42 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



on the upper edge of the bone. The vomerine teeth are reduced to a pair of very small 

 teeth in the middle of the bone. Palatine teeth none, or reduced to a single tooth-like pro- 

 jection. 



Branchiostegals long, narrow, slender. Gills as in Bathytroctes macrokpis. Gill rakers 

 long, lanceolate, closely set, 20+7 on the outer branchial arch. 



Vent nearer to the gill opening than to the root of the caudal. Origin of the dorsal 

 fin somewhat in advance of the vent; it is much longer than high, the length of the ante- 

 rior rays increasing to the sixth or seventh ray. Origin of the anal fin below the anterior 

 half of the dorsal, which it resembles in shape. Caudal fin deeply emarginate. Pectoral 

 inserted a short way above the lower profile, rather short and broad, about as long as the 

 eye. Ventrals broad, extending to the vent, their root being rather nearer to the base of 

 the caudal than to the extremity of the snout. 



Scales simple, cycloid, in about 1-' longitudinal series above and below the lateral line, 

 between the dorsal and ventral fins. Lateral line straight, running from the upper end 

 of the gill opening along the middle ot the tail, with rather small mucous apertures. 



Color, uniform black. 



Eadial formula: D. 20; A. 17; V. 9; P. 16; L. lat. ca. 100. 



A specimen 6J inches long was taken by the Challenger off Pernambuco, station CXX; 

 depth, 675 fathoms. 



A very small, pointed, osseous projection in front oft he clavicular symphysis reminds us 

 of a similar peculiarity iu the following genus Platytroctes. 



BATHYTROCTES MICROLEPIS, GCnther. 



Bathytroctes microti pis, (Ji ntheh, Ann. and Mag. Nat. Hist.. 187n. ii. 249; Challenger Report, xxn, 1887, 226, 

 pi. I.vn, tig. A. — ALCOCK, Ann. and Mag. Nat. Hist.. 1889, 451. 



The maxillary extends to below the posterior third of the orbit. Height of the body 

 r»i in total length (without caudal), the head 3f. Bones of head thin (as in Bathytroctes 

 macrolejyis). Head rather compressed, moderately deep, its depth at the occiput being two- 

 thirds of its length; its upper surface is concave, the width of the interorbital space being 

 one-half of the longitudinal diameter of the eye. Eye very large, rather longer than deep, 

 one-third of the length of the head, and considerably longer than snout. Infraorbital ring 

 rather narrow, the broad maxillary separated from the orbit by a very narrow strip of bone. 

 Snout somewhat wedge-shaped, with upper profile declivous, with jaws equal in front and 

 with maxillary extending to posterior third of the orbit. Dentition feeble; all the teeth 

 equally minute and uniserial; intermaxillary and maxillary toothed throughout; vomerine 

 series transverse and straight, slightly interrupted in middle; palatini series nearly as long 

 as vomerine. Branchiostegals slender, rod-shaped. Gills four, that of fourth arch being 

 short and reduced to a horizontal series of lamina', which is only one-third of the horizon- 

 tal series of the outer branchial arch. Gill laminae very short, especially on the convex 

 portion of the arches; gill rakers long, lanceolate, closely set, 24+11 on the outer branchial 

 arch. 



Vent considerably nearer to root of caudal fin than to gill opening, whilst origin of 

 the dorsal fin is somewhat nearer to latter. Dorsal fin longer than high, its anterior rays 

 increasing in length to fifth or sixth ray. Origin of anal behind vertical from middle of 

 dorsal fin. Caudal tin deeply emarginate. Pectoral inserted a short way above lower 

 profile; it has a moderately broad base, is three-fifths of the length of the head, and does 

 not extend to ventral. Ventrals close together, scarcely extending to vent, their root being 

 midway between root of caudal and anterior margin of orbit. 



Scales deciduous, cycloid, with numerous fine concentric and radiating stria-; there 

 were probably 9 scales in a transverse series between the lateral line and the origin of the 

 dorsal fin and between the lateral line and the ventral fin. Lateral line straight, running 

 from the upper end of the gill opening along the middle of the tail, with rather narrow 

 mucous apertures. Color, uniform black. (Giinther.) 



