NATURAL SCIENCES OF PHILADELPHIA. 



275 



Total length . 

 Length to orbit 



" " opercular slit 



" " ventral fin 



" " anal fin 



" " caudal fin 



" of dorsal spine 



" " pectoral spine 



" " postcoracoid 

 Width of muzzle . 



" at humeral knobs 



" "1st lateral shield 

 Expanse of both pectoral spines 



Ambyiacu River, Equador. John Haiixwe 

 The preorbital comb is like that of Doras 

 from the same region. 



M. 



0.035 

 .0015 

 .007 

 .015 

 .0189 

 .028 

 .0075 

 .0123 

 .0082 

 .005 

 .013 

 .003 

 .031 



1. 



pectinifrons^ Cope, 



CALLICHTHYS ASPER, Q. Gaim. 



Giinther, v. 225. 



CALLICHTHYS MELAMPTERUS, Cope, sp. nov. 



The liead depressed, muzzle broadly rounded. Body strongly 

 compressed ; the dorsal line rising steeply and continuously with 

 the profile, to the dorsal fin. Caudal region much compressed ; 

 tail openly emarginate. Inferior lip little reverted, bearing no 

 barbels ; tip of the muzzle projecting but little beyond the mouth. 

 Inferior barbel extending to near the end of the ventral fin, supe- 

 rior to near the end of the pectoral. Lateral shields 25-24, from 

 supraclavicle. Azygous plates 5. Radii D. 8, A. 1, 6, V. 7, P. 

 I. 8. Dorsal spine like other rays, pectoral toothed within, and 

 with short tooth-like bristles without. Spine of adipose reaching 

 to basis of caudal. 



Orbit 3.5 times in length of head, twice in interorbital width. 

 Depth of head more than two-thirds length. Length of head one- 

 third length without caudal, equal depth. Length over all, three 

 inches. 



Color dark plumbeous ; the preorbital region, and caudal and 

 inferior fins, black. 



This species is much more compressed than the C. asper. Be- 

 sides other points, there is one more pectoral ray and a different 

 1872.] 



