1898.] A. Alcock — Carcinological Fauna of India. 129 



regions delimited by broad shallow rather indistinct depressions and 

 having a slightly uneven but not definitely lobulated surface. 



The front is laminar and narrow ; it projects well beyond the supra- 

 orbital border from which it is separated by a deep notch, and is split 

 by a suture in the middle line. The orbital margin is broken by three 

 sutures or actual fissures, and the tooth at the inner angle of the lower 

 border is very prominent. 



The antero-lateral borders, which are a good deal longer than the 

 postero-lateral, are cut into from 4 to 8 lobes or procurved spines. 



The basal antennal joint has its outer angle produced and tightly 

 wedged into the internal orbital gap, which it fills; but the flagellum, 

 which is of good length, does not arise within the orbit but at the base 

 of this process. 



The outer border of the merus of the external maxillipeds is 

 oblique. 



The chelipeds, which, are very massive and rather long, are a little 

 unequal in the male : the fingers are very stout and strongly arched, 

 and they meet only at the tip, which is broad expanded and hollowed 

 out almost like a horse's hoof. 



The abdomen of the male is five- jointed, the 3rd-5th somites being 

 fused. 



Key to the Indian species of Etisus. 



I. More than four teeth on the antero-lateral border, exclud- 

 ing the external angle of the orbit : free edge of front 

 not convex : the process of the basal antennal joint com- 

 pletely separates the lower from the upper inner angle of 

 the orbit : legs spiny : — 



i. Seven or eight uneven unequal-sized claw-like teeth 



on the antero-lateral border E. dentatus. 



ii. Seven evenly arranged broad compressed procurved 

 teeth of almost uniform size on the antero-lateral 



margin E. utilis. 



II. Four teeth (excluding the external angle of the orbit) on 

 the antero-lateral border : free edge of front bow-shaped : 

 the tooth at the inner can thus of the orbit in contact 

 with the eave of the orbit beyond the tip of the process 

 of the basal antennal joint : legs not spiny E. lasvimanus. 



55. Etisus dentatus, (Herbst) Edw. 



Cancer dentatus, Herbst, Krabben, I. ii. 186, pi. xi. fig. 66. 



Etisus dentatus, Milne Edwards, Hist. Nat. Crust. I. 411 : Dana, U. S. Expl. 

 Exp. Crust, pt. I. 185, pi. x. figs. 2a-b : A. Milne Edwards, Nouv. Archiv. du Mus. 

 IX. 1873, p. 233 : Miers, P. Z. S. 1877, p. 134 : Richters in Mobius, Meeresf. Maurit. 

 J. ii. 17 



