No. 26.] 



ARTHROSTRACA OF CONNECTICUT. 



155 



their segments, third pair the largest. Eyes round, situated on 

 the prominent interantennal lobes. 



Antenna; stout, their lower margins with long setae ; first pair 

 shorter than second pair, first joint of peduncle much shorter 

 than second which is a little longer than the third; flagellum not 

 much longer than last joint of peduncle, composed of five or six 

 joints; accessory flagellum minute, consisting of a single joint. 

 Second antennae very stout, with last joint of peduncle a little 

 longer than preceding one; flagellum about three-fifths as long 

 as last joint of peduncle. 



Fig. 46. Jassa mari)iorata. 



First gnathopods in both sexes with propodus ovate, palm 

 very oblique, with a row of three prehensile spines. Second 

 gnathopods with propodus enormously developed and produced at 

 proximal end of palm into a long, narrow, thumb-like process, 

 lower end of palm with a triangular process. In the female the 

 second gnathopods are much smaller than in the male, propodus 

 oval in outline, with front margin very convex and palm concave. 

 First and second pereiopods with merus much dilated and pro- 

 duced downwards in front. 



First uropods with peduncle having a large spine on the lower 

 margin nearly half the length of the rami. Last pair with rami 

 half as long as peduncle. Telson broader than long, apex rounded 



