232 A. Alcock — Carcinological Fauna of India. [No. 2, 



to a stout tooth at the angle of the buccal frame, the antero-lateral 

 margin bears four large spines : of these, one, situated on the pterygos- 

 tomian region, is turned downwards to assist in forming a pterygos- 

 tomian canal somewhat similar to that of Docha canalifera, etc. : of the 

 other three, which are situated on the branchiostegal region, the last 

 is by far the longest and stoutest — being from one-third to half the 

 length of the carapace — and is directed a little backwards and upwards. 

 Down the middle line of the carapace runs a row of spines, increasing 

 in size from before backwards to the last, which, situated on the poste- 

 rior border, consists of two branches, one branch directed vertically 

 upwards, the other directed horizontally backwards, the horizontal 

 branch being often half the length of the carapace proper. 



On the anterior part of the branchial region, midway between 

 the middle line and the lateral border of the carapace, is a stout spine, 

 visible without any denudation. 



The chelipeds in the adult male are equal in length to the carapace 

 and l'ostrum, and have the hands much broadened, inflated, and very 

 elegantly carinated along the lower border, and the fingers evenly den- 

 ticulated but not closely apposable in all their extent. In the female 

 the chelipeds are not much more than half as long as the carapace plus 

 rostrum and posterior spine, and are rather slenderer than the other legs, 

 the fingers also being closely apposable throughout. In young males, of 

 the size figured by Mr. Walker, the enlargement of the hands is much 

 less marked than in old males. 



The second pair of trunk-legs, which are the longest, are from twice 

 to 2| times the length of the carapace measured from the base of the 

 rostrum to the base of the great postero-median spine. 



The sternum in the male has a pair of sharp teeth on its first seg- 

 ment. 



The abdomen in both sexes consists of seven separate joints. 



Colours in life : dull chocolate, spines white-tipped, chelipeds ivory 

 tinged svith pink, legs brownish pink with bright red dactyli. 



This species, of which we have a very fine old male, two younger 

 males of different sizes, an adult female, and a young female, appears to 

 be extremely close to D. calcitrapa, White (Proc. Zool. Soc, 1847, p. 56 ; 

 Ann. Mag. Nat. Hist., Vol. XX. J 847, p. 61 ; and ' Samarang ' Crustacea, 

 p. 7, pi. i. fig. 2). It appears to differ from D. calcitrapa only in the 

 proportions of the legs, which are slender and very long in the last- 

 named species. 



It may be mentioned that the rostrum and great spines of the cara- 

 pace are, judging from the state of two of our specimens, liable to be 

 broken and only very imperfectly repaired again. 



