130 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



KEY TO THE GENERA 



a. Teeth in the jaws all pointed, not serrate. 



6. Anterior nostril only in a tube, the posterior one general surrounded by a 



slightly raised membrane Gyranothorax (p . 1 30) 



bb. Both pairs of nostrils provided with tubes Muraena (p. 131) 



aa. Teeth in the jaws compressed, serrate, sharklike, in a single series. 



Priodonophis (p. 133) 



Genus GYMNOTHORAX Bloch, 1795 



Body more or less compressed; anterior nostril only in a tube, the 

 posterior one generally surrounded by a slightly raised membrane, 

 situated over or somewhat behind anterior margin of orbit; teeth 

 pointed, not serrulate, often in two series in jaws, usually in a single 

 series on shaft of vomer, the anterior teeth in botli jaws and on vomer 

 enlarged; gill opening small, lateral, nearly horizontal; dorsal and anal 

 confluent around the tail, origin of dorsal in advance of gill opening; 

 pectorals wanting. 



A single species, as here understood, comes within the scope of this 

 work. 



GYMNOTHOBAX WIENERI Saurage 



Morena; Morena Colorada 



Figure 29 



Gymnothorax wieneri Satjvage, 1883, p. 161, "Chile au Peru" (original descrip- 

 tion). — Evermann and Radcliffe, 1917, p. 26, pi. 3, fig. 3, Lobos de Afuera 

 and Callao, Peru (description).— Nichols and Murphy, 1922, p. 505, Lobos 

 de Tierra Island and Pacasmayo, Peru (3 specimens listed). — Fowler, 1941a, 

 p. 366 (references) . 



Bodj" fairly compressed, thickness at vent about half depth at same 

 place, the tail strongly compressed, terminating rather broadly, length 

 anterior to vent 2.0, 1.85 in total length; head compressed, its length 

 anterior to gill opening 8.0, 6.6 in total length, 4.3, 3.7 in length 

 anterior to vent; depth about 7.5, 5.2 in length anterior to vent, 1,75, 

 1.5 in head; snout robust, rectangular in cross section, being deeper 

 than wide, 5.2, 5.0 in head; eye small, lateral 14.7, 17 in head, 2.8, 3.4 

 in snout; mouth large, horizontal, terminal, the gape extending far 

 beyond eye, 2.25, 2.2 in head; teeth in the jaws in two series, those of 

 the outer series very small, and missing posteriorly, those of the inner 

 series large anteriorly, becoming progressively smaller posteriorly; 

 vomer anteriorly with a pair of large teeth, followed by two larger 

 single ones and a series of very short blunt teeth on the shaft; palatines 

 each with three large teeth (teeth of a smaller specimen as in the larger 

 one described, except that the vomer has only two large single teeth 

 anteriorly) ; anterior nostril with a short tube, situated well above lip, 

 near tip of snout, the posterior one surrounded by a rather narrow 

 raised membrane, situated over anterior margin of orbit; gill opening 



