6 A. Alcock — Carcinological Fauna of India. [No. 1, 



the antero-lateral borders cut into teeth which are from 5 (very rarely 

 4) to 9 in number (in Podophthalmus and some species of Euphylax, in 

 which the anfcero-lateral borders are excavated for the enormously pro- 

 lono-ed orbits, the number of teeth is reduced further). 



Front remarkably broad, generally well separated from the supra- 

 orbital angles, almost always cut into teeth or lobes, which are from 2 

 to 6 in number exclusive of the supra-orbital angles. 



The antennules fold transversely or obliquely transversely. 



Antennal flagella almost always long and slender. 



The epistome may be of fair length fore and aft, or may be linear 

 and sunken, but the palate is well defined anteriorly. 



Buccal cavern quadrate, commonly broader than long, the merua 

 of the external maxillipeds never decidedly elongate. 



The last pair of legs are, with few exceptions, modified for swim- 

 mino-, having at least the last two joints compressed, greatly broadened, 

 and paddle-like. ( In Caphyra and SpJiserocarcinus the last pair of legs 

 are much like the other three pairs, are subdorsal, and end in a hook- 

 like dactylus. In Carcinus, Nectocarcinus and Portumnus the dactylus 

 of the last pair of legs is merely lanceolate). 



I would propose to divide the Portunidas into four sub-families : — 



1. Sub-family Lupinse. The chelipeds are lona^er, usually much 

 longer, than any of the legs, the first three pair of which have a tendency 

 to be slender and the last pair of which end in typical swimming- 

 paddles: the antero-lateral borders of the carapace are cut into from 5 

 (very rarely 4) to 9 distinct teeth. The carapace may be subrotund, 

 but it is usually conspicuously broad. 



2. Sub-family Caphyrinse. The chelipeds and legs are short, but 

 the chelipeds are distinctly, if only slightly, longer than the legs. The 

 carapace is either as long as broad or very little broader than long, and 

 is either smooth or is traversed on either side by a single ridge running 

 inwards from the last of the (4 or) 5 teeth or puckers into which the 

 antero-lateral border is divided. The last pair of legs are either swim- 

 ming-paddles or are subdorsal and end in a prehensile dactylus. 



3. Sub-family Portunmae. The legs often have a tendency to be 

 stout, and at least one pair of them is at least as long as the chelipeds : 

 the last pair are typical swimming-paddles. The carapace is seldom 

 very broad and its antero-lateral borders are cut into 5 teeth. The 

 basal antenna-joint may be either fixed or movable : it is seldom broader 

 than long, often longer than broad, and lies almost in the longitudinal 

 axis of the carapace. 



4. Sub-family Carcininse. The legs have a tendency to be stout, 

 and at least one pair of them is at least as long as the chelipeds : the 



