North American species of Diamphidaxona (Acari: Hydrachnida: Hygrobatidae) Author Smith, Ian M. Author Cook, David R. text Zootaxa 2006 1279 1 44 journal article 10.5281/zenodo.173379 2ba624cc-0ed0-4df0-8196-7783512b7ecc 1175­5326 173379 Key for adults of north american species of Diamphidaxona 1a. Gnathosoma with rostrum short and not extending beyond insertion of pedipalps ( Figs. 7 , arrow, 22, 53); pedipalps with segments relatively long and slender ( Figs. 5 , 20 , 51 ) ............................................................ Diamphidaxona (s. s.) 2 1b. Gnathosoma with rostrum long and extending well beyond insertion of pedipalps ( Figs. 68 , arrow, 72, 78, 84, 94) and pedipalps with segments relatively short and stocky ( Figs. 66 , 71 , 77 , 83 , 91 ) ............................................................ ............................................................. Diamphidaxona (Diamphidaxonella) 10 2a (1a). Suture lines between third and fourth coxal plates with lateral loops drop­shaped and closed anteriorly ( Figs. 3, 6 )......................................... D. cramerae sp. nov. 2b. Suture lines between third and fourth coxal plates with lateral loops U­shaped and open anteriorly ( Figs. 10, 15 ) ....................................................................... 3 3a (2a). Dorsal portion of camerostome strongly acutely angled and projecting beyond anterior end of idiosoma ( Figs. 10, 15 ; arrows) .................... D. imamurai Cook 3b. Dorsal portion of camerostome weakly acutely angled or rounded and not extending beyond anterior end of idiosoma ( Figs. 18, 21 , 56, 59 )...................... 4 4a (3b). Ventral shield with projections covering insertions of fourth pair of legs relatively short and extending laterally to edges of shield ( Figs. 18, 21 ) ................... ........................................................................................... D. chihuahua sp. nov. , 4b. Ventral shield with projections covering insertions of fourth pair of legs relatively long and extending anteriorly parallel to edges of shield ( Figs. 25, 28 , 56, 59 )........................................................................................................................ 5 5a (4b). Pedipalps with ventral spine­like setae on tarsus lacking denticles ( Fig. 27 ) ....... ............................................................................................ D. dolichosoma Cook 5b. Pedipalps with ventral spine­like setae on tarsus bearing ventral denticles ( Figs. 32 , 39 , 51 , 57 ) .................................................................................................... 6 6a (5b). Pedipalps with tarsus relatively short and stocky, with ventral spine­like seta extending only slightly beyond end of segment and bearing two relatively large and strongly recurved ventral denticles ( Fig. 32 , arrow)....................................... ......................................................................................... D. sabinalensis sp. nov. 6b. Pedipalps with tarsus relatively much longer and more slender, with ventral spine­like seta extending well beyond end of segment and bearing relatively small, straight or slightly curved ventral denticles ( Figs. 39 , 51 , 57 ) ................. 7 7a (6b). Suture lines between third and fourth coxal plates with medial loops bearing glands of fourth coxal plates relatively shallow ( Figs. 37, 40 , 43 ) ................... 8 7b. Suture lines between third and fourth coxal plates with medial loops bearing glands of fourth coxal plates relatively deeply arched ( Figs. 49, 52 , 56, 59 ) ..... 9 8a (7a). Idiosoma and appendages relatively large in size (ventral shield of female more than 490 μm in length); posterior dorsal plate slightly narrowed near midlength ( Fig. 35 ); leg segments relatively long and slender ( Figs. 36, 38 ) ........................ ........................................................................................... D. chiricahua sp. nov. 8b. Idiosoma and appendages relatively small in size (ventral shield of female less than 450 μm in length); posterior dorsal plate slightly widened near midlength ( Fig. 42 ); leg segments relatively short and stocky ( Figs. 45, 46 ) ........................ ..................................................................................... D. cavecreekensis sp. nov. 9a (7b). Dorsal shield relatively long and slender ( Fig. 47 ); male with genital acetabula relatively small and first pair widely separated from second and third pairs ( Fig. 49 ) ................................................................................ D. parvacetabula sp. nov. 9b. Dorsal shield relatively short and wide ( Fig. 54 ); male with genital acetabula relatively large and first pair closer to second and third pairs ( Fig. 56 ) ................... ..................................................................................................... D. pallida Cook 10a (1b). Pedipalps with segments very short and stocky and tibia bearing 2 ventral setae ( Fig. 66 ) ......................................................................... D. neomexicana sp. nov. 10b. Pedipalps with segments relatively long and slender and tibia bearing 1 ventral seta ( Figs. 71 , 77 , 83 , 91 ) ................................................................................. 11 11a (10b). Fourth pair of legs with tarsi short and stocky ( Fig. 74 ) ..................................... ............................................................................................ D. brevitarsa sp. nov. 11b. Fourth pair of legs with tarsi relatively long ( Figs. 80 , 86 , 88 )......................... 12 12a (11b). Dorsal shield relatively wide and with maximum width in anterior region of anterior plate ( Fig. 75 ) ........................................................ D. platysoma sp. nov. 12b. Dorsal shield relatively narrow and with same width throughout or maximum width in posterior region of posterior plate ( Figs. 81 , 87 ) ................................ 13 13a (12b). Dorsal shield with anterior plate relatively long and strongly pointed anteriorly ( Fig. 81 ) ............................................................................ D. californica sp. nov. 13b. Dorsal shield with anterior plate relatively short and weakly pointed anteriorly ( Fig. 87 ) ............................................................................... D. arizonica sp. nov.