8 U.S. NATIONAL MUSEUM BULLETIN 260 



Material.— Stations 7235 (1), 7358 (1). 



Remarks. — This subspecies is clearly derived from the nearby 

 coastal shelf population and parallels other cases such as Ampelisca 

 macrocephala unsocalae, Heterophoxus oculatus (Holmes) and various 

 species of Listrlella in its loss of eyes and slight modification of other 

 characters. 



Distribution. — Middle Baja California, 1205-1248 m, 



Ampelisca species 



Figure 2 



Description. — Interantennal cephalic lobe projecting subacutely, 

 anterior cephalic margin ventral to lobe oblique but not strongly so ; 

 corneal lenses absent; antenna 1 extending to apex of peduncle of 

 antenna 2, article 2 of peduncle about 1.4 times as long as article 1, 

 article 3 about one third as long as article 2, flagellum scarcely half 

 as long as peduncle and composed of 4 long articles; antenna 2 

 scarcely half as long as body, flagellum slightly longer than peduncle, 

 articles of flagellum elongated ; coxa 1 with conspicuous posteroventral 

 notch, coxae 2 and 3 with rudimentary notches; pereopods 1 and 2 

 very slender and poorly setose, dactyls longer than articles 5 and 6 

 combined; pereopods 3-5 poorly setose, fifth articles of pereopods 



3 and 4 slightly produced posterodistally, lacking submarginal pos- 

 terior spines ; posterior lobe of article 2 on pereopod 5 extending sub- 

 quadrately to distal end of article 4, distal margin bearing one or no 

 setae, anterodistal margin of lobe bearing one or no setae (both 

 setae are illustrated on pereopod 5 but the appendage on either side 

 of the unique holotype bears only one or the other of the setae) ; article 



4 of pereopod 5 slightly longer than article 3, articles 3-7 slender, 

 decreasing in width consecutively, articles 5-7 decreasing slightly 

 in length consecutively; third pleonal ej^imeron with nearly straight 

 posterior margin, posteroventral corner produced into tooth of medium 

 size; pleonite 4 with dorsal process nearly obsolete; uropod 1 slender, 

 reaching distal end of uropod 2, rami equal in length, unarmed 

 dorsally; uropod 2 slender, outer ramus shorter than imier, outer 

 ramus with one, inner ramus with two dorsal spines ; uropod 3 slender, 

 rami subequal, lanceolate, poorly setose; telson asymmetrical (possi- 

 bly scarred), one apex with acute medial cusp, other apex broadly 

 subacute, each apex with two short setae. 



Material.— Station 7358, ?male, 2.4 mm. 



Kelationship. — This specimen closely resembles Ampelisca ambly- 

 opsoides J. L. Barnard (1960a) and may be its ecotype or its juvenile. 

 Adults of A. amblyopsoides reach 9 mm in length. The distinguish- 

 ing characters of the unique specimen, such as the sparse setae and 



