214 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



at the tip; first pair with carpus short and triangular and ischium 

 and merus with long setae on upper margin ; second and third pairs 

 with longer carpus. 



Abdomen composed of two segments ; the first one of which 

 resembles the last thoracic segment but is marked at the sides by 

 two depressions indicating sutures. Telson long and widely 

 rounded posteriorly, rather strongly contracted laterally at inser- 

 tion of uropods. 



Uropods extending beyond end of telson; inner ramus with 

 smooth margins ; outer margin subequal to the inner in length 

 and width, with three or four wide serrations on outer margin. 



Color extremely variable, some individuals of a uniform slatey 

 gray ; many marked dorsally with a whitish, creamy, or pinkish 

 patch margined with black. 



Length 8 mm. 



Distribution : Florida ; Georgia ; Virginia ; Beaufort, North 

 Carolina ; Great Egg Harbor, New Jersey ; Savin Rock, near New 

 Haven, Stony Creek, Connecticut ; Provincetown, Massachusetts ; 

 Vineyard Sound. 



It is found in abundance under stones or creeping about the 

 branches of seaweeds from low- water mark nearly to high-water 

 mark. 



When disturbed this species curls itself up into a ball with 

 facility and drops to the bottom. By this habit of rolling itself 

 into a ball it may be distinguished from all other marine Isopoda 

 of the coast. 



IDOTHEOIDEA or VALVIFERA. 



First thoracic legs not cheliform. 



Uropods lateral, situated ventrally and opening and closing 

 like valves over the five pairs of branchial pleopods ; and attached 

 on the outer margins to the terminal abdominal segment. 



IDOTHEID^. 



Body more or less depressed, with segments of thorax of 

 uniform appearance. First pair of antennae with uniarticulate 

 flagellum. Second antennae with flagellum uni-or multiarticulate. 



Mandibles without palp. 



