Caecopilumnus Borradaile, 1902

Ng, Peter K. L. & Rahayu, Dwi Listyo, 2014, Revision of the family Acidopsidae Števčić, 2005, and the systematic position of Typhlocarcinodes Alcock, 1900, Caecopilumnus Borradaile, 1902, and Raoulia Ng, 1987, with descriptions of two new genera and five new species (Crustacea: Brachyura: Goneplacoidea), Zootaxa 3773 (1), pp. 1-63 : 35-36

Caecopilumnus Borradaile, 1902

Caecopilumnus Borradaile, 1902: 237 .— Tesch 1918: 226 (part).— Ng 1987: 91 (part).— Ng et al. 2008: 143 (part).

Diagnosis. Carapace subovate to subquadrate; dorsal surface convex, covered with numerous small granules, setose; regions separated by shallow or deep grooves; front entire, margin rounded, bent downwards, lined with numerous long setae obscuring margin; anterolateral margin arcuate, granular, densely hirsute, setae obscuring margin, never distinctly dentate, sometimes with low granuliform lobes covered with several small, large tubercles, granules; anterolateral margins separated from gently converging posterolateral margins. Epistome narrow, prominently sunken. Basal antennal 3 rectangular, longer than wide; article 4 dorsoventrally flattened, twice as long as broad, margins with numerous long plumose setae. Basal antennular article subovate; antennules folding obliquely. Eyes immobile, pear-shaped, tapering to very small cornea, cornea pigmented partially or absent. Third maxillipeds relatively short, leaving narrow gap when closed; merus quadrate to rounded, anterolateral angle rounded; exopod relatively narrow, with long flagellum. Outer surface of palm covered by numerous large tubercles, granules. Propodus, dactylus of last ambulatory leg short. Male thoracic sternum relatively narrow, st1, 2 completely fused to form triangular plate, st3, 4 fused with only lateral sutures discernible; sterno-abdominal cavity reaching to imaginary line joining posterior third of coxae of chelipeds; penis sits exposed between short groove between st7, 8; large part of st8 exposed when abdomen closed, subquadrate in shape; press-button mechanism for holding male abdomen as small rounded tubercle on posterior third of st5. Male abdomen with a1 reaching cx5, lateral parts subtruncate, somite appearing broadly subrectangular; lateral margin of a3 strongly produced, forming acutely triangular structure; a3–5 fused, with sutures visible or shallow. Gl relatively stout, distal surfaces with numerous spinules; G2 as long as G1, distal segment half length of proximal segment.

Remarks. The taxonomy for this genus has been discussed at length in the remarks for the subfamily Raouliinae , and the genera Raoulia and Thecaplax gen. nov. Because the type species, C. hirsutus Borradaile, 1902 , is poorly known and represented only by a poorly preserved male and a female, a complete description of C. crassipes is given instead.