Hydrogamasellus Hirschmann

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

Hydrogamasellus Hirschmann (21 described species)

Movable and fixed cheliceral digits with 3–4 and 4–12 teeth, respectively. Epistome with an anteromedian extension wider at base, acute or bifurcate distally, with one to several spines along its median region. Seta h 3 about in longitudinal line with h 1 and slightly anterior and mediad to h 2. Idiosoma elongate or suboval, 430–1120 µm long and 290–720 µm wide at widest level. Podonotal and opisthonotal shields fused, forming holonotal shield (separated in H. crozetensis and H. racovitzai ). Dorsal idiosomal setae aciculate (spatulate and with distal half pilose in H. alagoensis ). Podonotal region of dorsum with 18–22 pairs of setae, of which 18–22 pairs on podonotal shield and without setae on soft integument along lateral margins of podonotal shield. Opisthonotal region with 12– 20 pairs of setae, of which 12–20 pairs on opisthonotal shield and without setae on soft integument along lateral margins of opisthonotal shield (two pairs in H. racovitzai ). Seta j 1 not on prominent protuberance, shorter than or as long as r 3 and Z 5. Holonotal and ventrianal shields not fused. With one pair of presternal platelets. Sternal shield not fused to endopodal shield near coxa IV; setae st 1– st 4 in longitudinal line or st 4 slightly lateral to st 1– st 3. Opisthogaster with 0–4 platelets between genital and ventrianal shields; with 5–7 pairs of setae on ventrianal shield and 0–2 pairs on soft integument around ventrianal shield; post-anal seta longer than, as long as or shorter than para-anal seta. Peritreme with straight or smoothly curved margins, extending anteriorly to level between middle region of coxa III and coxa I. Peritrematal shield fused posteriorly to exopodal shield near coxa IV, with the connection behind stigma wider or narrower than peritreme. Exopodal shields near coxae II–III–III divided at median level of coxa III (fused in H. multospinosus and H. nasutus ). Without distinct metapodal platelets (with a pair of rounded platelets in H. racovitzai ). All legs with pretarsi, pretarsus I pedunculate and smaller than other pretarsi. Genua I, III and IV and tibia IV with 13, 9, 9–10 and 10 setae, respectively. Insemination pore located on coxa III.