19 



mid-clorsallj, the (1st) 2nfl and 3rd bluntly, incompletely and somewhat incon- 

 spicuously, the 4th— 6th very sharply and almost completely. The 5th ab- 

 dominal somite is about two-thirds the length of the 6th, the 6th is a little 

 shorter than the telson. The telson is shorter than the inner caudal swirameret, 

 and has no marginal spines. 



Eyes very large, slightly surpassed by the antennular scale. The outer 

 (upper) antennular Hagellum, which is slightly longer than the inner, is not 

 much more than half the length of its peduncle. 



The 3rd maxillipeds barely reach the middle of the antennal scale : their 

 dactylus in the male is not modified; but consists of a slender, setose, tapering 

 joint, about four-fifths the length of the propodite with which it articulate* 

 end-on. 



There is a strong antrorse spine on the basis of all three pairs of 

 chelipeds. 



In the adult male the last pair of thoracic legs has the proximal end of the 

 merus notched on its outer side, the notch being deepened anteriorly by a laro-e 

 retrorse and introrse, hook-like spine, and posteriorly hj a sub-terminal lobule 

 on the posterior border of the ischium. Beyond the spine the edo-'e of the 

 merus is finely denticulate in more or less of its extent. In both sexes the. 

 three terminal joints of these fifth legs are slender, and the dactylus rarelv 

 reaches much beyond the middle third of the antennal scale. No exopodite is 

 present on the fifth pair of legs. 



The andricum is quite symmetrical. In the adult it consists of two rio-id 

 segments tightly folded in all their length, interlocked all along their anterior 

 margin, and in close apposition along a great part of their posterior margin, so 

 as to form a compressed tul)e. Distally the tube ends in a pair of laro-e "-ar- 

 goyles, the posterior lips of which are convoluted like the mouth of a person- 

 ate corolla. 



The thelycum is concave, the hollow being bounded (1) laterally by a pair 

 of earhke lobes, the salient free edge of which is often incurved, and (2) ante- 

 riorly by a median tongue that [jrojects and is embedded between two lobes of 

 the sternum corresponding with the penultimate pair of legs. 



This species may attain, though rarely, a length of 6| inches. 



It is one of the commonest of the Indian prawns. In the Museum collec- 

 tion there are 281 specimens, registered as follows : — 



Pondicheny. Purchased. 



Sandlieads, R. Hooglilj-. .1. H. I'ow. 



Oris.sa coast. " Iiivestisjator." 



4585-4670 ,. , , 

 IJombay. I uichasetl. 



