No. 26.] 



ARTHROSTRACA OF CONNECTICUT. 



203 



Pleopods well developed, adapted for swimming and respira- 

 tion. Second pair of pleopods in the male with a stylet inside the 

 inner plate. Uropods lateral, and forming with the well developed 

 terminal segment of the abdomen a caudal fan. 



Cirolana concharum (Stimpson), 



Fig. "60. Cirolana concharum. 



1874. Co nil era concharum, Harger, Rep. U. S. Com. Fish, 

 for 1871-2, p. 572. 



1880. Cirolana concharum, Harger, Rep. U. S. Com. Fish, 

 for 1878-9, p. 378, pis. 9 and 10, figs. 58-63. 



Body three times as long as broad. Head quadrate, wider than 

 long, anterior margin rounded, embraced at the sides by first 

 thoracic segment. Eyes small, triangular and with angles 

 rounded. 



First antennas robust, arising immediately beside each other; 

 first and second segments subequal, each one-half as long as 

 third joint; flagellum robust, tapering, consisting of about fifteen 

 joints. Second antennae longer and more slender than first pair, 

 not in contact with each other at origin; first and second joints 

 short and subequal ; third and fourth subequal and each as long 

 as two preceding together; fifth joint a little longer than fourth; 

 flagellum composed of about sixteen joints. 



Mandibles robust, palp slender and triarticulate, with the 

 second segment the longest and setose on inner margin beyond 

 the middle, last segment slender and curved. Maxillipeds 

 elongated and almost pediform but flattened; palp five-jointed 

 with last four joints flat, broad, and densely setose. 



