GAMMARIDEAN AMPHIPODA 107 



Bathyniedon covilhani J. L. Barnard 



P.athymcdon covUhani J. L. Barnard, 1961, p. 85, fig. 53; 1966a, p. 75, fig. 27. 



Material.— Station 7229 (2). 



Distribution. — Gulf of Panama to middle Baja California, 549- 

 1720 m. 



Bathymedon flebilis, new species 



Figure 49 



Diagnosis. — Rostrum obsolescent ; eyes absent ; lateral cephalic lobe 

 rather ventrally located, small, subquadrate; epistome rounded ante- 

 riorly; [antennal articles damaged or broken;] coxa 4 subquadrate, 

 much broader than coxa 3, scarcely excavate posteriorly and not lo- 

 bate; gnathopods of equal stoutness, gnathopod 2 much longer than 

 1, fifth article much longer than sixth, that of second gnathopod 1.3 

 times as long as article 6, gnathopod 1 with small posterior lobe on 

 article 5, lobe symmetrically rounded and not demarcated from article, 

 lobe scarcely evident on long fifth article of gnathopod 2, article 4 lack- 

 ing posterodistal tooth, article 5 strongly and asymmetrically ex- 

 panded distally, thus palms much longer than posterior margins of 

 sixth articles ; article 7 of pereopods 1 and 2 slightly longer than article 

 6; anteroproximal surface of article 2 of pereopod 5 with non- 

 setose ridge, article 2 broadly ovate, nearly subcircular, posterior edge 

 rounded and sloping to obsolescent postero ventral corner ; telson trun- 

 cated, pi'obably bearing two distal setae but only one detectable, other 

 minor setae asymmetrically situated. 



Remarks. — Mouthparts similar to those of B. longlmanus (Boeck) 

 (see Sars, 1895, pi. 117) but right lacinia mobilis bifid, each molar 

 bearing one long liemi-plumose seta, grinding cusps poorly developed 

 on one edge of molar; outer lobes of lower lip more rounded than in 

 B. longimanus; inner plates of maxilliped with oblique apical edges. 



Antennae, appendages and uropods are badly broken; the ventral 

 edges of pleonal epimera 2 and 3 apparently are sparsely setose. 



HoLOTYPE. — AHF No. 6114, female, 5.4 mm. 



Type-locality.— Station 7231, 27°24'00" N, 115°12'15'' W, 2398- 

 2475 m, Jan. 1, 1961. 



Material.— Stations 7229 (1 whole and 1 badly damaged) , 7231 (1) . 



Relationship. — This species is similar to Bathymedon gorneri Gur- 

 janova (1951) by virtue of the poorly developed rostrum, truncate tel- 

 son and the general shape of the gnathopods ; however, gnathopod 2 

 of B. -flebilis has a much longer and more slender fifth article with 

 poorly developed posterior lobe, than does B. gorneri. The missing 

 first antennae prevent a further comparison with B. gorneri. Bathy- 

 medon ivanovi Bulycheva (1952) also is shnilar to B. flebilis but 



242-332—67-^—8 



