158 Proceedings of the Biological Society of Washington. 



to the lower end of the fifth joint. Second gnathopod and first and 

 second peraeopods have styliform accessory branchal vesicles. Epistome 

 projecting forward beyond the lip in an evenly rounded curve. Mandibles 

 long and narrow with palp situated back of the middle. Cutting-edge 

 curved inward with edge smooth. Lobe projecting forward just above 

 the cutting-edge. Three setae situated between the cutting-edge and the 

 small backward-pointing tooth. First maxillae, inner plate narrow with 

 several small setae at apex. Outer plate with six large teeth, serrated on 

 their inner edge. Second joint of palp long with end gently curved and 

 crenulate. The palp is concave and fits around the outside of the outer 

 plate. The plates of the second maxillae are narrowly oval and armed 

 at their upper ends with spines. Maxillipeds, inner plates narrow, armed 

 on the upper third of their inner edge with setae, one or two small spines 

 on their upper ends. Outer plates broad and oval, seven or eight small 

 spines on their inner edge, crenulate on upper part of inner edge. 

 Fourth joint of palp dactyliform. First uropods longest. Rami styli- 

 form, somewhat shorter than peduncle, outer slightly longer. A few 

 spines on upper surface of peduncle and rami. Second uropods shorter 

 than first. Rami subequal, inner ramus with constriction containing 

 small spine about one-third the distance from the end. Third uropod 

 shortest, rami shorter than peduncle, outer ramus longer. Peduncle 

 with upper posterior angle quadrate and produced. Telson short, sides 

 slightly convex, end very obtuse angled with a small spine on each side 

 midway between apex and side of telson. 



Length. — 5 mm. 



Locality. — Venice, Southern California. 



Type.— Cat. No. 49596, U. S. N. M. 



Family Ampeliscid^. 

 Ampelisca venetiensis new species. 



Male. — Eyes four, upper pair very near front margin of head, lower 

 pair at lower anterior corner of head. First antennae reaching beyond 

 peduncle of second by about the length of last joint of second peduncle. 

 First joint short and thick. Second joint slenderer and about twice the 

 length of first. Third joint slenderer than second and a little shorter 

 than first. Flagellum about three times as long as peduncle and com- 

 posed of about 20 joints. Second antennae longer than body. Third 

 joint short, fourth and fifth successively narrower and subequal in length. 

 Flagellum very long and slender with many joints. The under surface 

 of the second joint of the first antennae and the upper surfaces of third, 

 fourth, and fifth joints of the second are provided with many tufts of fine 

 setae. The under surfaces of the first joint of the peduncle and the first 

 three or four joints of the flagellum of the first antenna are provided 

 with many fine setae. The lower posterior margin of the third abdominal 

 segment is broadly rounded and the middle, lateral margin deeply de- 

 pressed. The fourth abdominal segment is saddle shaped, having a deep 

 dorsal depression in the middle bordered at the front and back by promi- 



