3908] Bradleu. — Amphipods of the Genus Corophium. 235 



Leiijith, adult male. 14 nun.; adult female, 9.5 mm. 



Type locality. San Francisco Bay. 



East Oakland, San Francisco Bay. March 11, 1896; and 

 Alameda Beach, San Francisco Bay, Feb., 1893, collected by 

 Prof. J. S. Holmes. About two dozen specimens, mostly females 

 and some bearinji' eggs, in the collection of the University of 

 California. 



Corophmm salmonis Stimpson. 



Pis. 11, figs. 20-27; 12, figs. 28-35; 13, figs. 38, 39. 



Second antennae of the adult female (pi. 11. fig. 22) about 

 one-third longer than the first (pi. 11, fig. 23). Peduncle of the 

 first pair with the basal segment stout, one-third longer than the 

 second; third segment more than half as long as the second; 

 flagellum about two-thirds as long as the peduncle, the basal 

 segments but slightly shorter than those beyond. Second an- 

 tennae (pi. 11, fig. 22) stout, the basal segment with the lower 

 margin produced; the second segment bears no spines; penulti- 

 mate segment subcylindrical, a stout curved spine at the distal 

 end of the lower margin, without teeth above its apex, its lower 

 margin forming a distinct angle with that of the segment bearing 

 it; the ultimate segment cylindrical, one-half as thick as the 

 penultimate, lobed at apex, otherwise unarmed except* with 

 bunches of setae; flagellum one-third shorter than the ultimate 

 segment of the peduncle, two segmented, the apical segment bear- 

 ing two curved terminal spines and numerous setae. In the 

 young females the first antennae have a long spine on the inferior 

 margin of the first joint near the apex; the second antennae bear 

 no spines or processes except the ordinary lobe on the first seg- 

 ment and the apical hooks, they are rather short and tapering; 

 another female evidently somewhat older, bears a pair of spines 

 on the second segment of the second antennae, and one near the 

 base of the inferior margin of the third, another pair in the 

 position of the large curved spine of the adult. 



In the full grown male the second antennae (pi. 11. fig. 20) 

 are very long and stout, considerably longer than the entire body, 

 and two and one-half times as long as the first pair (pi. 11, fig. 



