No. 26.] ARTHROSTRACA OF CONNECTICUT. I53 



of setae on inner margin and with a two- jointed club-shaped 

 palp. Maxillipeds with four-jointed palp and plates well 

 developed. 



First five coxal plates large, first four oblong and first 

 not produced greatly anteriorly ; all much deeper than their 

 segments ; fifth coxal plate bilobed. 



Gnathopods of male- greatly elongated and provided with 

 abundant plumose setae, first pair as large as second; fourth joint 

 with posterior margin produced to form a rather slender triangu- 

 lar process which fits behind the very long subtriangular carpus ; 

 propodus oval, considerably smaller than carpus, palm oblicjue, 

 nearly straight and armed with a stout prehensile spine at the 

 rounded posterior angle, dactyl long and curved. Second gnath- 

 opods with merus and carpus smaller than in first; propodus 

 oblong, with a sinuous palm and posterior angle produced ; dactyl 

 shorter and stouter than in first. 



Gnathopods of female of nearly equal size and similar form, 

 much smaller than in male ; carpus as broad as, and longer than, 

 propodus which is narrowed at the proximal end and expanded 

 distally, palm oblique and rounded jx^steriorly where it is armed 

 with a spine. 



First pair of uropods with styliform rami ; nearly as long as 

 peduncle and provided with spines on upper margin ; peduncle 

 bearing a slightly curved prolongation distally below rami ; second 

 uropods with rami as long as peduncle ; third uropods with short, 

 stout rami the outer one of which is shorter than the inner and 

 provided distally with two strongly curved hooks ; inner ramus 

 about one-half as long as peduncle. 



Telson thick, triangular with rounded apex, provided with 

 several setae at distal corners. 



Color variable, about as in Amphithoe longimana. 



Length 12 mm. 



Stebbing (1906) erroneously, refers this species to the genus 

 Amphithoidcs Kossmann from which genus Gnibia differs by 

 having two well developed hooks on outer ramus of terminal 

 uropods and the terminal joint of mandibular palp not enlarged. 



The species occurs generally from Cape Cod southward to 

 North Carolina, being especially common in eel-grass. 



