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



Anterolateral borders shorter than the postero-lateral — a spinule 

 at their point of junction. 



Front somewhat deflexed, broad and broadly bilobed. Orbits 

 affording little or no concealment to the eyes, without fissures or 

 sutures : there is a gap between the front and the inner angle of the 

 orbit in which the antennary nagellum is lodged. The fron to- orbital 

 border, in the adult, is not quite |- the greatest breadth of the carapace. 



The antennules fold nearly transversely : the basal antennal joint 

 does not reach the front, the flagellum is a good deal longer than the 

 major diameter of the orbit. 



The buccal cavern is a little narrowed anteriorly. The crests of 

 the endostome are very faint, but to make up for this the anterior edge 

 of the buccal cavern is puffed out and is very deeply excised on either 

 side of the middle line ; the anterior margin of the foliaceous process 

 of the 1st maxillipeds is also excised to correspond, and so a permanent 

 expiratory orifice is formed, which is very large and prominent beyond 

 the almost transverse anterior edge of the merus of the external 

 maxillipeds. 



The chelipeds are stout, very long and not very unequal ; the whole 

 of the arm projects beyond the edge of the carapace : the fingers are 

 somewhat compressed and are pointed. 



The legs are rather slender. 



The abdomen of the male consists of five pieces, the 3-5th somites 

 being rigidly united but without obliteration of sutures. 



150. Sphenomerus trapezioides, Wood-Mason. 

 Sphenomerus trapezioides, Wood-Mason, Ann. Mag. Nat. Hist. March 1891, 

 p. 263: 111. Zool. Investigator, Crust, pi. v. fig. 2 (where the carapace is drawn a 

 little too broad). 



Carapace about -f as long as broad, convex in all directions, smooth, 

 polished. 



The front is about -f the greatest breadth of the carapnce, is obli- 

 quely deflexed, and is divided into two rather shallow broadly-rounded 

 lobes the free edge of which is entire. 



The supra-orbital angle is not defined, but the dentiform or spini- 

 form angle of the lower edge of the orbit can be seen from above. 



The antero-lateral margins form with the front a semicircular 

 curve, each carries three sharp spinules, namely, one at the outer angle 

 of the orbit, one at the junction with the postero-lateral border and one 

 exactly intermediate between the other two. 



The chelipeds are a little, but not very remarkably, unequal : the 

 larger one is about 2J times the length of the carapace. Their surface 

 is smooth and polished. The arm, the whole of which is visible beyond 



