NO. 1 BARNARD : AMPHIPODA OF THE FAMILY AMPELISCIDAE 15 



Peraeopod 1 rather stout, not greatly setose; article 4 produced 

 slightly at anterodistal angle, more strongly at posterodistal angle; 

 article 7 not much longer than articles 5 and 6 combined, nearly straight. 



Peraeopod 2: similar to 1 but with generic differences. 



Peraeopod 3 rather stout and short; articles 5 and 6 subequal in 

 length, article 5 with 2 sets of spines on posterior edge, article 6 with 

 2 spines on posterior edge. 



Peraeopod 4: similar to 3 but with generic differences. 



Peraeopod 5 very stout; lower posterior edge of lobe of article 2 

 oblique, lobe reaching downward to middle of article 4 ; article 4 much 

 longer than 3, very massive, posterior edge produced, setose; article 5, 

 anterior edge strongly notched ; article 6 attached to posterior proximal 

 portion of 5 ; article 7 short, stout. 



Uropod 1 extending as far as uropod 2, rami as long as peduncle, 

 inner ramus with 2 spinules on upper margin, outer margin of outer 

 ramus spinulate. 



Uropod 2: rami slightly shorter than peduncle, subequal in size, 

 upper edge of inner ramus and both edges of outer ramus spinulate. 



Uropod 3 short, stout ; rami very short, broad ; inner ramus slightly 

 larger than outer, apex with a few spinules and short setae; apex of 

 outer ramus notched. 



Telson : lobes rather narrow, apices blunt, notched, each notch con- 

 taining a blunt spine ; dorsal surface of each lobe with 2 blunt spines. 



Pleon segment 3 : posterior edge convex, posterior inferior angle 

 nearly quadrate. 



Pleon segment 4: posterior dorsal surface weakly convex, not pro- 

 duced above segment 5 at posterior end. 



Pleon segment 6: lateral processes small. 



Male: Differing from the female by the setal tufts on the antennae; 

 antenna 2 longer than body ; pleon segment 4 strongly rounded ; crests 

 of pleon segment 6 strongly developed ; rami of uropod 3 stout, lanceo- 

 late, inner ramus wider than outer, both rami strongly setose, apices 

 slightly recurved. Found only at Station 478-35. 



Material examined: Stations 12-33 (2), 113-33 (152), 244-34 

 (1), 257-34 (1), 264-34 (2), 287-34 (6), 364-35 (15), 374-35 

 (1), 398-35 (1), 448-35 (3), 459-35 (24), 478-35 (44), 487-35 

 (3), 555-36 (1), 556-36 (9), 562-36 (679). Laguna Beach, Cali- 

 fornia, intertidal, collected by John L. Mohr, April 17, 1947. 



Remarks: This species differs from Ampelisca lobata Holmes in the 

 shape of peraeopod 5 and in the form of uropod 3. 



