DESCRIPTION OF A NEW SPECIES OF RIBBON FISH, 

 TRACHYPTERUS REX-SALMONORUM, FROM 

 SAN FRANCISCO. 



BY DAVID S. JORDAN AND CHARLES H, GILBERT. 



Trachypterus rex-salmonorum, species nova. Plate ix. 



:=Trachypierus altivelis Jordan and Gilbert, Proc. U. S. Nat. Mus., 

 1881, 5-2; and Synopsis Fishes of North America, 1882, 618; not 

 of Kner. 



Head 8|- in length; cross depth at nape 8. Dorsal 

 rays, V — 170 ; caudal ra3^s 8; ventral rays 6; pectoral 

 II. Total length of specimen, with caudal, 17 inches. 



Body long and slender, closely compressed and ribbon- 

 shaped, as usual in the genus. Head short, deeper than 

 long, the anterior protile steep and nearly straight to the 

 base of the nuchal crest: dorsal fin beginning on the 

 top of the nuchal crest, which is directly over the second 

 third of the diameter of the eye : height of crest slightly 

 more than diameter of eye, the latter greater than length 

 of snout and }4, length of head. Mouth oblique; maxil- 

 lary rugose and ver}^ broad, its width ^ its length; 

 length of lower jaw greater than length of snout, 2^ 

 in head, its angle under the front of the orbit. Oper- 

 cular bones rugose, entirely covering the gills. Pre- 

 maxillary covered with minute and feeble teeth, in ad- 

 dition to which in this specimen are three canines, two on 

 one side and one on the other, directed very obliquely 

 backwards. On the side having two canines, one is 

 placed directly behind the other. Lower jaw with three 

 strong canines on one side and two strong and one weak 

 canine on the other, all directed obliquely backwards and 

 inwards. 



Dorsal fins slightlv connected at base; the filamentous 

 rays of the first dorsal not quite twice the length of the 



2d Ser., Vol. IV. May 0, 1894. 



