1S96.] A. Alcock — Carciuological Fauna of India. 225 



The thoracic sinus is a deep liardly Y-shaped cavity, since the outer 

 limb of the Y is greatly produced and the inner limb is very short : the 

 tail of the Y is defined by two singularly large fungiform or reniform 

 tubercles with sometimes a third smaller one behind, and the strongly 

 convex edge of the pterygostomian region, which defines the thoracic 

 sinus in front, is finely milled. 



The front is prominent, almost quadrangular, ivith a sharply trans- 

 verse sinuous edge and with its dorsal surface, anteriorly, markedly concave. 



The ventral surface of the ischium of the external maxillipeds of 

 the female is broadly carinate up to a strong terminal tooth. 



The chelipeds, in the adult male, are very little longer than the 

 carapace. The arm is slender and is ornamented as in L. pallida : the 

 wrist is quite smooth : the hand, which is nearly twice as long as broad 

 and nearly twice the length of the fingers, has its outer edge carinate and 

 its inner edge sharp : the short fingers meet only at the tip, where 

 alone they are faintly denticulate. The legs are as in L. pallida. 



Colours in spirit : fawn colour, the front of the carapace sometimes 

 light olive-green ; four large round brown spots round the circumference 

 of the carapace behind ; two pale spots on either side of the gastric 

 legion. 



The carapace of the adult male is 14 millim. long and 11 millim. 

 broad ; that of the adult female is 13 millim. long and 1 1 millim. broad. 



A young male and 26 adults of both sexes (many of the females 

 with eggs) from the Andamans, are in the Indian Museum collection. 



55. Leucosia whitei, Bell. 



Leucosia whitei, Bell, Trans, Linn. Soc. Vol. XXI. 1855, p. 289, pi. xxxi. fig. 2, 

 and Cat. Lencos. Brit. Mus. p. 9 : Hess, Archiv fur Naturges. XXXI. i. 1865, 

 pp. 155, 172: Haswell, P. L. S., N. S. Wales, Vol. IV. 1879, p. 45, and Cat. 

 Austral. Crust, p. 118 : Miers, Zool. H. M. S. 'Alert,' pp.184, 289, and 'Challen- 

 ger' Brachyura, pp. 322 (footnote), 325: A. 0. Walker, Journ. Linn. Soc, Zool., 

 Vol. XX. 1890, p. 111. 



? Leucosia chevertii, Haswell, P. L. S., N. S. Wales, Vol. IV. 1879, p. 47, pi. v. 

 fig. 2, and Cat. Austral. Crust, p. 120. 



Carapace not appreciably longer than broad, elegantly urn-shaped ; 

 its surface smooth, except for (1) a narrow strip of thick short fur cloth- 

 ing its postero-lateral border, (2) a sharp angular granule-tipped emin- 

 ence springing from the vault of either hepatic region, and (3) a patch 

 of granules just dorsad of the lateral epibranchial angle ; its antero- 

 lateral border smooth as far as the front end of the thoracic sinus, and 

 then beaded ; its true postero-lateral border beaded as far as the level 

 of the base of the 2nd pair of legs (3rd pereiopods) ; its epimeral edge 

 visible in all its extent, dorsally ; its posterior margin gently curved. 

 J. ii. 29 



