Revision of the status of some genus-level water mite taxa in the families Pionidae Thor, 1900, Aturidae Thor, 1900, and Nudomideopsidae Smith, 1990 (Acari: Hydrachnidiae) Author Smith, Ian M. Author Cook, David R. Author Gerecke, Reinhard text Zootaxa 2015 3919 1 111 156 journal article 10.11646/zootaxa.3919.1.6 4c40552e-e778-4d8e-a6b7-9662436cadc2 1175-5326 244587 F711CA99-1B2C-4E18-9F4B-7521D38D2303 Genus Ocybrachypoda Cook, 1974 stat. nov. Brachypoda ( Ocybrachypoda ) : Cook, 1974a , pp. 340–341, figs. 1432, 1433, 1435, 1438, 1444. Brachypoda ( Ocybrachypoda ) : Cook, 1975 , pp. 281–289, figs. 8–25 Brachypoda (in part): Smith, 1984, pp. 316–317, figs. 35–42. Brachypoda ( Ocybrachypoda ) : Cook, 1981 , pp. 98–104, figs. 30, 31, 33–45. Brachypoda (in part): Smith & Cook, 1991 , pp. 553, 577, fig. 16.148. Brachypoda (in part): Smith et al ., 2001 , pp. 581, 614, figs. 163, 164, 359, 363. Brachypoda (in part): Smith et al ., 2010 , pp. 523, 555, figs. 15.163, 15.164, 15.360, 15.364. Diagnosis. Larva (modified from Smith 1984 and based on larvae of O. setosicauda (Habeeb) , only species in genus with known larvae): Character states of Brachypoda -like mites. Third coxal plate with medial coxal apodeme absent and transverse muscle attachment scar present. Posterior edge of third coxal plate bearing prominent lobed projection. Excretory pore plate much larger than excretory pore and nearly quadrangular in shape, bearing setae ps1, ps2 , and h2 posterolaterally with ps2 displaced medially. Numbers of setae on leg segments as follows: ITi 8 (seta Ti10 absent); ITa 11 (setae Ta8 and Ta14 absent); IITa 11 (setae Ta8 and Ta14 absent). Adults (modified from Cook 1974a , 1975 ): Character states of Brachypoda -like mites. Dorsal shield of males without a slight bulge posterior to midlength and lacking enlarged glandularia with extremely long associated setae. Ventral shield of males lacking a pronounced ridge extending anterolaterally from genital field. Fourth coxal plate with opening for insertion of fourth leg lacking condyles; lacking a ridge extending posteriorly from region of insertion of fourth legs. Genital field bearing three pairs of acetabula; genital field of males located well anterior to posterior edge of ventral shield and relatively wide, with acetabula extending laterally into region beyond level of insertion of fourth leg and with a patch of long setae immediately lateral to acetabula. Excretory pore borne on dorsal shield near posterior edge or on separate small platelet posterior to dorsal shield. Fourth leg of males with genu bearing a patch of spatulate setae distoventrally but lacking a distal projection that extends well beyond level of insertion of tibia, tibia slightly bowed and bearing a row of swimming setae posteriorly, and tarsus slightly expanded distally and bearing modified claw socket with highly modified claws. Pedipalp femur bearing a distoventral projection and tibia bearing a thick seta on a ventral projection. Type species. Brachypoda acuticauda Habeeb. Species included. Ocybrachypoda acuticauda (Habeeb) (eastern North America ), O. affinis (Cook) (eastern North America ), O. celeripes (Viets) (Europe) , O. coerulea (Cook) (western North America ), O. fimbricaudata (Cook) (eastern North America ), O. laversi (Cook) (western North America ), O. milicaae Pešić & Semenchencko ( South Korea ), O. oakcreekensis (Habeeb) (western North America ), O. ojaiensis (Cook) (western North America ), O. setosicauda (Habeeb) (eastern North America ), O. sokolowi (Pešić & Semenchencko) ( Russia ) , O. splendens (Cook) (southwestern North America ). Distribution. Holarctic (North America , Eurasia). Discussion. Cook (1974a , 1975 , 1981 ) considered Ocybrachypoda to be a subgenus of Brachypoda . Smith (1984), Smith & Cook (1991) , and Smith et al . (2001 , 2010) followed this treatment. Here we propose elevation of this taxon to full generic status based on the unique combination of character states listed above.