A NEW TYPE OF AlIPHIPODA. 123 



thick setge aloug the terminal margin ; the sixth joint is some- 

 what shorter and considerably more slender than the fifth ; the 

 claw (fig. 16, c.) is shaped as a moderately slender seta. 



Seventh Pair of Thoracic Legs (fig. 17). — These are slightly 

 longer than those of the fourth pair, with almost all the joints 

 considerably more slender, and deviate besides in the following 

 particulars : — The fourth joint is somewhat longer than the fifth, 

 with a long apical seta on the posterior margin ; the fifth joint 

 posteriorly on the end with a couple of short setse ; the sixth 

 joint is longer than the fifth ; the claw is setiform. 



Pleopods (fig. 18, pi.). — These are all equal as to shape and 

 size. Each pleopod consists of a moderately small, almost triangular 

 plate ; the three margins of the triangle do not differ much from 

 each other in length and all are a little convex ; setae are com- 

 pletely wanting, but at the postero-superior angle two feeble 

 serrations can be seen ; it is very movable, attached by the 

 anterior end which is a little truncate. This plate is homoloo-ous 

 with the long distal joint of the sympod ; the basal portion of 

 the sympod is absent in this species (in the following form it 

 consists of a distinct joint). 



Uropods (fig. 18). — The two anterior pairs are well developed, 

 each of them consisting of a peduncle and two rami. The 

 peduncle of the first pair is a little more than half as long as the 

 segment, rather compressed, with the basal half of the outer side 

 widened as a rounded wing ; the outer ramus is styliform, slender, 

 acute, and slightly shorter than the inner one ; the latter is 

 shaped as a very oblong plate, slightly shorter than the peduncle, 

 M ith about two longitudinal rows of long setse on the inner side 

 (fig. 19) near the upper margin, and terminating in four spiniform 

 processes arranged in a very oblique row. The peduncle of the 

 second pair is as long as its segment, somewhat longer and much 

 broader than that of the first pair, moderately compressed on 

 the distal half of its inner side, with four very oblique comb- 

 shaped rows of numerous slender spines (fig. 20), and a single 

 longer seta at the upper end of each of these rows ; the rami are 

 curved, acute styles, the outer one somewhat shorter than the 

 other, and both with a few setse on the proximal part. The third 

 pair of uropods are very small, almost rudimentary (fig. 18) ; 

 each (fig. 21) consists of two joints : the basal joint is short and 

 very thick, the other is many times smaller, rounded, terminating 

 in a single lo];ig seta. 



