteylais) degenerata (Koenike, 189 7) Distr: Southern Europe, Asia, Africa E. (?) crassipalpis Thor, 1902 Distr: S. Africa E. (Pareylais) rimosa Piersig, 1899 Distr: Morocco, Algeria, Tunisia, Ethiopia, Europe, Asia E. (Pareylais) crenocula Koenike, 189 7 Distr: Tanzania, Kenya, Ivory Coast, Liberia, S. Africa, Mozambique E. (?) lightfooti (Thor, 1902) Distr: S. Africa E. (?) megalostoma megalostoma (Koenike, 1897) Distr: Aldabra, Tanzania, Morocco, Algeria, Tunisia E. (?) paski Soar & Williamson, Distr: Zambia 1927 E. (?) puree U i Thor, 1902 Distr: S. Africa E. (?) tor1•en tico la Walter & Bader, Distr: Kentya 1952 E. (?) voeltzkowi Koenike, 189 7 Distr: Madagascar, s. Africa, Sudan E. (?) spec. K.O. Viets, 1964 Distr: Mada.gas car Super family HYDRYPHANTOLOEA Family HYDRYPHANTIDAE Thor, 1900 Subfamily HYDRYPHANTINAE Piersig, 1896 Genus HYDRYPHANTES Koch, 1841 H. ( Hydryphan tes) pe itatus Walter, 1925 Distr: Algeria, Zaire H. (Octohycb:ryphantes) octoporus (Koenike, 1896) Dis tr: Zai1:-e ,, Europe, Asia H. (Papi i lopor·•us) incertus (Koenike, 189 3) Dis tr: Af·cica 205 Subfamily THYASINAE (K. Viets, 1926) Genus TRICHOTHYAS K. Viets, 1926 T. (Trichothyas) pennata K. Viets, 1913 Distr: Cameroon T. (Lundhladia) cunctans (Lundblad, 1951) Distr: Kenya T. (Plesiothyas) multipora (Walter, 1953) Distr: Ivory Coast Genus HETEROTHYAS Lundblad, 1941 H. africana Lundblad, 194 1 Distr: S. Africa Genus PLACOTHYAS Lundblad, 1926 P. (Placothyas) octopora (K. Viets, 1914) Distr: S. Africa P. (Octothyas) hewittae Lundblad, 1945 Distr: S. Africa Subfamily DIPLODONTINAE K. Viets, 1936 Genus DIPLODONTUS Duges, 1833? D. opimus Koenike, 1896 Distr: Madagascar D. schaubi Koenike, 1893 Distr: Africa D. schaubi gracilirostris Lundblad, 1942 Distr: Kenya Subfamily MAMERSINAE K. Viets, 1931 Genus MAMERSA Koenike, 1893 M. dividua Bader, 1964 Distr: Tanzania M. testudinata Koenike, 1898 Distr: Madagascar, Mozambique, Cameroon, Uganda Family HYDRODROMIDAE K. Viets, 1936 Genus HYDRODROMA Koch, 1837 H. capensis K. Viets, 1914 Distr: S. Africa, Madagascar, Central Sahara, Zaire, Kenya 206 H. despiciens Muller, 1776 Distr: Africa, Europe, Asia, America H. liberiensis Cook, 1966 Distr: Liberia H. perreptans perreptans K. Viets, 1913 Distr: Cameroon, Liberia H. perreptans ocellata Walter & Bader, Distr: Kenya 1952 H. trigonometr ica Walter, 1928 Distr: Algeria, Cameroon Genus OXOPSIS Nordenski old, 1905 0 . diplodontoides Nordenskiold, 1905 Distr: Sudan Family TERATOTHYASIDAE (K. Viets, 1929) Genus . TERATOTHYASIDES Lundblad, 1941 T. (Teratothyasides) clathr atus Lundblad, 1941 Distr: Uganda, Tanzania T. (Teratothyasides) lundhladi Cook, 1966 Distr: Liberia T. (Hansvietsia ) reticulatus Schoonbee, 1959 Distr: S. Africa T. (Hansvietsia ) sagariphor us Cook, 1966 Distr: Liberia T. (Hansvietsia ) sempiterna K. Vie ts, 1951 Distr: S. Africa, Liberia, Sahara Central T. (Hans vietsia) undu latus Cook, 1966 Distr: Liberia T. (Rhynchohansvietsia ) congoens~s K.O. Viets & Distr: Zaire Bottger, 1974 Super family LEBER TO IDEA Family SPERCHONIDAE (Thor, 1900) Subfamily SPERCHONINAE (Thor, 1900) Genus SPERCHON Kramer, 1877 S . (Sperchon ) inusitatus Walter & Bader Distr: Kenya 1952 207 S. (Mixosperchon) echinodermus Lundblad, 1951 Distr: Kenya S. (Mixosperchon) edentulus Lundblad, 1951 Distr: Kenya, Zaire S. (Mixosperchon) fenestratus Lundblad, 192 7 Distr: Kenya, Tanzania, S. Africa, Zaire S. (Mixosperchon) gracilis Lundblad, 1951 Distr: Kenya, S. Africa, Uganda S. (Mixosperchon) lamellipes Lundblad, 1951 Distr: Kenya, Zaire S. (Mixosperchon) mo~tigena Lundblad, 1951 Distr: Uganda S. (Mixosperchon) papilliferus Lundblad, 1941 Distr: Kenya S. (Mixosperchon) plumisetus plumisetus Lundblad, 1951 Distr: Kenya, Tanzania S. (Mixosperchon) plumisetus sublaevis Lundblad, 1951 Distr: Kenya S. (Mixosperchon) robustus K.O. Viets, 1970 Distr: Rhodesia S. (Mixosperchon) soar-i Lundblad, 1952 Distr: Uganda S. (Mixosperchon) vicarius Lundblad, 1951 Distr: Uganda S. (Hispidosperchon) aberrans aberrans K. Viets, 1956 Distr: S. Africa S. (Hispidosperchon) aberrans K.O. Viets, 1962 poUiciger Distr: S. Africa S. (Hispidosperchon) africanus Lundblad, 1951 Distr: Kenya, Zaire S. (Hispodosperchon) biscutatus Lundblad, 1941 Distr: Kenya, S. Africa, Zaire S. (Hispidosperchon) centrotus Lundblad, 1951 Distr: Kenya S. (Hispidosperchon) circumcinctus Lundblad, 1951 Distr: Kenya, S. Africa, Zaire 208 s. (Hispidosperchon) directus K. Viets, 1956 Distr: s. Africa s. (Hispidosperchon ) elgonensis Lundblad, 1927 Distr: Kenya s. (Hispidosperchon) pos tocularius K. Viets, 1956 Distr: s. Africa s. (Hispidosperchon) variabilis Lundblad, 1951 Distr: Kenya s. (Hi spidosperchon) variabilis ovalis Lundblad, 1952 Distr: Tanzania S. (Hispidosperchon) variabilis K. Viets, 1955 tenuistriatus Distr: Kenya Family ANISITSIELLIDAE Koenike, 1910 Subfamily ANISITSIELLINAE Koenike, 19 10 Genus MAMERSOPSIS Nordenskiold, 1905 M. circumclusa K. Viets, 1914 Distr: Cameroon M. thoracica Nordenskiold, 1905 Distr: Sudan Genus PLATYMAMERSOPSIS K. Viets, 1914 P. cooki K.O. Viets, 1970 Distr: Rhodesia P. crassipes Cook, 1966 Distr: Liberia P. liberiensis Cook, 1966 Distr: Liberia P. nordenskioldi K. Viets, 1914 Distr: Liberia, Cameroon P. ovalis Cook, 1966 Distr: Liberia P. sirrrilis Cook, I 966 Distr: Liberia P. vietsi Cook, 1966 Distr: Liberia Genus MAMERSOPS!:DES K. Viets, 1916 209 M. sigthori K. Viets, 1916 Distr: Cameroon M. vietsi Cook, 1966 Distr: Liber i a Genus SIGTHORIA (Nordenskiold, 1905) S. nilotica (Nordenskiold, 1905) Distr: Uganda, Sudan, Kenya, Liberia Genus MAMERSELLA K. Viets, 1929 M. (NeomamerseLLa) tototaensis Cook, 1966 Distr: Liberia, Zaire Genus ANISITSIDARTIA Cook, 1966 A. micr opalpis Cook, 1966 Distr: Liberia, Zaire Genus GILATONIA K.O. Viets & Bottger, 1974 G. triscutata K.O. Viets & Distr: Zaire Bottger, 1974 Subfamily NILOTONIINAE K. Viets, 1929 Genus MANOTONIA (Walter, 1935) M. mus ci cofo (Walter, 1935) Distr: Ivory Coast Genus NILOTONIA Thor, 1905 N. (Ni l otonia) gracili palpi s (Lundblad, 1941) Distr: Ethiopia N. (Ni l otonia ) Loricata (Nordenskiold, 1905) Distr: Sudan, Tanzania, Zaire, Uganda N. (Nilotonia) micropora (Walter, 1939) Distr: Zaire N. (Nilotonia ) r obus ta robus ta (Walter, 1931) Distr: Kenya, Zaire, Sahara Central N. (Nilotonia ) robusta i nflata (Walter, 1935) Distr: Ivory Coast N. (Ni l otonia ) s cutata Cook, 1966 Distr: Liberia N. (Nilotonia) tes tudinata Cook, 1966 Distr: Liberia 2 10 N. (Nilotonia ) thermophila (Lundblad, 1951) Distr: Uganda N. (Nilotonia) violacea (Lundblad, 1951) Distr: Kenya N. (Dartia) catarrhacta (Lundblad, 1941) Distr: S. Africa Family LEBERTIIDAE Thor, 1900 Genus LEBERTIA (Lebert, 1879) L. (Pilolebertia) capens~s K. Viets, 1956 Distr: S. Africa L. (Pilolebertia) spec . K.0. Viets, 1964 Distr: S. Africa L. (Pseudolebertia) liberiensis Cook, 1966 Distr: Liberia L. (Pseudolebertia) spec. Lundblad, 1952 Distr: Tanzania Family OXIDAE K. Viets, 1926 Genus AFRICOXUS Cook, 1966 A. (Africoxus) consobrinus (Lundblad, 1952) Distr: Kenya A. (Africoxus) curvisetus (K. Viets, 1916) Distr: Zaire, Liberia, Cameroon A. (Africoxus) saskai (Lundblad, 1942) Distr: Ethiopia A. (Pseudofrontipoda) dentipes (Lundblad, 1924) Distr: Ethiopia A. (Pseudofrontipoda ) obesus Cook, 1966 Distr: Liberia A. (Pseudofrontipoda) szalayi Cook, 1966 Distr: Liberia Genus FRONTIPODA Koenike, 189 1 F. biscutata Cook, 1966 Distr: Liberia F. calicipeltata K. Viets, 1956 Distr: S. Africa 211 F. lundb ladi Cook, 1966 Distr: Liberia F. oxoidea K. Viets, 1911 Distr: Cameroon, Fernando Pao, Liberia Genus OXUS Kramer, 1877 O. (Oxus) maglioi K. Viets, 1913 Distr: Zaire, Liberia, Cameroon O. (Oxus) stuhlmanni (Koenike, 1895) Distr: Kenya, S. Africa, Ivory Coast, Zaire, Angola, Cameroon, Tanzania, Liberia Family TORRENTICOLIDAE Piers ig, 1902 Subfamily TORRENTICOLINAE Piersig, 1902 Genus TORRENTICOLA Piersig, 1896 T. (Torrenticola) anomalella Cook, 1966 Distr: Liberia, Zaire T. (Torrenticola) aduncipalpis Lundblad, 1951 Distr: Uganda T. (Torrenticola) binga K.0. Viets, 1970 Distr: Rhodesia T. (Torrenticola) bomiensis Cook, 1966 Distr: Liberia T. (Torrenticola) bituberosa (K. Viets, 1916) Distr: Cameroon T. (Torrenticola) bryki Lundblad, 1927 Distr: Kenya, Zaire T. (Torrenticola) darrikohleri (K. Viets, 1911) Distr: Cameroon, Fernando Pao T. (Torrenticola) disjuncta Lundblad, 1951 Distr: Kenya T. (Torrenticola) eurystoma K, Viets, 1956 Distr: S. Africa T. (Torrenticola) faciata (K. Viets, 1916) Distr: Kenya, Liberia, Ethiopia, Cameroon T. (Torrenticola) gracilis (Walter & Bader Distr: Kenya, Ethiopia 1952) 2 12 T. (Torrenticola) harrisoni K. Viets, 1956 Distr: S. Africa, Ethiopia, Rhodesia, Zaire T. (Torrenticola ) ima K.O. Viets & Distr: Zaire Bottger, 1974 T. (Torrenticola ) loda Cook, 1966 Distr: Liberia T. (Torrenticola ) magnivalvaris Walter & Bader, Distr: Madagascar 1953 T. (Torrenticola ) marginata (Walter, 1926) Distr: Madagascar, Zaire T. (Torrenticola ) motasi Cook, 1966 Distr: Liberia T. (Torrenticola) obtusidens (Lundblad, 1951) Distr: Kenya T. (Torr enticola ) procera K.O. Viets, 1965 Distr: S. Africa T. (Torrenticola ) proxima Lundblad, 1951 Distr: Uganda, Zaire T. (Torrenticola ) rhodesiensis K.O. Viets, 1970 Distr: Rhodesia T. (Torrenticola ) serratipalpis (K. Viets, 1913) serratipalpis Distr: Zaire, Ethiop ia, Cameroon, T. (Torrenticola) serrati palpi s holmi (Lundblad, 1941) Distr: Kenya T. (Torrenticola ) serratipalpis Cook, 1966 liberiens is Distr: Liberia T. (Torrenticola ) solitaria K.O. Viets & Distr: Zaire Bottger, 1974 T. (Torrenticola ) violacea K.O. Viets, 1972 Distr: S. Africa T. (Torrenticola ) spec . K.O. Viets, 1972 Distr: Rhodesia T. (Monatractides ) acutiscutata (K. Viets, 1913) Distr: Cameroon T. (Monatractides) amota K.O. Viets & Di s tr: Zaire Bottger, 1974 2 13 T. (Monatr actides) amplipalpi s Lundblad, 1951 Distr: Kenya, Zaire, Uganda T. (Monatr actides) angulosa K.O. Viets & Distr: Zaire Bottger, 1974 T. (Monatractides) capensi s K. Viets, 1956 Distr: S. Africa, Zaire T. (Monatr actides) congoensis K.O. Viets & Distr: Zaire Bottger, 1974 T. (Monatr actides) consi mi lis K.O. Viets & Distr: Zaire Bottger, 1974 T. (Monat r actides) convexiscutata K. Viets, 1958 Distr: Cameroon, Liberia T. (Monatractides) corni palpis Cook, 1966 Distr: Liberia T. (Monatr actides) crassi seta Cook, 1966 Distr: Liberia T. (Monatr actides) cris tata (K. Viets, 1916) Distr: Cameroon, Liberia T. (Monatractides) diver gens Cook, 1966 Distr: Liberia T. (Monatr actides) dolichosoma Cook, 1966 Distr: Liberia T. (Monatr actides) extensa Bader, 1968 Distr: Zaire T. (Monatr actides) f alci f era K.O. Viets & Distr: Zaire Bottger, 1974 T. (Monatr actides) fi ssa Lundblad, 1942 Distr: Ethiopia, Algeria T. (Monatractides) intermedi a Cook, 1966 Distr: Liberia T. (Monatr actides) jucu.nda (Lundblad, 192 7) Distr: Kenya, Zaire, Ethiopia, Tanzania T. (Monat ractides) koenikei (K. Viets, 1916) Distr: Liberia, Cameroon T. (Monat r actides) longicoxalis Cook, 1966 Dis tr: Liber.ia 214 T. (Monatr actides) marshaZZae Cook, 1966 Distr: Liberia T. (Monatractides) marye ZZenae Cook, 1966 Distr: Liberia T. (Monatr actides) media K.0. Viets, 1970 Distr: Rhodesia T. (Monatractides) micros t oma Koenike, 1898 Distr: Liberia, Cameroon, Rhodesia, Tanzania T. (Monatractides ) mitcheUi K.0. Viets, 1965 Distr: s. Africa T. (Monatractides ) neosti geophor a Cook, 1966 Distr: Liberia T. (Monatractides) opi mipa lpi s K.0. Viets & Distr: Zaire Bottger, 1974 T. (Monartactides) ovata K.0. Viets, 1970 Distr: Rhodesia T. (Monatractides) pinguipaZpi s Cook, 1966 Distr: Liberia T. (Monatract ides) procursa K.0. Viets & Distr: Zaire Bottger, 1974 T. (Monatractides) pusi Ua (K. Viets, 1925) Distr: Cameroon T. (Monatractides) r i vaUs K.O. Viets & Distr: Zaire Bottger, 1974 T. (Monatractides) rubi cunda K. Viets, 1956 Distr: s. Africa T. (Mona t ractides) s tarmuhZneri K.O. Viets, 1964 Distr: Madagascar T. (Monatractides) s tigeophora Cook, 1966 Distr: Liber i a T. (Monatractides) tinka K.O. Viets & Distr: Zaire Bottger, 1974 T. (Monatractide s) uniscutata (K. Viets, 1925) Distr: Cameroon T. (Mona t ractides) ventriosa ventriosa (K. Viets, 1916) Distr: Kenya, Zaire, Cameroon S. Africa, Liberia, Uganda, Fernando Poo 215 T. (Monatractides) ventriosa (Lundblad, 1941) stenostomoides Distr: Kenya, S. Africa T. (Monatractides) venu.sta africana Cook, 1966 Distr: Liberia T. (Monatractides) spec. K.O. Viets & Distr: Zaire Bottger, 1974. T. (?) spec. K.O. Viets, 1965 Distr: S. Africa Genus PSEUDOTORRENTICOLA Walter, 1906 P. MitcheUi (Cook, 1966) Distr: Liberia Superfamily HYGROBATOIDEA Family PONTARACHNIDAE Koenike, 1910 Genus PONTARACHNA Philippi, 1840 P. capensis Lohmann, 190 7 Distr: S. Africa P. punctulwn Philippi, 1840 Distr: Red Sea, S. Africa Family LIMNESIIDAE Thor, 1900 Subfamily LIMNESIINAE Koenike, 1909 Genus TUBOPHORA Walter, 1935 T. limnesioides Walter, 1935 Distr: Ivory Coast Genus PTEROLIMNESIA (K. Viets, 1942) P. armata Koenike, 1895 Distr: Tanzania P. conjuncta Walter, 1935 Distr: Upper Volta Genus LIMNESIA C,L. Koch, 1836 L. (Limnesia) africana Thor, 1902 Distr: S. Africa, Kenya L. (Limnesia) aspera Koenike, 1898 Distr: Madagascar, Nessi Be L. (Limnesia) breindl,,i Halik, 1944 Distr: Zaire 216 L. (Limnesia) campanulata Koenike, ,t 895 Distr: Tanzania, Cameroon, Ivory Coast, Fernando Poo, Zaire, Zambia, S. Africa L. (Limnesia) foquellensis Cook, 1966 Distr: Liberia L. (Limnesia) graciliseta Viets, 1956 Distr: S. Africa L. (Limnesia) lacustris K.O. Viets, 1973 Distr: Zaire L. (Limnesia) longidens longidens Lundblad, 1949 Distr: Zaire L. (Limnesia) longidens magnipora Cook, 1966 Distr: Liberia L. (Limnesia) lucifera Koenike, 1898 Distr: numerous localities in Africa L. (Limnesia) mucronata K.O. Viets, 1964 Distr: S. Africa L. (Limnesia) paracampanulata Cook, 1966 Distr: Liberia L. (Limnesia) resupinata K. Viets, 1956 Distr: S. Africa L. (Limnesia) rugosa Walter, 1931 Distr: Kenya, Uganda, Ethiopia L. (Limnesia) scutellata Koenike, 1898 Distr: Madagascar, Sudan, Kenya L. (Limnesia) separata Cook, 1966 Distr: Liberia L. (Limnesia) sokolowi Cook, 1966 Distr: Liberia L. (Limnesia) subcampanulata Cook, 1966 Distr: Liberia L. (Li mnesia) undulata (Muller, 1776) Distr: S. Africa, Europe, Asia, America L. (Limnesia) walteri Migot, 1926 Distr: Algeria, Tunisia, Sahara Central, Ivory Coast, Mozambique, Mauritania, Europe 217 L. (Tetralimne sia ) aspera Koenike, 1898 Distr: Madagascar, Nossi Be L. (Tetralimnesia) macropora K. Viets, 1921 macropora Distr: Tanzania, Kenya, Sudan, Zaire, Angola, Ivory Coast, Madagascar, Sahara Central L. (Tetralimnesia ) maglioi Cook, 1966 Distr: Liber i a L. (Tetralimnesia ) macr opor a naias Lundblad, 1951 Distr: Kenya L. (Tetralimnesia ) monodi monodi Walter, 1946 Distr: S. Africa, Mauritania, Kenya, Zaire L. (Tetra i imnesia) monodi plwrrise t us Bader & van Distr: s. Africa Rens burg, 1968 L. (Te tralimnesia ) monodi processifer a Lundblad, 1949 Distr: Zaire, Kenya L. (Duralimnesia) shOJ.Ji Cook, 1966 Distr: Liberia L. (Duralimnesia ) tenuipalpi s (K. Viets, 1924) Distr: Cameroon, Ivory Coast L. (Duralimnesia ) testudinata Cook, 1966 Distr: Liberia L. (? ) crassipalpis Walter, 19 35 Distr: Ivory Coast Family HYGROBATIDAE Koch, 1842 Subfamily HYGROBATINAE Koch, 1842 Genus HYGROBATES Koch, 1837 H. (Hygrobates ) acutidens K. Vi ets, 1956 Distr: S. Africa H. (Hygrobates ) baderi K. Viets, 1955 Di str: Kenya? H. (Hygrobates ) chutteri K.O. Viets, 1963 Distr: S. Africa H. (Hygrobates) damasi Lundblad, 1949 Distr: Zaire 218 H. (Hygrobates) edentipalpis Soar, 1910 Distr: Zambia, Zaire H. (Hygrobates) elgonensis Lundblad, 192 7 elgonensis Distr: Tanzania, Kenya H. (Hygrobates) elgonensis capensi s K. Viets, 1956 Distr: S. Africa H. (Hygrobates) elgonensis Lundblad, 1952 ki Zimandjaricus Distr: Tanzania H. (Hygrobates) extensus K. Viets, 1924 Distr: Cameroon H. (Hygrobates) falcilaminatus Walter, 1926 Distr: Morocco, Ivory Coast, Europe H. (Hygrobates ) inflatus K. Viets, 1925 Distr: Cameroon H. (Hygrobates) Zaceratus Lundblad, 1927 Distr: Ethiopia, Kenya, Ivory Coast, S. Africa H. (Hygrobates) Ziberiensis Cook, 1966 Distr: Liberia H. (Hygrobates) Zatilimbates Mota~, 1932 Distr: Madagascar H. (Hygrobates) marlieri Bader, 1956 Distr: Zaire H. (Hygrobates) nilotocus Walter, 1922 Distr: Sudan H. (Hygrobates) nodosus K.O. Viets, 1971 Distr: Rhodesia H. (Hygrobates) papiZZophorus Cook, 1966 Distr: Liberia H. (Hygrobates) sanguineus sa:nguineus K. Viets, 1956 Distr: S. Africa H. (Hygrobates) sa:nguineus K.O. Viets, 1968 transvaalensis Distr: S. Africa H. (Hygrobates) segregatus K.O. Viets, 1968 Distr: S. Africa 2 19 H. (Hygrobates ) sigthori sigthori K. Viets, 1914 Distr: S. Africa H. (Hygrobates) sigthori rubicundus K. Viets, 1956 Distr: S. Af rica H. (Hygrobates ) soari K. Vi e ts , 191 1 Distr: numerous localities H. (Hygrobates ) sudafricanus K.O. Viets, 1963 Distr: S. Af rica H. (Hygrobates ) terrrrinalis Bader, 1968 Distr: Zaire H. (Capobates) sarsi Thor, 1898 Distr: S. Africa H. (Thonia) loveni Lundblad, 192 7 Distr: Kenya H. (Hygrobatomegapus) spathuli f erus Lundblad, 192 7 spathuliferus Distr: Kenya , Tanzania, Zaire H. (Hygrobatomegapus) spathuliferus Lundblad, 1952 coriaceus Distr: S. Africa, Uganda H. (Scutobates) ovalis Cook, 1966 Distr: Liberia H. (Monobates) chappuis i Walter, 1935 Distr: Ivory Coast, Kenya, Zaire, Liberi a H. (Decabates) angelieri Cook, 1966 Distr: Liberia Genus MESOBATELLA K. Viets, 1931 M. serratiseta (K. Viets, 1916) Distr: Cameroon Genus ATRACTIDES Koch, 1937 A. (Atractides ) abruptus Cook, 1966 Dis tr : Liberia A. (Atractides) africanus (Lundblad, 195 1) Distr: Kenya A. (Atr actides ) assirrrilis K.O. Viets, 1964 Distr: S. Africa 220 A. (A t r actides) baderi K. Viets, 1956 Distr: Kenya A. (Atractides ) callosus K.O. Viets, 1972 Distr: Rhodesia A . (Atractides ) contemptus (Lundblad, 1951) Distr: Ethiopia, Uganda A. (Atractide s) coriacellus K. Viets, 1956 Distr: S. Africa A. (At r actides ) damkohleri (K. Viets, 1916) Distr: Cameroon, Kenya, Uganda, Tanza~ia, Liberia, S. Africa A. (Atractides) enguus Lundblad, 1952 Distr: Uganda A. (A tractides ) falcipe s (Walter & Bader Distr: Kenya 1952) A. (A t r actides) harrisoni K.O. Viets, 1970 Distr: Rhodesia A. (Atractides ) immodes tus (Walter & Bader, Distr: Kenya 1952) A. (Atractides ) invidendus K.O. Viets, 1964 Distr: S. Africa A. (Atractides ) kilimandjaricus Lundblad, 1952 Distr: Tanzania A. (Atractides ) kuhlmanni K.O. Viets, 1963 Distr: S. Africa A. (A t r actides ) kuhnei (K. Viets, 1911) Distr: Cameroon A. (Atractides ) latisetus (K. Viets, 1916) Distr: Kenya, Uganda, S. Africa, Liberia A. (Atractides ) levipalpis Bader, 1968 Distr: Zaire A. (Atractides) linearis (Lundblad, 1927) Distr: Kenya, Tanzania, S. Africa A. (Atractides ) lundbladi lundbla,di (Ha l ik, 1947) Distr: Tanzania A. (Atractides ) l undbladi curvitarsis K. Viets, 1955 Distr: Kenya 221 A. (Atractides) madagascariensi s K.O. Viets, 1964 Distr: Madagascar A. (Atractides) neotes tudo Cook, 1966 Distr: Liberia A. (Atractides) parates tudo Cook, 1966 Distr: Liberia A. (Atractides) processifer us (Walter & Bader, Distr: Kenya 1952) A. (Atractides) pseudotes tudo Cook, 1966 Distr: Liberia A. (Atractides) pulcher K. Viets, 1956 Distr: S. Africa A. (Atractides) pusiZZus (Walter & Bader, Distr: Kenya 1952) A. (Atr actides ) rosteZZatus K.O. Viets, 1964 Distr: S. Africa A. (Atractides) scuteZZi f er us K.O. Vi ets, 1964 Distr: S. Afr i ca A. (Atr actides ) scuti f er (Lundblad, 1951) Distr: Uganda, S. Africa A. (Atractides) splendidus sp lendidus (Lundblad, 1927) Distr: Kenya, Uganda, Zaire A. (Atractides ) sp lendidus superbus (Lundblad, 1927) Distr: Kenya, Uganda A. (Atractides) subtes tudo Cook, 1966 Distr: Liberia A. (Atr actides ) sudafricanus K. Viets, 1956 Distr: S. Africa A. (Atr actides) tenuipes Lundblad, 1952 Distr: Kenya A. (Atractides) tenuipes anuJiguus K.O. Viets, 1970 Distr: Rhodesia A. (Atractides) testudo Cook, 1966 Distr: Liberia A. (Atractides ) thoracatus Koenike, 1898 Distr: Nossi Be, S. Africa A. (Atractides) t uberipalpi s (K. Viets, 1913) Distr: Cameroon 222 A. (Atractides) valididens (Lundblad, 1951) Distr: Kenya, Tanzania A. (Megabates) rectipes (K. Viets, 1924) Distr: Cameroon A. (Megabates) vietsi (Cook, 1966) Distr: Liberia A. (Octomegapus) minutissimus (Lundblad, 1927) Distr: Kenya A. (Polymegapus) multiporus Cook, 1966 Distr: Liberia A. (?) spec. (~ Type A) Cook, 1966 Distr: Liberia A. (?) spec. (~ Type B) Cook, 1966 Dis tr: Liberia A. (?) spec. (~ Type C) Cook, 1966 Distr: Liberia Genus HYGROBATOPSIS K. Viets, 1924 H. Zevipalpis K. Viets, 1924 Distr: Cameroon, Kenya, Zaire, S. Africa Genus TETRABATES Th_or, 1922 T. (Tetrabates) uvirensis (Bader, 1968) Distr: Zaire T. (Tetrabates) williamsoni (K. Viets, 1913) Distr: Cameroon, Liberia, Zaire, S. Africa T. (Liberiobates) bomiensis (Cook, 1966) Distr: Liberia Genus AUSTRALIOBATES Lundblad, 1941 A. (Australiobates) pilosus (K. Viets, 1956) Distr: S. Africa Genus AMBIGUOBATES K. Viets, 1956 A. permixtus permixtus (K. Viets, 1956) Distr: S. Africa A. permixtus agnewi (K. 0 • Viets , 19 6 3) Distr: S. Africa 223 Genus AMBIGU0BATELLA K. Viets, 1956 A. peZtophoT'Us (K. Viets, 1956) Distr: S. Africa Genus PLESI0HYGR0BATES K. Viets, 1956 P. pectinipalpis K. Viets, 1956 Distr: S. Africa Genus AFRICACARUS K.0. Viets, 1962 A. str enzkei K.0. Viets, 1962 Distr: S. Africa Family UNIONIC0L IDAE Thor, 1900 Subfamily ENCENTRID0PH0RINAE K. Viets, 1935 Genus ENCENTRID0PH0RUS Piersig, 1897 E. (Encentridophorus) acutipes K. Viets, 1921 Distr: Kenya, Zaire, Ivory Coast, Lake Chad, Sudan E. (Encentr idophorus ) alatus Cook, 1966 Dis tr: Liberia E. (Encent r i dophoT'Us) borgerti Daday, 1907 Distr: Uganda E. (Encentridophorus ) brevi spi nus Lundblad, 1946 Distr: Madagascar E. (Encetridophorus ) koenikei Daday, 1908 Distr: Tanzania E. (Encentri dophorus) multi porus K. Viets, 1916 Distr: Cameroon, Liberia E. (Encentri dophorus) projectus Cook, 1966 Dis tr: Liberia E. (Encentridophorus) spini f er (Koenike, 1893) Distr: Tanzania, Zambia, Mozambique, Sudan, Cameroon, Chad Region, Zanzibar, Madagascar, S. Africa E. (EncentridophoT'Us ) tumid.us Walter, 1937 Distr: Liberia, Angola E. (Encentr i dophor ellus) fal catus Bader, 1968 Distr: Zaire E. (Encentridophor ellus ) f alci pes Lundblad, 1951 Distr: Kenya 224 Subfamily UNIONIC0LINAE 0udemans, 1909 Genus UNIONIC0LA Haldeman, 1842 U. (Unionicola) crassipes (Muller, 1776) Distr: S. Africa, Uganda, Europe, Asia, N. America U. (Unionicola) eyclophora K. Viets, 1913 Distr: Cameroon, Liberia U. (Unionicola) dentifera Cook, 1966 Dis tr: Liberia U. (Unionicola) inflexa K. Viets, 1921 Distr: Tanzania, Ivory Coast, Zaire, Mauritania U. (Unionicola) pollicigera K. Viets, 1921 Distr: Mozambique, Angola, Ivory Coast, Uganda, Kenya U. (Unionicola) tridentifera K. Viets, 1921 Distr: Uganda U. (Pentatax) borgerti borgerti (Daday, 1907) Distr: Zaire, Uganda U. (Pentatax) borgerti lineata K. Viets, 1925 Distr: Cameroon U. (Pentatax) chappuisi W~lt~r, 1935 Distr: Ivory Coast, Angola, Sudan U. (Pentatax) dadayi Cook, 1966 Distr: Liberia U. (Pentatax) digitata (Ko enike, 1898) Distr: Nossi Be, Tanzania U. (Pentatax) falcifera (Daday, 1907) Distr: Zaire, Uganda, Zambia U. (Pentatax) figuralis (Koch, 1836) Distr: Uganda, Zambia, Europe, Asia, America U. (Pentatax) firribriata K. Viets, 1913 Distr: Cameroon, Ivory Coast U. (Pentatax) harpax (Koenike, 1898) Distr: Nossi Be, Tanzania U. (Pentatax) koenikei K. Viets, 1913 Distr: Cameroon, Ivory Coast, Liberia, Angola, Asia 225 U. {Pentatax) ZatiZcuninata K. Viets, 1911 Distr: Cameroon, Rio Muni, Liberia U. {Pentatax) Zyncea (Koenike, 1895) Dis tr: Zaire U. {Pentatax) megaZopsis K. Viets, 1925 Distr: Cameroon U. {Pentatax) minuta K. Viets, 1916 Distr: Cameroon, Ivory Coast U. {Pentatax) postmarginata K. Viets, 1925 Distr: Cameroon U. {Pentatax) uncata K. Viets, 1916 Distr: Cameroon, Zaire, Ethiopia U. {Pentatax) vietsi Walter, 1935 Distr: Cameroon U. {Bassatax) separata Cook, 1966 Distr: Liberia Genus HETERATAX Lundblad, 1941 H. faZcipes Lundblad, 1941 Distr: S. Africa, Zaire Supfamily PIONATACINAE K. Viets, 1916 Genus NEUMANIA Lebert, 1879 N. {Neumania) aequaZis K.O. Viets, 1962 Distr: S. Africa N. (Neumania) aZtipaZpis Walter & Bader, Distr: Kenya 1952 N. (Neumania) circumcincta K. Viets, 1925 Distr: Cameroon N. (Neumania) curtipaZpis K.O. Viets, 1962 Distr: S. Africa N. (Newnania) discrepans Walter & Bader, Distr: Kenya 1952 N. (Neumania) fissa K. Viets, 1913 Distr: Cameroon, Ivory Coast N. (Neumania) granuZosa Walter, 1935 Distr: Ivory Coast N. {Neumania) inaequaZis K.O. Viets, 1962 Distr: S. Africa 226 N. (Newnania) incerta K. Viets, 1913 Distr: Cameroon N. (Newnania) Ziberi ensis Cook, 1966 Dis tr: Liberia N. (Newnania) marginata K. Viets, 1916 Distr: Cameroon, Ivory Coast, Kenya, Zaire, S. Africa N. (Newnania) megalopsis K. Viets, 1913 Distr: Cameroon N. (Newnania) meridiana K. Viets, 1959 Distr: S. Africa N. (Newnania) naivashensis Walter & Bader, Distr: Kenya 1952 N. (Newnania) nudipes K. Viets, 1913 Distr: Cameroon N. (Newnania) parva Walter, 1935 Distr: Ivory Coast N. (Neumania) paucipora paucipora (Koenike, 1895) Distr: Tanzania, Uganda, Cameroon, Fernando Poo, Liberia, Zaire N. (Newnania) pentagona K. Viets, 1916 Distr: Cameroon N. (Newnania) procera K.O. Viets, 1962 Distr: S. Africa N. (Newnania) proxima K. Viets, 1914 Distr: S. Africa N. (Newnania) reticulata K. Viets, 1913 Distr: Liberia, Cameroon N. (Newnania) subrubra K. Viets, 1916 Distr: Cameroon N. (Newnania) ulcerosa K.O. Viets, 1962 Distr: S. Africa N. (Newnania) vernalis (Muller, 1776) Distr: Tanzania, Europe, Asia N. (Newnania) verrucipora K. Viets, 1959 Distr: S. Africa N. (Newnania) spec. K.O. Viets, 1962 Distr: S. Africa 227 N. (Socanus K. Viets, 1942 Distr: Tanzania A. (?) convexus Thor, 1902 Dis tr: s. Africa A. (?) cupitor Koenike, 1898 Dis tr: Madagascar A. (?) dwnazeri Mota~, 1932 Distr: s. Africa, Madagascar A. (?) fars ilis Koenike, 1898 Dis tr: Nossi Be A. (?) gibbus Koenike, 1893 Dis tr: Tanzania, Zanzibar, Sudan A. (?) indiseretus Walter & Bader Dis tr: Kenya 1952 A. (?) plenipalpis Koenike, 1893 Distr: Mozambique A. (?) praecox Bader, 1964 Dis tr: Tanzania A. (?) procerus Walter, 1931 Distr: Ethiopia A. (?) retroduobus Miinchberg, 1959 Distr: Zaire 244 A. (?) viduus K. Viets, 1914 Dis tr: Cameroon, Sudan A. (?) vigorans Koenike, 1898 Distr: Nossi Be, Tanzania A. spec. K. Viets, 1921 Distr: Tanzania A. spec. Hutchinson, 1932 Distr: S. Africa A. spec. Walter, 1935 Distr: Ivory Coast A. spec. K. Viets, 1959 Distr: S. Africa A. spec. K.O. Viets, 1964 Distr: Madagascar A. spec. K.O. Viets, 1965 Distr: S. Africa A. spec. Female A Bader & Van Distr: S. Africa Rensburg, 1968 A. spec. Female B Bader & Van Distr: S. Africa Rensburg, 1968 A. spec. Nymphs Bader & Van Distr: S. Africa Rens burg, 1968 Nympha incomperta K. Viets, 1914 Distr: Cameroon Genus THORACOPHORACARUS K. Viets, 1914 T. (Thoracophoraccwus) arrhenu:roides K. Viets, 1914 Dis tr: Cameroon T. (Thoracophoraccwus) gibberosus K.O. Viets, 1962 Distr: S. Africa T. (Thoracophoracarus) kuhnei K. Viets, 1916 Distr: Cameroon T. (Thoracophorurus) mammosus K. Viets, 1925 Dis tr: Cameroon T. (Thoracophoraccwus) petioluriger K. Viets, 1925 Distr: Cameroon T. (Thoracophoracar>us) rivularis Lundblad, 1951 Distr: Kenya 245 T. (Thoracophoracarus) whartoni Cook, 1966 Dis tr: Liberia Genus HAMAPPENDIX Walter & Bader, 1952 H. chappuisi Walter & Bader, Distr: Kenya 1952 Genus ALLARRENURUS K.O. Viets, 1961 A. pudens (Koenike, 1898) Distr: Madagascar, Nossi Be Genus WURIA K. Viets, 1916 W. fafois eta K. Viets, 1916 Distr: Cameroon MITES OF UNCERTAIN GENERA Genus EUPATRELLA Walter, 1935 E. r eticulata Walter, 1935 Distr: Ivory Coast, Zaire p A R T V 246 16. 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Arachnida & Myriapoda (140-186, 912-924). 263 17. ACKNOWLEDGEMENTS I am greatly indebted to Professor J.A. van Eeden, Head of the Depart- ment of Zoology and Professor P.A.J. Ryke, Director of the Institute of Zoological Research for the interest shown and the encouragement given during my years of study at the Potchefstroom University for C.H.E. I would like to express my appreciation to Professor P.A.J. Ryke, my Promoter, and especially to Dr G.C. Loots the Assistant Promoter for the guidance during the course of this investigation. I am grateful to Dr Carl Bader of the Museum of Natural History, Basel, Switzerland for acquainting me with water mites, for his able guidance during my stay in Switzerland, and for the use of his library and his various catalogues. Sincere thanks are due to Professor C. Mota~ of the University of Bucarest, Rumania, for the valuable information and his review of the published part of this investigation, and to Dr Jurgen Schwoerbel of the University of Freiburg, Germany, for putting at my disposal his preparations and giving me advice at the beginning of this investigation. My thanks are extended to Professor M. Webb of the University of Durban- Westville for his interest in this work, his encouragement and criticism of the manuscript; Dr V.L. Hamilton-Attwell for his assistance with the S.E.M. work; Dr P.D. Theron for the informative discussions and assistance during my stay at the University; my wife Annette for her help and patience during this investigation. Sincere thanks are due to Miss S. Singh for the typing and the University of Durban-Westville for the use of the printing facilities. Finally I would like to acknowledge the financial assistance of the C.S.I.R. and the Swiss Confederate Scholarship Commission. 264 18. 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