No. 26.] 



ARTHROSTRACA OF CONNECTICUT. 



121 



Second pair with slender peduncle not as long as flagellum, fourth 

 joint two-thirds as long as fifth. 



First pair of coxal plates quadrate and as long as high. 



First gnathopods of male -as in preceding species. Second 

 pair with large oval propodus, having palm very oblique, evenly- 

 convex and spinous, and with a slight process at posterior end 

 against which the tip of the dactyl fits. In female, first gnatho- 

 pods similar to those of 0. agilis ; second pair with basal joint 

 somewhat broader and more rounded in front but otherwise 

 very much like the preceding species. Pereiopods four and five 

 with carpus slender even in the largest males. 



Fig. z^- Orchcstia palnstris. 



Postero-lateral angles of second and third abdominal segments 

 produced into acute points. 



First uropods with rami shorter than peduncle ; second pair 

 with rami equal to peduncle; terminal pair with a single ramus 

 which is longer than the peduncle and relatively larger than in 

 O. agilis. Telson bearing a posterior notch, lobes rounded and 

 spinous. 



