Hydrogamasus Berlese

Castilho, Raphael C., Silva, Edmilson S., De, Gilberto J. & Halliday, Bruce, 2016, Catalogue of the family Ologamasidae Ryke (Acari: Mesostigmata), Zootaxa 4197 (1), pp. 1-147 : 16

Hydrogamasus Berlese (4 described species)

Movable and fixed cheliceral digits with 3–6 and six teeth, respectively. Epistome with an anteromedian extension wider at base, flanked by one pair of large anterolateral spines, shorter than anteromedian extension. Seta h 3 about in longitudinal line with h 1 and posterior and mediad to h 2. Idiosoma elongate, 600–910 µm long and 310–470 µm wide at widest level. Podonotal and opisthonotal shields fused, forming holonotal shield. Dorsal idiosomal setae aciculate. Podonotal region of dorsum with 20 pairs of setae, of which 20 pairs on podonotal shield and without setae on soft integument along lateral margins of podonotal shield. Opisthonotal region with 18 pairs of setae, of which 18 pairs on opisthonotal shield and without setae on soft integument along lateral margins of opisthonotal shield. Seta j 1 not on prominent protuberance, shorter than r 3 and Z 5. Holonotal and ventrianal shields fused. Two pairs of presternal platelets present. Sternal shield not fused to endopodal shield near coxa IV; setae st 1– st 4 in longitudinal line. Opisthogaster with 0–1 platelet between genital and ventrianal shields; with seven pairs of setae on ventrianal shield and without setae on soft integument around ventrianal shield; post-anal seta longer than para-anal seta. Peritreme with straight or smoothly curved margins, extending anteriorly to level of coxa I. Peritrematal shield fused posteriorly to exopodal shield near coxa IV, with connection behind stigma wider than peritreme. Exopodal shields near coxae II–III–III fused (divided at median level of coxa III in H. giardi ). Without distinct metapodal platelets. All legs with pretarsi. Genua I, III and IV and tibia IV with 13, 9, 9 and 9 setae, respectively.