No. 26.] ARTHROSTRACA OF CONNECTICUT. 235 



flagellum composed of about eighteen segments and reaching as 

 far as hind margin of fifth thoracic segment. 



First three thoracic segments subequal in length and longer 

 than the last four which are also subequal in length, except the 

 fifth which is shorter than the preceding. Lateral margins 

 sparsely setose and projecting so as to cover the basal joints of 

 the legs but coxal plates not distinct, lateral margins of first three 

 segments squarish, of fourth and fifth segments rounded, and 

 of last two segments obtusely angulated behind. Legs all of 

 similar form, ambulatory, but increasing in length behind. 



. Abdomen composed of a single joint which is setose on the 

 margin and rounded behind with a small median excavation for 

 the reception of the uropods. Uropods scarcely projecting be- 

 yond the general outline of abdomen, biramous, with short 

 stumpy peduncle and outer ramus about one-half as large as inner. 



Color very variable, commonly dark, slaty gray with dots or 

 small blotches of yellowish. 



Length, according to Harger, extremely variable, females 

 frequently bearing eggs when less than half the length' of speci- 

 mens figured which is about 7 mm. The males are at least one- 

 third smaller than the females. 



Distribution; North Sea; Baltic Sea; Greenland; Finland; 

 Denmark ; Scotland ; England ; Bay of Fundy ; Labrador ; East- 

 port, Casco Bay, Maine; Gloucester, Provincetown, Massachu- 

 setts, Vineyard Sound ; Noank Harbor, Stony Creek, New 

 Haven, Connecticut. 



This species is quite active in its habits and is found crawling 

 over rocks and barnacles, and especially beneath rocks and drift 

 wood, often nearly up to high-water mark. It is sometimes 

 found in the burrows of Limnoria. It has been noted by 

 McMurrich to breed from the middle of June to the first week in 

 September. 



It is distinguished readily from the other marine Isopoda of 

 Connecticut by the short uropods, arising from a notch at the 

 apex of the rounded abdomen and the multiarticulate flagellum of 

 the second antennae. 



BOPYROIDEA or EPICARIDEA. 

 First thoracic legs not cheliform ; uropods terminal, but some- 

 times pleopods and uropods are absent; when present pleopods 



