Carcinological Fauna of India. 183 



next joint at its summit. Chelipedes in the male rather small, with the 

 palm turgid, and the fingers having between them, when closed, an 

 interspace at the base. Ambulatory legs slender and [somewhat 

 elongated, with the penultimate joints of the first and second pairs 

 dilated, compressed, and ciliated on the posterior margin ; the dactyli 

 in all slightly arcuated and retractile against the penultimate joints." 



Oncinopus aranea, de Haan. 



Inachus (Oncinopus) aranea, de H., Faun. Japon. Crust., p. 100, pi. xxix. fig. 2. 



Oncinopus aranea, Adaras and White, Zool. ' Samai'ang,' Crust., p. 3. 



Oncinopus neptunus, Adams and White, Zool. ' Samarang,' Crust., p. 1, pi. ii. 

 fig. 1. 



Oncinopus subpellucidus, Stimpson, Proc. Acad. Nat. Sci. Philad., 1857, p. 221. 



Oncinopus angulatus, Haswell, Proc. Linn. Soc, N\ S. Wales, IY. 1879, p. 433. 



Oncinopus subpellucidus, Haswell, Cat. Austr. Crust., p. 5. 



Oncinopus aranea, Miers, Zool. 'Alert,' pp. 182 and 190; and 'Challenger' 

 Brachyura, p. 20. 



Oncinopus neptunus. Walker, Journ. Linn. Soc, Zool., Yol. XX. 1890, p. 109. 



Oncinopus aranea, Henderson, Trans. Linn. Soc, Zool., (2) Y. 1893, p. 341. 



Oncinopus aranea, Ortmann, Zool. Jahrb., Syst. etc, YII. 1893, p. 37. 



Oncinopus neptunus, Alcock and Anderson, J. A. S. B., Pt. ii. 1894, p. 199. 



Carapace elongate-triangular, thin and semi-membranous, and, 

 as well as all the appendages, tomentose. Rostrum short, bilobed. 



Eyes small, retractile beneath the edge of the carapace : no orbits 

 or protective spines. 



Antennee extremely short, reaching only just beyond the tip of the 

 rostrum : the basal joint short and free. 



Chelipeds in the female and young male slenderer than the next 

 legs and not quite equal in length to the carapace ; in the adult male 

 about as stout as the next legs, with an inflated almost globose palm, 

 and a little longer than the carapace. 



The 2nd and 3rd pair of legs differ very markedly from the 4th 

 and 5th pair. The 2nd and 3rd pair are long and stout, with a com- 

 paratively short carpopodite, with a long broad propodite, and with a 

 comparatively slightly curved dactylus — all these joints being remark- 

 ably setaceous. The 4th and 5th pair, on the other hand, are slender 

 and comparatively short, with a long slender carpopodite and with a 

 short propodite which with the strongly recurved dactylus forms a 

 sub-chela — all these joints being merely tomentose. The 5th pair of 

 legs is also remarkable for its sub-dorsal position. 



Length of carapace of an adult, 34 to 15 millim. 



Specimens in the Museum collection from the Laccadives, Maldives, 

 Ceylon, Andamans and Malay Peninsula, up to 32 fms. 

 29 



