No. 26.] ARTHROSTRACA OF CONNECTICUT. 113 



Eyes very narrow, reniform; pigment very dark. 



First antennae nearly half the length of the body; first joint 

 of peduncle as long as second and third combined; flagellum 

 more than twice the length of peduncle, composed of about 

 thirty-three segments ; accessory flagellum not quite half as long 

 as peduncle and composed of seven joints. Second antennae 

 considerably shorter than first, and having flagellum somewhat 

 longer than peduncle. 



Gnathopods not very strong, subequal in both sexes, those of 

 female having propodus oval quadrangular in form with palm 

 more oblique in first than in second pair; those in male a little 

 stronger, with propodus more oblong in form. Three posterior 

 pairs of pereiopods comparatively short and stout with outer 

 joints armed with fascicles of small spines. 



Fourth, fifth, and sixth segments of abdomen with three fas- 

 cicles of strong spines which are arranged in two rows converg- 

 ing above, each row arranged in two groups slightly apart. 



Last pair of uropods with outer ramus well developed and 

 coarsely spinous on both edges; inner ramus extremely small, 

 scarcely one-third as long as outer one, and narrow conical in 

 form. Telson comparatively small, each lateral half with one 

 lateral and three apical spines. 



Length 15 mm. 



Distribution: British Isles; coast of France; Mediterranean; 

 Vineyard Sound, Buzzards Bay; Woods Hole, Massachusetts; 

 Newport, Rhode Island ; New Haven, Noank Harbor, Connecticut. 



The species is found under stones below high-water mark 

 and is sometimes abundant. 



Carinogammarus mucronatus (Say). 



1818. Gammarus mucronatus, Say, Jour. Acad. Nat. Sci. 

 Phil., vol i, pt. 2, p. 376. 



1905. Carinogammarus mucronatus, Holmes, Bull. Bur. 

 Fish., vol. 24, p. 503, 



Eyes reniform. 



First antennas a little longer than second ; first joint of pedun- 

 cle longer than second, third joint three-fifths as long as preced- 

 ing ; flagellum twice as long as peduncle ; accessory flagellum com- 

 posed of three or four joints and not half as long as peduncle. 

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