PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 97 



Pleueonichthts ccenosus Girard. 



D. 72-7G. A. 40-54. C. 3-14-3. P. 10-13. Y. G. 



Body broad, comparatively thick ; nape almost continuous witb snout, 

 and much less curved than the part of the dorsal outline immediately 

 behind it. At the seventeenth dorsal ray the dorsal outline commences 

 to rise rapidly, forming a bold and regiilar sweep from thence to the end 

 of the dorsal. Abdominal outline nearly a straight line to the ventrals, 

 thence curved like the dorsal. Greatest depth of body |^, length of 

 head about f , of the total length ; longitudinal diameter of orbit nearly 

 ^ of the length of the head ; width from tip to tip of expanded dorsal 

 and anal fins nearly f of the total length. Caudal peduncle usually 

 about i as wide as the greatest depth of the body, widening- considera- 

 bly toward the caudal base. Snout extremely short and bluff, its length 

 less than } of the diameter of the orbit, and its profile cut oft' from that 

 of the nape by the jirojection of the upper orbital margin. Nostrils of 

 right side in a depression on the horizon of the upi)er margin of the lower 

 eye, those of the blind side on the dorsal ridge slightly behind the front 

 margin of the orbit; both anteiior nostrils with atlap; posterior patulous. 

 Eyes elliptical, very large, even in front, the upper directed obliquely 

 upwards, the upper bony ridge of its orbit raised above the dorsal ridge. 

 Interocular space a very narrow bony ridge, its extremities raised into 

 l)rominences, and scarcely -^" wide in a specimen 9^" long-. This ridge 

 continues forward round the anterior margin of the upper eye to its raised 

 upper margin; on the posterior margin of the up])er eye there are also 

 two almost spinous prominences. Mouth small, extremely oblique, 

 nearer vertical than horizontal ; the end of the maxillary, in consequence 

 of this obliquity, scarcely reaching- the front margin of the orbit; man- 

 dible not projecting in the closed mouth. Lips thick, fleshy, and plicate. 

 Teeth very small, acute, in a broad band in the mandible on the blind 

 side and for about two-thuxls of the length of the colored side. On the 

 intermaxillaries a much narrower band on the blind side, scarcely reach- 

 ing to the s^^nphysis; none on the colored side of these bones. Teeth 

 of the blind side of the mandible very slender, much recurved. Each 

 upper pharyngeal with a row of about eight conical, sharp, recurved 

 teeth ; lower i)haryngeals with a double row of very small teeth. All 

 the teeth buried deeply in the gum, only their points \isible. The lower 

 pharyngeal bones are very small and slender. A i)rominent short ridge 

 between the origin of the lateral line and the tubercles of the hinder 

 margin of the upper eye ; from the anterior end of this a long low prom- 

 inence runs downwards across the opercular bones, slightly inclining- 

 forwards, and ending- level with the row of pores und«}r the eye. Mar- 

 gin of the preoi)erculum luiited by the skin to the other opercular bones. 

 Gill-rakers very short, flexible, wide apart. Dorsal fin twisted over to 

 the left side at a ijoint over the centre of the eye (about ten rays from 

 its origin) and continued <lownwards in a curved line to a little below 

 the posterior extremity of the n)axillary on that side, the first rays 

 Proc. Nat. Mus. 79 7 Sept. 1©, 1 8 7f>. 



