1914.] NATURAL SCIENCES OF PHILADELPHIA. 255 



GYMNOTID^. 

 ELECTROPHORIN^. 

 Electrophorus electricus (Linnaeus). 



One example 346 mm. 



STERNOPYGIN.E. 

 Sternopygus macrurus (Schneider). 



Five examples, 128 to 432 mm. 



Eigenmannia virescens (Valenciennes). 



Two examples, 305 and 338 mm. 



Gymnorhamphichthys hypostomus Ellis. 



Two examples, 100 and 138 mm. 



STERNARCHIN^. 



Sternarohus albifrons (Linnaeus). 



Two examples, 141 and 173 mm. These agree largely with Cope's 



example, recorded as Sternarchns albifrons from the Peruvian 



Amazon.^5 It differs, however, in having the light predorsal streak 



continuous from the head to the origin of the dorsal fin. The 



Rupununi examples show it only for the first quarter or third of this 



region. They also show the following: Head 5| to 6j; depth 5^ 



to 5|; A. 150? to 160?; scales about 72 to 90 in 1. 1. according to 



tubes and pores; 15 to 18 scales above 1. 1., opposite pectoral tip, 



counted to median line of back; 3 or 4 scales above 1. 1. to dorsal 



origin; about 116 to 120 predorsal scales; about 30 scales below 



I. 1. at greatest body depth; snout 2f to 2| in head; interorbital 



4^; maxillary If to If in snout; eye 3| to 5|; gill-rakers 2 -j- 5 or 6. 



These two examples also differ from one another in respect to color, 



the larger having a black and rather long slender caudal peduncle. 



The smaller has a very constricted caudal peduncle, marked by a 



dusky blotch, and the caudal dusky, while in the larger example 



the caudal is white. 



ASPREDINID^. 

 Bunooephalus amaurus Eigenmann. 



One example, 40 mm. long. It differs from Eigenmann's account 

 in the head width, which is 3f in total length. Barbels banded 

 basally. Maxillary barbel not quite reaching pectoral. Eigenmann 

 gives^^ as a distinction from Bunocephalus gronovii Bleeker, in his 



^ Proc. Amer. Philos. Soc, Phila., XVII, 1878, p. 628. 



IS Mem. Carnegie Mus., Y, 1912, p. 126, Pi. 2 (non 1), fig. 2. 



