No. 26.] ARTHROSTRACA OF CONNECTICUT. 13! 



Length 7 mm. 



Very abundant in streams, lakes, and stagnant pools through- 

 out the entire United States. New Haven and Canaan, 

 Connecticut. 



Allorchestes Dana. 



First antennae longer than peduncle of second. 



First maxillae with uniarticulate palp. Maxillipeds with four- 

 jointed palp. 



Second gnathopods in male with carpus produced behind 

 between the adjacent segments. 



Telson more or less divided. 



Allorchestes littoralis Stimpson. 



FIG. 37. Allorchestes littoralis. 



1853. Allorchestes littoralis, Stimpson, Marine Invert. Grand 

 Manan, Smithson, Contrib. Knowl., vol. 6, No. 5, p. 49, pi. 3, 

 %. 36. 



1874. Hyale littoralis, Smith, Rep. Com. Fish., vol. I, p. 556. 



Eyes oval, moderately large, situated rather close together. 



First antennae three-fourths the length of second with the 

 three joints of peduncle of subequal length; flagellum longer than 

 peduncle and made up of nine to thirteen joints. Second antennae 

 less than half the length of body, last joint of peduncle slightly 

 longer than preceding one, the lower side furnished with a large 

 tuft of plumose spines. 



First gnathopods much alike in the two sexes ; merus pro- 

 duced distally into a prominent setose angle ; carpus with posterior 

 lobe oblong, rounded, and thickly setose ; propodus oblong, widen- 



