Revision of the family Chasmocarcinidae Serène, 1964 (Crustacea, Brachyura, Goneplacoidea) Author Ng, Peter K. L. Author Castro, Peter text Zootaxa 2016 4209 1 1 182 journal article 37321 10.11646/zootaxa.4209.1.1 2de5b7bf-3975-458a-b200-07ec69f4e013 1175-5326 272646 849BAB5C-464A-4B4A-A586-5742411EDC01 Tenagopelta brachyphallus n. sp. ( Figs. 17 C, D; 26G; 33H; 47C, D; 54G; 61F; 79F‒J; 88D; 91H) Type material . Holotype male (6.1 × 6.9 mm ) ( NMV J61680 ) [photographed], Western Australia , “ Chasmocarcinops , det. A. McCallum 2009 ”), L23 west transect , Western Australia , 17°31’03”S –17°31’43”S to 118°51’10”E–118°50’44”E, 405 m , M.F. Gomon coll., 16.06.2007 . Paratypes: 1 male (6.9 × 7.6 mm ) (NMV J54594 ); 3 females (6.9 × 7.6 mm , 5.2 × 5.6 mm , 7.4 × 8.1 mm ) ( NMV J54594 ) [“ Camatopsis rubida , det. C.G.B. Poore 2006”], Western Australia , off Ningaloo North , 21°58’42”S , 113°49’12”E to 21o59’03”S , 113o49’12”E , 170–177 m , 10.12.2005 ; 1 female (6.9 × 7.6 mm ) [photographed], 2 females (5.2 × 5.6 mm , 7.4 × 8.1 mm ) (NMV J61680 ) [“ Chasmocarcinops , det. A. McCallum 2009 ”], L23 west transect, 17o31’03”S, 118o51’10”E to 17o31’43”S, 118o50’44”E, 405 m , M.F. Gomon coll., 16.06.2007 . Diagnosis . Carapace ( Fig. 17 C, D) subtrapezoidal, globose, 1.1 wider than long; front bilobed, with shallow median cleft; anterolateral margins arcuate, minutely granular, low tubercle on each anterolateral margin in holotype , small individuals (absent in large specimens). Eye peduncle ( Fig. 26 G) tightly filling orbit, short, mobile; cornea reduced, pigmented. Posterior margin of epistome ( Fig. 26 G) with broad semicircular median lobe with deep median fissure, semicircular lateral margins. Third maxilliped ( Fig. 33 H) merus quadrate, ischium rectangular, about same length as merus. Chelipeds ( Figs. 17 C, D; 47C, D) subequal in length, slightly dissimilar in females, heteromorphic in males; fingers of minor chela ( Fig. 47 D) subcircular in cross-section, not distinctly laterally flattened, gently tapering to tip, scissor-like, cutting margins with distinct sharp teeth; major chela of males ( Fig. 47 C) with most proximal dactylar tooth enlarged. Ventral surface of cheliped merus with 3 large teeth (sometimes additional small teeth or large tubercles) on outer margin in both sexes. Inner margin of cheliped carpus with long distal tooth ( Fig. 17 C, D). Proportionally long ambulatory legs ( Fig. 17 C, D); P5 merus 0.8 cl. Meri of P2, P3 with minute teeth. Fused thoracic sternites 1, 2 ( Fig. 54 G) semicircular, broad, short. Male pleon ( Figs. 54 G; 61F) with proportionally short telson. G1 ( Fig. 79 F‒I) short, stout, distal half short, stout straight, with short spinules; tip sharp. G2 ( Fig. 79 J) longer than G1, curved, slender, distal segment long, curved. Female telson ( Fig. 88 D) proportionally short. Sterno-pleonal cavity of female ( Fig. 91 H) deep, vulvae widely separated on outer margins of cavity close to suture 5/6. Etymology . The name alludes to the relatively short G1 of the species. The name is used as a noun in apposition. Remarks . Specimens of T. brachyphallus n. sp. were collected from waters that are shallower (about 400 m ) than its two congeners. There is slight variation in the five specimens. In the holotype, paratype male and one paratype female (6.9 × 7.6, NMV J61680 ), there is a short but distinct tooth on each anterolateral margin. This tooth is strongly reduced in a small paratype female (5.2 × 5.6 mm , NMV J61680 ) and completely absent in the largest paratype female (7.4 × 8.1 mm , NMV J61680 ). Distribution . Known only from Western Australia . Depth: 170– 405 m .