AMPHIPODS FROM NORTH AMERICAN WEST COAST — SHOEMAKER 41 1 



Female. — Head, about as long as first 2 body segments combined; 

 rostrimi short, broadly triangular; lateral lobe rather narrowly round- 

 ing; eye more or less reniform, broader in some specimens than in 

 others, black or reddish brown in alcohol. Antenna 1 longer than 

 antenna 2; peduncle about as long as head, joints decreasing con- 

 secutively in length and thickness; second joint with shallow trans- 

 parent lobe on inner distal end ; flagellum long, slender, composed of 

 40-46 joints. Antenna 2, second joint with well-developed gland 

 cone; fourth joint slightly shorter than fifth, flagellum composed of 

 28-30 joints. Mandibles with toothed cutting-edge. Left mandible 

 with broad accessory plate and spine-row of 8 short broad spine- 

 teeth. Right mandible with accessory plate narrower than in left, 

 spine-row of 8-9 spine-teeth. Molar on both mandibles conical with 

 small triturating surface. Mandibular palp short, stout, third joint 

 slightly longer than second. Maxilla 1, inner plate short, bearing 1 

 distal plumose seta; outer plate with 9 pectinate spine-teeth; second 

 joint of palp armed distally with 7 spine-teeth, below which, on inner 

 margin, are several spines, inner surface with oblique row of 3 long 

 curved subdistal spines, outer surface with row of 5 long curved spines 

 near inner margin. Maxilla 2, inner plate slightly shorter but wider 

 than outer plate; both armed distally with usual spines, inner plate 

 with stout plumose seta on inner margin. MaxUliped, inner lobe reach- 

 ing to base of outer lobe, armed on truncate distal edge with 4 curved 

 spines and 4 very small spine-teeth; outer lobe not reaching middle of 

 second joint of palp, inner margin without spine-teeth but with sub- 

 marginal row of spines arranged in pairs; palp rather short, thick, 

 fourth joint as long as third. 



Coxal plates 1-4 slightly deeper than their body segments, lower 

 margins evenly rounding, first 3 bearing at hind corners small tooth 

 preceded by notch containing a setule. Coxal plate 1 slightly ex- 

 panded distally, produced slightly forward. Gnathopods 1 and 2 

 much alike but 2 larger; second joint slightly expanded distally but 

 not produced; fourth joint in gnathopod 2, but not in gnathopod 1, 

 ending distally in small point; sixth joint with front and hind margins 

 about equally convex; palm very oblique, without defining angle 

 but defined by 2 groups of spines, edged with narrow transparent 

 lamella, row of many short spinules, 3 groups of longer spines, and 

 bearing near distal hinge low tooth more conspicuous in gnathopod 

 2 than in gnathopod 1. Third joint of gnathopods 1 and 2 with 

 transparent downward-pointing lobe on front margin. Pereopods 

 1 and 2 much alike, subequal in length; fourth joint produced down- 

 ward in front; fifth joint shorter than fourth or sixth; sixth slightly 

 longer than fourth; seventh joint stout, curved, about K length of 



