Indian Deep-sea Dredging. 227 



spines decreasing in size from before backwards ; in the con- 

 cavity between these ridges is a faint median ridge running 

 np to tlie terminal spine of the rostrum. Jieliind tiie cervical 

 groove the cardiac region is traversed by a broad ridge sur- 

 mounted by a double row of spinelets, which diminish in 

 size from before backwards, the whole being an evident con- 

 tinuation of the rostrum. 



The under surface of the true rostrum behind the single 

 inferior sj)inc is furnished with a fringe of long sctaj, which 

 is continued round the orbital margin on each side. 



Laterally on the level of the antennae the frontal region 

 is occupied by a great trenchant wing-like spine, the point of 

 ■which surpasses the base of the antennary scale and reaches 

 almost to the anterior limit of the eyes ; between this spine 

 and the postrostral ridge on each side are three small spinules 

 disposed in a triangle. On the hepatic region, which is very 

 distinctly delimited, are two spines, a large one ventrally and 

 a small one dorsally. The cardiac and branchial regions are 

 very distinctly demarcated from the gastric and hepatic, the 

 two first forming a section of a much larger cylinder than 

 the two second. The cardiac region is traversed by the 

 already described continuation of the rostrum, and is bounded 

 on each side by a granular or finely spinate ridge. The 

 branchial regions are traversed fore and aft by two similar 

 ridges, one almost parallel with that last described, the other 

 following the curve of the thickened and grooved branchio- 

 stegal margin. All these ridges end anteriorly in minute 

 spines. 



The abdominal somites appear to correspond at all points 

 with those of Nephrops Thomsom'j Spence Bate, their terga 

 being sculptured in the same way, and the sixth somite and 

 telson being quite similar in spinature. 



The eyes are reniform and of huge size, their major 

 diameter being nearly half the length of the rostrum; the 

 peduncles are very short. 



The peduncles of the antennules are shorter than the 

 rostrum ; the first joint viewed from above is spoon-shaped, 

 the bowl forming the fioor of the orbit, and the distal end has 

 an inconspicuous spine below ; the second and third joints 

 are subcylindrical and are of nearly equal length, not much 

 more than one third of tlie first ; distully all three joints are 

 thickly ringed with long cilia ; the inner flagellum is more 

 slender and considerably longer than the outer, the length of 

 the former being three times that of the peduncle ; in the 

 male the outer flagellum has a row of fine setse in its distal 

 half below. 



