1906.] NATURAL SCIENCES OF PHILADELPHIA. 319 



4f ; interorbital space 3; pectoral H; ventral 1|; least depth of caudal 

 peduncle 2f. Eye midway in depth of head. Gill-opening extend- 

 ing forward till about opposite middle of orbit. Rakers 22? + 38?, 

 compressed, cuneated triangularly, and inner edge of each ciliate. 

 Gill-filaments about equal to i of orbital diameter. Scales above 

 pectoral anteriorly, both above and below lateral line, and on breast, 

 enlarged. Scales on base of caudal also a little large. Scales on post- 

 dorsal region of back formed into more or less convergent series and 

 larger than those just below. Lower lobe of caudal much longer than 

 upper, just the reverse of that indicated by Kner. Length 9 inches 

 (caudal damaged). One example from Robert Perkins, taken between 

 the mouth of the Rio Negro and the Peruvian Amazon. 



Also two smaller examples from the Peruvian Amazon. Prof. J. 

 Orton. Coll. 1873 and 1877. Prof. E. D. Cope. These both show 

 about 120 scales in lateral line to base of caudal, and 7 or 8 more on 

 latter. Middle of lower lobe of caudal dusky longitudinally, and 

 deepest basally. The Perkins example shows this as faint. 



CITHARININ.5^. 

 Citharinus citharus (Geoffroy St. Hilaire). 



Citharinus geoffroii Giinther, Proc. Zool. Soc. London, 1896 (February 4), 

 p. 223. Lake Rudolf. Dr. A. D. Smith. 



Head 2f ; depth 2^; D. iv, 14, i; A. v, 24, i; scales 83 in lateral line 

 to base of caudal, and 5 more on latter; 21 scales in a vertical series 

 between origin of dorsal and lateral line; 17 scales between origin of 

 anal and lateral line in a vertical series; snout 4^ in head; eye 3^; 

 width of mouth 3; interorbital space 3; base of dorsal 1|; base of anal 

 1^; least depth of caudal peduncle 3§; pectoral If; ventral H. Back 

 rather elevated, profile forming an angle at origin of dorsal. Lower 

 profile of body more or less evenly convex. Head becoming com- 

 pressed below. Snout short and broad. Eye about circular. Inter- 

 orbital space broad and a trifle convex. Gill-rakers not evident. 

 Color in alcohol, back brownish from a little above lateral line, and 

 lower surface and side silvery- white. Fins pale brownish. Iris pale 

 straw-color. Length 2| inches. Two examples, the other a little 

 smaller. They both differ from the original figure of Geoffroy St. 

 Hilaire in the straight upper anterior profile. 



PITHECOCHARACIN.C subfam. nom. nov. 



(Anostomince Auct.) 



PITHECOCHARAX gen. nov. 



Type Salmo anostomus Linnseus. 



Snout narrow and conic, and mouth superior. 



