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U.S. NATIONAL MUSEUM BULLETIN 271 



Sars, 1895, has the expanded article 6 of gnathopod 1 but coxa 1 

 tapers strongly to a subacute point and is partially covered by coxa 2; 

 the mandibular molar is like that of some species of Anonyx in its 

 sublaminar condition lacking teeth and ridges. The telson is deeply 

 cleft. Except for gnathopod 1 this species could be assigned to Uristes, 

 although Uristes has a mandibular molar more like that of Cheirimedon 

 crenatipalmatus. Cheirimedon latimanus also bears comparison to 

 Centromedon pumilus on technical grounds, and is very close to 

 "Tryphosa" auct. except for the first gnathopodal expansion. 



Figure 127. — Lysianassidae: Maxilla 1: a, Lysianassa heterodonta (Pirlot, 1936); b, 

 Bathyamaryllis perezii Pirlot (1933a); c, Trischizostoma nicaeense (Costa) (Sars, 1895, 

 pi. 12, as T. raschi) d, Hirondellea trioculata Chevreux (1900); e, Scopelocheirus crenatus 

 Bate (Sars, 1895, pi. 19);/, Lysianassa plumosa Boeck (Sars, 1895, pi. 16, as L. costae); 

 g, Acidostoma obesum (Bate) (Sars, 1895, pi. 14); h, Aristias neglectus (Bate) (Sars, 1895, 

 pi. 17); I, Orchomene batei Sars (1895, pi. 22). Maxilla 2: ;, Perrierella; k, Adeliella 

 laticornis Nicholls (1938); /, Orchomene; m, Trischizostoma; n, Acidostoma; o, Scopelocheirus; 

 p, Lysianassa plumosa. Coxa 1: g, Anonyx nugax (Phipps) (Sars, 1895, pi. 31). Coxa 4: 

 r, Paralibrotus setosus Stephensen (1923). Gills: s, Ichnopus spinicornis Boeck (Sars, 

 1895, pi. 15). Pleonites 3-6 (5-6 fused), lateral: t, Crybelocyphocaris tattersalli Shoemaker 

 (1945a). 



