gg PROCEEDINGS OF THE NATIONAL MUSEUM vol.99 



and below pectoral fin base and more or less enclosing it, except pos- 

 teriorly; margin of eye not free, eye small, a little over two times in 

 the interorbital space; interorbital space convex, about 3 times in dis- 

 tance from snout tip to occiput; fontanel present from between 

 eyes to occiput. 



Color. — Body light brownish in alcohol with 17 narrow dark-brown 

 bars across sides to end of anal fin, sometimes an incomplete or broken 

 bar between most of or all the nearly complete bars; pectoral fins 

 and anal fin with numerous dark brown pigment specks; tail beyond 

 anal fin with about 3 more brown bars more or less obscure or absent. 



Genus RHAMPHICHTHYS Muller and Troschel 



Rhamphichthys Mullek and Troschel, Horae ichthyologicae, pt. 2, p. 15, 1849. 

 (Genotype, Gymnotus rostratus Linnaeus.) 



RHAMPmCHTHYS ROSTRATUS (Linnaeus) 



Gymnotus rostratus Linnaeus, Systema naturae, ed. 12, vol. 1, p. 428, 1766. 

 Rhamphichthys schomburgki Steindachner, Sitzb. Akad. Wiss. Wien, vol. 58, 



p. 10, 1868 (Rio Negro). 

 Rhamphichthys pantherinus Peters, Monatsb. Akad. Wiss. Berlin, 1877, p. 473 



(San Fernando de Apure, Venezuela). — Sachs, Aus den Llanos, 1879, p. 279 



(Apure). 

 Rhamphichthys marmoratus Eigenmann and Eigenmann, Proc. U. S. Nat. Mus., 



vol. 14, p. 62, 1891 (Orinoco). — Eigenmann and Ward, Proc. Washington 



Acad. Sci., vol. 7, p. 168, fig. 12, 1905 (Orinoco and Guianas south to Rio 



de la Plata). 

 Rhamphichthys rostratus marmoratus Ihering, Rev. Mus. Paulista, vol. 7, p. 280, 



1907 (Venezuela). 



Genus APTERONOTUS Lacepede 



Apteronotus Lacepede, Histoire naturelle des poissons, vol. 2, p. 208, 1800. 

 (Genotype, Apteronotus passau La.eepMe = Gymnotus albifrons Linnaeus.) 



Sternarchus Bloch and Schneider, Systema ichthyologicae, p. 497, 1801. (Geno- 

 type, Gymnotus albifrons Linnaeus.) 



KEY TO THE SPECIES REPORTED FROM VENEZUELA 



la. Dorsal profile of head rounded or convex, the snout blunt; interorbital space 

 3.25 to 3.5 in the head; rear margin of eye at middle of head length; snout 

 about two-thirds length of pectoral fin and about 3 times in greatest depth; 

 depth of head at occiput 1}^ in its length; a white band from tip of snout 

 along middorsal line to top of head; two white bands encircle body, the 

 first at rear of anal fin and the second smaller at origin of caudal fin; anal 



rays 155 to 170 Apteronotus albifrons (Linnaeus) 



16. Dorsal profile of head concave or straight in young, snout elongate, not blunt; 

 interorbital space 6 to 9 times in the head and 2 to 2.5 in the snout. 

 2a. Anal fin hyaline or pale; snout elongate, equal to pectoral fin and about 2 

 times in greatest depth; depth of head at occiput 1.8 to 2 in its length; 

 rear of eye about at middle of length of head; a white band from snout 

 tip along middorsal line to and including dorsal filament; tip of chin 

 white; posterior end of caudal peduncle encircled with white; anal rays 

 142 to 158 Apteronotus leptorhjoiclius (Eigenmann) 



