No. 26.] ARTHROSTRACA OF CONNECTICUT. 24! 



Antennae minutely hirsute, especially on the flagellum, extend- 

 ing to posterior margin of third thoracic segment; first segment 

 short ; second twice as long as first ; third segment as long as the 

 second, clavate ; fourth nearly twice as long as the third ; fifth 

 longer than fourth ; flagellum composed of three nearly equal 

 joints ; the terminal one of which is tapering. 



First thoracic segment longer than the succeeding ones which 

 are subequal ; anterior angles of first segment somewhat produced 

 at the sides to embrace the posterior part of the head ; second and 

 third segments with their posterior angles less broadly rounded 

 but not produced backward at all; fourth, fifth, and sixth seg- 

 ments with posterior angles increasingly produced toward the 

 posterior end and acute. Legs all ambulatory and increasing in 

 size and length to the last pair. 



Abdomen abruptly narrower than the thorax, two-thirds as 

 wide as the last thoracic segment ; first two segments with lateral 

 lamellae nearly concealed by the seventh segment of the thorax; 

 lateral lamellae of the three succeeding segments not large, acute. 

 Telson acute but not prolonged behind and not extending beyond 

 the end of the peduncle of the uropod which is broad. Uropods 

 with rami originating at the same distance from the base; outer 

 ramus narrowly lanceolate, tapering to the tip and exceeding by 

 less than one-half its length the more slender, styliform inner 

 ramus. 



Color, dull and somewhat variable, usually brownish with light 

 lateral margins and narrow, median stripe separating the two 

 wide, dark bands. 



Length 8 mm. 



Distribution : Great Egg Harbor, New Jersey ; Freeport, Long 

 Island; Salem and Barnstable, Massachusetts; Vineyard Sound; 

 Stony Creek, Connecticut. 



This species is found under rubbish and stones on the shore 

 below high-water mark. Say states that it is " very common 

 under stones, wood, etc., in moist situations." 



Cylisticus convexus (DeGeer). 



1899. Cylisticus convexus, G. O. Sars, Crust. Norway, vol. 

 2, p. 186, pi. 81. 



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