GAMMARIDEAN AMPHIPODA 137 



narrow, elongated lobes)) ; gnathopods with stout hands (like those 

 of P. kergueleni) , hands less than 1.5 times as long as wide, palms 

 oblique, convex, each defined by one large spined cusp; article 7 of 

 pereopod 5 slender, as long as article 6; coxa 4 subquadrale, ventral 

 margin parallel with dorsal surface of body, posterior cusp well 

 defined, posteroventral edge scarcely oblique, nearly vertical ; pleonal 

 epimera with rounded posteroventral corners, epimeron 3 with strong- 

 ly convex posterior margin; outer ramus of uropod 1 about three 

 fourths as long as inner, curved apically, dorsal and lateral margins 

 unarmed, bearing one mediobasal spine, inner ramus broad, apex fal- 

 cate, armed with marginal and terminal setae; rami of uropod 2 

 elongate, longer than peduncle, smooth basally, outer ramus armed 

 with one terminal seta, inner with three ; telson poorly preserved, each 

 apex with at least one spine. 



HoLOTYPE. — AHF No. 6034, female, 5.6 mm. Unique. 



Ttpe-locality.— Station 7230, 27°52'25'' N, 115°44'30" W, 2667- 

 2706 m, Dec. 31, 1960. 



Relationship. — This species has its closest affinities with Meta- 

 phoxus pectinafus (Walker, 1896) and differs from M. fultoni (Scott) 

 (see Chevreux and Fage, 1925) in its gnathopods and from M. fre- 

 quens J. L. Barnard (1960b) by its maxillipeds, among other charac- 

 ters. It resembles several species of Phoxocephahis more closely than 

 it does members of Metaphoxus but the vestigial mandibular molar 

 marks it as a species of Metaphoxus. The new species differs from 

 M. pectinatus in the stout hand of the first gnathopod, by the reduc- 

 tion in size and length of the outer ramus of uropod 3, the presence 

 of terminal setae on the rami of uropod 2, the absence of eyes and the 

 more strongly quadrate coxa 4 with its more strongly defined posterior 

 cusp. MetapTioxus shniXlimus and M. pectinatus resemble two species 

 of deep-sea Plwxocephalus., P. kergueleni (Stebbing, 1888) and P. 

 tenuipes Steplu \sen (1925) in the elongation of pereopod 5 but M. 

 simiUhnus is even more similar to P. hergueleni than is BI. pectinatus 

 because of the occurrence of a modified outer ramus of uropod 1. 

 Plioxoceplmlus tenuipes., from the north Atlantic bathyal, has equal 

 rami on uropod 1. The resemblance of Metaphoxus shnillimus to 

 P. hergueleni is remarkable, even to the similarity of antenna 1 and 

 its anterodorsal process on article 1. Except for the absence of eyes 

 it also resembles a shallow-water sympatriot Phoxocephalus homilis 

 J. L. Barnard (1960b). Metaplioxus simiUim.us differs from both 

 P. hergueleni and P. homilis by the presence of terminal setae on the 

 outer rami of uropod 2 and the absence of setae on the ventral margin 



