1896.] A, Alcock — Car etiological Fauna of India. 273 



being covered with large polished pearly granules polygonal by mutual 

 appression; its hairy distal end is suddenly depressed and does not 

 fall much short of the front edge of the afferent branchial canal : the 

 ischium is grooved along its inner border, bub the rest of its surface is 

 tumid and granular just like the exognatb. 



In the Indian Museum collection is a single female with the cara- 

 pace 17 millim. long by 42 millim. in extreme breadth, from 23 fathoms 

 off the Orissa Coast. 



I believe that this species must be Leach's Ixa inermis, as it cor- 

 responds with Leach's figure. Unfortunately the mouth-parts are 

 not figured or described. They are most characteristic in this species, 

 which cannot be mistaken for /. cylindrus. 



Family DORIPPID^E. 



Dorippiens, Milne Edwards, Hist. Nat. Crust. II. 151 (partim). 

 Dorippidea, De Haan, Faun. Japon. Crusb. p. 120. 

 Dorippidae, Dana, U. S. Expl. Exp. Crust, pt. I. p. 390. 

 Dorippidse, Miers, Challenger Brachyura, p. 326. 



Carapace flat, generally broadest behind near the plane of the 

 posterior border, hiding not much more than half of the abdominal 

 terga, the first three of which are commonly visible in a dorsal view 

 quite uncovered. The orbits are somewhat incomplete. The antennules 

 are commonly too large to fold inside their fossettes. The antenna? are 

 large. The mouth-parts somewhat resemble those of the Oalappidse : 

 the buccal cavern is prolonged forwards to form an efferent branchial 

 canal which is covered in below by a long lamellar process of the first 

 maxillipeds. The first two pairs of true legs are remarkably long and 

 stout : the last two pairs on the contrary are remarkably short and 

 slender, and occupy a singular position in the dorsal plane of the body. 

 The position of the afferent branchial canal varies. The vasa deferentia 

 perforate the 5th thoracic sternum on either side. The branchiae are 

 less than nine in number on either side. 



The Dorippida? may be divided into two sections or subfamilies as 

 follows : — 



1. Dorippinas, in which the external maxillipeds leave a consider- 

 able part of the buccal cavern uncovered, and in which the afferent 

 branchial openings are situated either immediately or shortly in atlvance 

 of the bases of the chelipeds. 



2. Tymolinse, in which the external maxillipeds almost completely 

 cover the buccal cavern, and in which the afferent branchial openings 

 may or may not be situated near the bases of the chelipeds. 



J. ii. 35 



