474 



PROCEEDINGS OF THE ACADEMY OF 



[Oct., 



on surface. Teeth large in mandible, those anteriorly forming trans- 

 verse series of 4 largest and other 5 on each side of mandible graduated 

 down posteriorly. Anterior mandibular teeth with cutting edges, and 

 each one at symphysis with a large cusp. In upper jaw 5 teeth in 

 each external series approximated with 4 transverse annectant ones, 

 which latter together with last 3 externals, are bicuspid. Tongue 

 thick and not free. Lips a little fleshy. Interorbital space broadly 



Fig. 55. — Colossoma nigripinnis (Cope). 



convex. Gill-opening forward to front edge of eye. Rakers 39 + 39, 

 slender, about ^ of orbit. Filaments equal orbit. Tubes in lateral 

 line simple. Color in alcohol olivaceous-brown, greenish most 

 likely due to preservative, and lower regions but little paler. 

 Trunk with many blackish or dusky blotches as large as or a 

 little^ larger than pupil, those below smallest. Membrane of fins 

 more or less dusky-brown, dorsal paler, and also bases of caudal, 

 pectoral and ventral pale. Lips dusky or brownish. Iris yellowish. 

 Length 5|- inches (caudal damaged). 



