1915-] Fauna of the Chilka Lake : Crustacea Decapoda. 275 



In U. longicaudata , Stimpson, the type species of the genus, and in its two near 

 allies, U. infraspinis, Rathbun, and U. indica, described below, the dactyli of the last 

 three peraeopods bear a slender inferior spine, thus differring notably from all 

 Periclimenes. In the two other described species of Urocaris, U. longipes, Stimpson, 

 and U. psamathe, de Man, forms which differ widely from the more typical repre- 

 sentatives of the genus, the dactyli are stated to be unarmed. In U. psamathe the 

 mandible has apparently not been examined and in both species we lack informa- 

 tion regarding the branchial formula. 



Urocaris indica, sp. nov. 



(Plate XIII, fig. 9.) 



? 1905. Urocaris longicaudata, Pearson (nee Stimpson), Rep. Pearl Oyster Fisheries, Ceylon, IV, p. 

 78, pi. i, figs. 5, 5a. 



The rostrum reaches almost to the end of the antennular peduncle. The upper 

 portion of the blade, that is to say that situated above the midrib, is deep and forms 

 a strongly arched crest rising above the general level of the carapace and armed 

 with 8, 9 or 10 more or less evenly spaced teeth. 1 The first of these teeth is situated 

 a little behind the orbit, while the second is immediately above it. The crest is 

 continued backwards as a well-marked carina for two-thirds the length of the cara- 

 pace and bears, a little in front of the middle point of the latter, a single isolated 

 spine. The portion of the rostral blade below the midrib is obsolete and the lower 

 edge is, in consequence, straight or even a trifle concave. This margin is unarmed 

 throughout the greater part of its length ; but, close to the apex and below, or in 

 front of the most distal tooth of the dorsal series, bears from 1 to 3 (usually 2) 

 minute teeth (pi. xiii, fig. 9). 



The carapace, except for the median carina noticed above, is smooth. It is pro- 

 vided with sharp antennal and hepatic spines and the sub-orbital angle is narrowly 

 produced and rounded at the extremity. 



The eyes are rather long, reaching almost to the end of the basal antennular 

 segment ; they possess a well-defined ocellus. 



The lateral process of the antennular peduncle (text-fig. 26a) has the form of a 

 sharp external spine situated at the proximal end. The outer margin in front of this 

 process is convex ; it bears a strong spine anteriorly and is continued forwards beyond 

 this to a point much in advance of the insertion of the second segment. The extreme 

 length of the basal segment is about twice that of the two following combined. The 

 outer antennular flagellum is distally divided into two unequal rami, the inner long 

 and slender, the outer stout and, including the basal fused portion, of a length equal 

 to that of the peduncle. The length of the stout outer branch is variable, but 

 usually less than half that of the fused portion. 



The antennal scale (text-fig. 266) reaches only a trifle beyond the antennular 

 peduncle. It is from three and a third to three and three quarter times as long as 



1 In one wholly abnormal specimen there are only five dorsal teeth. 



