14 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 18 



The largest specimens of this species (11 mm) show a slight pro- 

 duction of pleon segment 3 into a small point at the posterolateral cor- 

 ner. This variation appears to depend only on the size of the specimens. 



Distribution: Widely distributed in the Channel Islands, off the 

 coast of southern California, 12 to 100 fms; along the coast of Lower 

 California at San Quentin Bay, Cedros Island, Santa Maria Bay, San 

 Carlos Point, and Thurloe Head, 2.5 to 30 fms; Gulf of California at 

 San Hipolito Bay, San Esteban Island, San Pedro Nolasco Island, and 

 Tortuga Island, shore to 75 fms ; south of White Friars Islands, Mexico, 

 25 fms; Port Parker, Costa Rica, shore; coast of Panama at Secas 

 Islands and Bahia Honda, shore to 14 fms; off Port Utria and Octavia 

 Bay, Colombia, shore to 20 fms ; south of La Libertad, Ecuador, shore ; 

 North Bay, Lobos de Afueras Islands, Peru, 12 to 22 fms; Galapagos 

 Islands, shore to 70 fms. 



Ampelisca schellenbergi Shoemaker 

 Plates 7 and 8 



Ampelisca schellenbergi Shoemaker (1933), Amer. Mus. Nov., no. 598, 

 pp. 3-5, figs. 1, 2; Shoemaker (1942), Smithsonian Misc. Coll., 

 vol. 101, no. 11, p. 9. 



Description of female: Head about as long as first 3 body segments, 

 anterior edge of head broadly incised, lower front edge oblique, convex. 

 Upper pair of eyes behind upper margin of antenna 1, lower pair just 

 below angle of lateral lobe of head. 



Antenna 1 stout, slightly longer than peduncle of antenna 2; first 

 and second articles of peduncle subequal, third slightly shorter. 



Antenna 2 about three fourths as long as body; peduncle short, 

 stout; article 5 three fourths as long as 4. 



Mandible: spine row with 9 spines; article 3 of palp about as long 

 as 2. 



Maxilla 1 : outer plate with 10 spines; apex of palp article 2 with 

 5 spines, 4 cusp teeth and 4 or 5 setae. 



Maxilliped: inner plate reaching to end of palp article 1, apex 

 with 2 chisel teeth ; outer plate reaching to end of palp article 2, inner 

 edge with 12 chisel teeth, rounded apex with 4 setal spines. 



Coxae 1 to 3 : lower posterior corner split. 



Gnathopod 1 : article 6 about as long as article 5, posterior margin 

 nearly straight ; article 7 rather strong, more than one half as long as 6. 



Gnathopod 2 not much longer than 1, article 5 shortened, article 6 

 about two thirds as long as article 5, article 7 strong. 



