No. 26.] ARTHROSTRACA OF CONNECTICUT. 69 



second and third joints with many fascicles of setse ; flagellum 

 long and slender. 



Coxal plate of first gnathopod projecting considerably ante- 

 riorly so that the mouth parts are hidden, lower margin serrate 

 and armed with setse; second joint very long and slender; carpus 

 longer than the propodus which is rectangular and three times as 

 long as broad, posterior margin with setse and stout spines ; dactyl 

 stout. 



Second gnathopods with rhomboidal coxal plate which is 

 provided with setas ventrally; carpus much longer than in first 

 pair; propodus similar to that of first pair. 



Fourth coxal plate incised posteriorly, about as long as high. 

 First and second pereiopods with spinning glands ; merus very 

 long and setose ; carpus and propodus short ; dactyl slender and 

 longer than propodus. Last pair of pereiopods with basal joint 

 expanded distally, posterior margin nearly straight, ventral 

 margin evenly curved and reaching as far as distal end of carpus 

 and provided with a fringe of setse ; carpus as long as ischium 

 and merus together, a little less than twice as long as broad, 

 spinous on anterior and distal margins ; propodus nearly as long 

 as carpus, nearly four times as long as broad, with two 

 transverse rows of spines and with distal margin having a long 

 spine on each side of base of the long, slender dactyl. 



Third abdominal segment with postero-lateral angles rounded. 

 Uropods biramous. First pair with equal rami, styliform and 

 slightly longer than peduncle which bears a number of short 

 spines dorsally. Second pair not extending as far as first ; outer 

 ramus shorter than inner. Third pair with equal rami which are 

 longer than the peduncle and extend as far as first pair, inner 

 margin of inner ramus provided with long setse, outer margin 

 serrate, outer ramus with inner margin serrate. Telson slightly 

 longer than broad, lateral margins evenly curved and converging 

 rapidly to the evenly rounded extremity, cleft for more than half 

 its length. 



In alcoholic specimens the coxal plates, bases of posterior 

 pereiopods and sides of the abdomen are provided with large, 

 irregular flecks of dark pigment. 

 Length 10-12 mm. 



