410 A. Alcock — Carcinological Fauna of India. [No. 3, 



The orbits, which occupy tlie rest of the anterior border of the 

 carapace, are oval and of good depth : below their outer angle is a deepish 

 gap leading into a system of grooves which open into a notch at the 

 antero-lateral angle of the buccal cavern. At the inner angle of the 

 orbit is the usual tooth, belonging to the inner of the two fossae into 

 which (as in all the crabs of this subfamily) the orbit is so plainly 

 divided. The eyes are of no great length. 



The antennules fold nearly transversely into rather narrow fossae : 

 the inter-antennular septum is very broad. 



The antero-external angle of the 2nd joint of the antennal peduncle 

 is a good deal produced : the antennal flagellum, which is slender and 

 rather short, lies in the orbital hiatus. 



Epistome well defined, prominent, rather short fore and aft. Buccal 

 cavern square. The external maxillipeds leave between them a large 

 rhomboidal gap, which is a good deal filled up by a hairy fringe : they 

 are obliquely traversed, from a point behind the antero-external angle 

 of the ischium to the antero-internal angle of the merus, by a conspi- 

 cuous line or crest of hairs : the palp, which is rather coarse, is 

 attached to the rounded summit of the obliquely-directed merus. 



Chelipeds massive — not always so in the female — usually subequal, 

 of no great length : palm high and short, the fingers though subacute, 

 are hollowed at the tip. 



The legs do not usually differ very markedly in length, though the 

 third pair are the longest and the first and last (4th) pairs the shortest : 

 the meropodites are thin, and are usually, but not always, broad. 



The abdomen in both sexes consists of 7 separate segments : in the 

 male it occupies the whole breadth of the sternum between the bases of 

 the last pair of legs. In both sexes the second segment, as well as the 

 exposed portion of the first, are narrow fore and aft. In the female 

 the last segment is small and narrow from side to side, and is more or 

 less impacted in the broad 6th segment : in the male also the last seg- 

 ment is much narrower than the one that precedes it. 



Distribution : all tropical and subtropical seas : not found in the 

 Mediterranean. 



I am not inclined to adopt the subgenera proposed by Dr. de Man, 

 although I must admit that his system is convenient in practice, for 

 identifying species. 



I may also mention here that specific distinctions based merely 

 on the sculpture of the dactylus of the male chelae are inadmissible, 

 as the sculpturing frequently differs in the two fingers of the same 

 individual. 



