Geogamasus Lee

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 : 15

Geogamasus Lee (33 described species)

Movable and fixed cheliceral digits with 2–4 and 4–6 teeth, respectively. Epistome with a club-shaped anteromedian extension, usually flanked by one or more pairs of large anterolateral extensions, as long as or shorter than anteromedian extension. Seta h 3 about in longitudinal line with h 1 and in transverse line, slightly anterior or anterior and mediad to h 2. Idiosoma elongate or suboval, 240–510 µm long and 120–370 µm wide at widest level. Podonotal and opisthonotal shields separated, or fused to form a holonotal shield. Dorsal idiosomal setae aciculate. Podonotal region of dorsum with 20–23 pairs of setae, of which 20–23 pairs on podonotal shield and without setae on soft integument along lateral margins of podonotal shield (two pairs in G. apophyseus ). Opisthonotal region with 15–20 pairs of setae, of which 15–20 pairs on opisthonotal shield and without setae on soft integument along lateral margins of opisthonotal shield (one pair in G. monocuspidis ). Seta j 1 not on prominent protuberance, shorter than r 3 and Z 5. Opisthonotal and ventrianal shields not fused. With one pair of presternal platelets (without in G. monocuspidis ). Sternal shield not fused to endopodal shield near coxa IV; setae st 1– st 4 in longitudinal line. Opisthogaster with 0–4 platelets between genital and ventrianal shields; with 6–7 pairs of setae on ventrianal shield and 0–1 pair on soft integument around ventrianal shield; post-anal seta as long as or shorter than para-anal seta (longer in G. skoshi ). Peritreme with straight or smoothly curved margins, extending anteriorly to level between posterior margin of coxa III and middle of coxa II. Peritrematal shield fused posteriorly to exopodal shield near coxa IV, with connection behind stigma narrower than peritreme. Exopodal shields near coxae II–III–III fused or divided at median level of coxa III. Without distinct metapodal platelets. All legs with pretarsi. Genua I, III and IV and tibia IV with 13, 9, 9–10 and 10 setae, respectively.