50 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.18 



Uropod 1 reaching to end of or slightly beyond peduncle of uropod 

 2; rami equal in size, slightly shorter than peduncle; both margins of 

 inner ramus and outer margin of outer ramus spinulate. 



Uropod 2: rami equal in size, slightly shorter than peduncle; both 

 margins of inner ramus and outer margin of outer ramus spinulate, 

 apex of outer ramus with a long spine. 



Uropod 3: rami equal in size, long, slender, lanceolate; apex of 

 inner ramus setose, inner margin of outer ramus setose. 



Telson: apices of lobes pointed, notched on outer edge, apices with 



2 to 5 setae; dorsal surface of each lobe with 4 to 6 setae. 



Pleon segment 3: posterior margin slightly convex, lower posterior 

 angle produced into a large tooth. Dorsal surface of segment may be 

 slightly cristate. 



Pleon segment 4: posterior dorsal surface with a saddle-shaped 

 carina, posterior margin vertical. 



Pleon segment 6 with low lateral crests. 



Length of female, 16 mm. 



Male: Differing from the female by the deeper notch of segment 4 

 between segment 3 and the dorsal carina, by the more shallow saddle- 

 shape of the carina ; rami of uropod 3 broader than in female ; antennal 

 peduncles with setal tufts; telson slightly broader than in female; and 

 rostral area of head slightly more produced. Length of male, 1 1 mm. 



Material examined: Stations 696-37 (14), 706-37 (1), 711-37 

 (2), 713-37 (1), 893-38 (6), 981-39 (6), 985-39 (1), 1022-39 (2), 

 1026-39 (1), 1031-40 (1), 1140-40 (1), 1150-40 (5), 1151-40 (1), 

 1168-40 (4), 1169-40 (8), 1173-40 (3), 1191-40 (2), 1194-40 (7), 

 1202-40 (3), 1245-41 (1), 1260-41 (1), 1295-41 (8), 1316-41 

 (1), 1328-41 (1), 1353-41 (1), 1359-41 (2), 1384-41 (16), 1387-41 

 (10), 1388-41 (2), 1390-41 (16), 1402-41 (1), 1418-41 (9), 1938- 

 50 (1). 



Remarks: In young material (7-9 mm), the apical notches of the 

 telson lobes possess only 3 to 4 setae, and the dorsal surface of each 

 lobe has only 2 setae; the depression on the carina of pleon segment 4 

 is very shallow. 



Stimpson probably described this species on the basis of male speci- 

 mens, for he notes the presence of a deep notch between pleon segment 



3 and the dorsal carina of pleon segment 4. Holmes described a new 

 species, Ampelisca californica, which he differentiated from A. pugetica 

 by the shallow notch between segment 3 and the carina of segment 4 

 of the pleon. Holmes also described a male of the species, but he prob- 



