Water mites from caves of the Ha Giang province, northern Vietnam (Acari: Hydrachnidia) Author Pešić, Vladimir Author Gerecke, Reinhard text Zootaxa 2014 3774 4 367 380 journal article 46271 10.11646/zootaxa.3774.4.5 3dbd5beb-a25d-4dcb-b0b7-87108232d4ae 1175-5326 229333 53BF8506-352F-49A4-83E9-D91D8FF635A8 Genus Stygotorrenticola gen. nov. Diagnosis. Ocular pigment absent; shoulder platelets fused to the dorsal plate, frontal platelets fused to each other to form a narrow, transverse platelet; Cxgl-4 subapical; suture lines Cx-I/ -II complete, not meeting in the medial line, but separately ending at anterior genital field margin; suture line Cx-II/III developed only in lateral quarter; suture lines of Cx-IV not visible; excretory pore on the limit of primary sclerotization near posterior idiosoma margin; P-2 with a stout, pointed peg-like seta on a pointed, anteriorly directed distoventral projection; P-3 with similar seta on a pointed projection in the centre of segment; P-4 slender, ventral margin with 5 setae; chelicera basal segment inflated in the centre, claw short and curved; gnathosomal rostrum shortened, ventrally not evidently set off from base. Type species. Stygotorrenticola coniseta sp. nov . Etymology. “ stygo ” (meaning adapted to living underground and referring to the River Styx in Greek and Roman mythology) is prefixed to the existing genus name Torrenticola . Remarks. Stygotorrenticola differs from all other torrenticolid genera in (1) absence, in both sexes, of a medial suture Cx-II+III, and (2) presence of strong, peg-like setae on ventral protuberances of P-2/-3. The genus is similar to Monatractides in the stout gnathosoma with short rostrum, but to Torrenticola in the enlarged, U-shaped gnathosomal bay and the presence of distoventral projections on P-2/-3. Possibly, the development of peg-like palp setae (probably of sensory function) can be considered a compensation for light sensitivity due to reduction of lateral eyes.