1906. 



NATURAL SCIENCES OF PHILADELPHIA. 



333 



Edges of body but little trenchant, or only upper and lower surfaces 

 of caudal peduncle and postventral region. Rami of mandible well 

 elevated inside mouth. Rakers 10 + 14 on first arch, lanceolate, 

 and longest about length of filaments which are f of orbit. Scales non- 

 striate. Color in alcohol brow^nish, back darker and lower surface 

 paler, washed everywhere with more or less silvery. A dull leaden 

 streak, a little high, from below dorsal to caudal and then continued 

 out on its middle rays as dusky. Fins otherwise all dull brownish. 

 Iris dull brassy. Length If inches. 



Two examples, wTongly identified by Cope with Astijanax diaphanus. 



Aphyocharax pusillus Giinther. Fig. 22. 



Cope, Proc. Acad. Nat. Sci. Phila., 1871 (1872), p. 260. Amb\aacu River, 

 Eastern Equador. John Hauxwell.— — ^Cope, Proc. Amer. Pliilos. Soc. 

 Phila., XVII, 1877-78 (May 17, 1878), p. 689. Permian Amazon. 

 Prof. J. Orton. 



Interorbital space 2|- in head. Snout convex. Rami of mandible 

 but little elevated inside of mouth. Tongue a little elongate, fleshy 

 and free in front. Interorbital space broad and a little convex. Gill- 

 openings extending forward till nearly opposite front margin of pupil. 



^^ 



Fig. 22. — Aphyocliarax pusillus Giinther. 



Rakers 7 + 8, short, pointed, and much less than filaments. Isthnms 

 narrow and with median groove. Each scale with 2 or 3 striae. Color 

 in alcohol brown, sides paler, and body more or less brassy. Fins 

 brownish, median caudal rays dusky. Iris brownish. Length 2y^6 

 inches. Peruvian Amazon. Orton. Coll. of 1873. 



