100 U.S. NATIONAL MUSEUM BULLETIN 2 60 



straight, article 3 much shorter than article 2, palp moderately setose, 

 article 2 straight, molar cup shaped, small, one side of cup-rim with 

 long cusps ; inner lobes of lower lip separated ; inner plate of maxilla 



1 with two setae, outer with nine spines ; coxa 1 moderately expanded 

 ventrally; fourth articles of gnathopods with acute apicoposterior 

 cusp, fifth articles produced to short lobes of medium breadth, lobe on 

 gnathopod 2 distinctly guarding article 6 and extending about one 

 third along posterior edge of article 6 ; pahn and posterior margin of 

 article 6 on gnathopod 1 subequally long, palm about three fourths as 

 long as posterior margin of article 6 on gnathopod 2, latter article 

 elongated ; pereopods 1 and 2 similar to each other, article 4 with mid- 

 lateral row of setae, article 5 not differentially expanded in comparison 

 with article 6, latter slightly narrower than fifth but not distinctly 

 slender, dactyl saber shaped, stout; dactyls of pereopods 3-5 (dam- 

 aged) also saber shaped; telson apically truncate, slightly convex, 

 armed with two slender, medial setae, and various lateral setae. 



HoLOTTPE. — AHF No. 6126, male, 8.0 mm. Unique. 



Type-localitt.— Station 7358, 27°35'45'' N, 115°08'30'' W, 1095- 

 1205 m, Apr. 21, 1961. 



Relationship. — According to the foregoing key this species has its 

 closest resemblance to Aceroides Jcohjakovae Bulycheva (1952). The 

 two species have poorly developed posterior lobes on the fifth articles 

 of gnathopod 1 and differ from each other in the gnathopodal palms 

 and length of fifth articles of gnathopod 2. They also differ by the 

 condition of article 2 of the mandibular palp, as stated in the key; 

 this variable is one used elsewhere in the Oedicerotidae to distinguish 

 genera, e.g., Batliyinedon Sars and Westwoodllla Bate. 



Aceroides edax, new species 



TiGUEES 45, 46 



Diagnosis. — Rostrum almost completely absent ; anterolateral ceph- 

 alic margins nearly straight, poorly produced, broad in holotype, but 

 with well-developed quadrate lobes in other specimens; eyes absent; 

 epistome-labrum with blunt anterior cusp, with slight notch in re- 

 tarded dorsal portion above cusp; mandibular palp straight, articles 



2 and 3 equal in length, palp moderately setose, article 2 straight, 

 molar cup shaped, small, one side of cup-rim with long cusps; inner 

 lobes of lower lip separated ; inner plate of maxilla 1 with three setae, 

 outer with eight spines; coxa 1 moderately expanded below; fourth 

 articles of gnathopods with blunt apicoposterior process, fifth articles 

 produced to long slender lobes, lobe on gnathopod 2 distinctly guard- 

 ing article 6 and extending along posterior edge nearly to defining 



