12 ^. Alcock — Carciiiological Fauna of India. [No. 1, 



Subfamily I. CARCININ^. 

 Carcinus, Leach. 



Carcinus, Leach, Malac. Podophth. Brit. Text of pi. V. : Desmarest, Consid, 

 Gen. Crust, p. 90: Milne Edwards, Hist. Nat. Crust. I. 433 : De Haan, Faun. Japon. 

 Crust, p. 13 : Bell, British Stalk-eyed Crust, p. 75 : A, Milne Edwards, Ann. Sci. 

 Nat., Zool., (4) XIV. 1860, pp. 228, 266; and Archiv. du Mns. X. 1861, p. 390. 



Carcinides, M. J. Rathbun, Proc. Biol. Soc. Washington XI. 1897, p. 164 {new 

 name pr-oposed) . 



Carapace approacliing the hexagonal, not broad, slightly but dis- 

 tinctly convex, the regions fairly well-defined (well-defined for a 

 Portunoid), no distinct transverse ridges. 



Front proper fairly well defined from the inner supra-orbital angles 

 beyond which it projects slightly, three lobed, between a fourth and a 

 fifth the greatest breadth of the carapace in width. 



Antero-lateral borders thin, oblique, arched, cut into five teeth 

 including the outer orbital angles, shorter than the postero-lateral 

 borders. 



Orbits with one faint notch in the upper and one in the concave 

 lower border, the inner angle of the lower border dentiform but not 

 very prominent. The antennules fold obliquely, but nearer the trans- 

 verse than the longitudinal. 



Basal antenna- joint slightly longer than broad, fixed ; the flagellum, 

 which is not very long, stands in the orbital hiatus. 



Buccal cavern square, its greatest length a little more than its 

 greatest breadth : the external maxillipeds are rather elongate, espe- 

 cially the merus which projects somewhat beyond the level of the edge 

 of the endostome : epistome lozenge-shaped. The ridges that define 

 the efferent branchial canals do not approach the edge of the endostome. 



Chelipeds massive, just shorter than any of the first three pairs of 

 legs, slightly unequal : arm short, without any spines : inner angle of 

 wrist alone spiniform : no spines on the hand, which is deep and not 

 prismatic : fingers stout, a little shorter than the palm, not very strong- 

 ly toothed. 



Legs stoutish : the last pair have the merus elongate and unarmed, 

 the carpus not dilated, the propodite shortened and somewhat broad- 

 ened, and the dactylus acutely lanceolate. 



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

 being fused. 



Carcinus exhibits the relation of the Portunidae to other Cyclo- 

 metopan families, being related to Pirimela among the Cancridae and 

 to Hoploxanthus among the Xanthid^. 



