132 



MEMOIRS OF THE CARNEGIE MUSEUM. 



Ground-color uniform yellowish; top of head and mid-dorsal region, also 

 parts of the caudal portion of the body, more or less sparsely covered with minute 

 black dots; fins hyaline, anal rays very weakly colored with a clear light brown. 



Distribution: Lower, Middle, and Upper Amazons. 



V. Steatogenes Boulenger. 



Steatogenes Boulenger, Trans. Zool. Soc. London, XIV, 1898. 



Type, Rhamphichthys elegans Steindachner. 



With fontanels; no caudal; snout short; distinguished from all the other Gymno- 

 tids by the presence of a small cylindrical filament of tissue in a groove on each side 

 of the mental region; otherwise as in Hypopomus. Size rather small, not exceeding 

 250 mm. Fore part of body heavy, caudal portion tapering rapidly into the caudal 

 filament; head chubby; gape short; teeth wanting; mouth rather small; eyes small, 

 covered by a transparent membrane. Scales cycloid, lateral line complete and 

 straight. 



Fig. 6. Steatogenes elegans (Steindachner). 



8. Steatogenes elegans (Steindachner). 



Rhamphichthys (Br achy rhamphichthys) elegans Steindachner, Fisch-f. Cauca and 



Guayaquil, 37, 1880 (Barra do Rio Negro). 

 Brachyrhamphichthys elegans Eigenmann and Eigenmann, Proc. U. S. Nat. Mus., 



XIV, 1891, 62. 

 Steatogenys elegans Boulenger, Trans. Zool. Soc, XIV, 428, 1898 (Rio Jurua); 



Eigenmann and Ward, Proc. Wash. Acad. Sci., Vol. VII, 1905, 171 (Barra 



do Rio Negro); Eigenmann and Bean, Proc. U. S. Nat. Mus., XXXI, 666, 



1907 (Lower Amazon); von Ihering, Os Peixes do Brazil, Part 1 A, 1907; 



Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, 449 (Barra 



do Rio Negro and Guiana). 



