NO. 3538 CHARACID FISHES — WEITZMAN 53 



come from these respective areas. However, the som"ce of the speci- 

 mens was never reliable enough for serious consideration. 



Insufficient specimens of digrammus in good condition were at hand 

 to consider geographical variation in color pattern or other characters. 



The presence or absence of an ocellus in unifasciatas seemed geo- 

 graphically correlated, along with a few other characters. Undoubt- 

 edly ocellatus and unifasciatus -will be recognized as subspecies when 

 sufficient study material becomes available. 



Poecilobrycon eq^ues seems remarkably constant over its large range 

 from Peru to British Guiana. Both color pattern and morphology of 

 preserved specimens seem quite stable, and I have not noticed any 

 differences in Uve specimens said to be imported from Peru and 

 British Guiana. 



Summary 



The characid subtribe Nannostomina (defined by Weitzman, 1964) 

 contains two genera, Nannostomus and Poecilobrycon. Poecilobrycon 

 is divided into two subgenera, Poecilobrycon and Nannobrycon. Nan- 

 nostomus consists of six known species, Poecilobrycon of three, with two 

 of these in the subgenus Nannobrycon. The species are as follows: 



Nannostomus espei (Meinken) 



Paruma River, British Guiana. 

 Nannostomus beckfordi Giinther 



British Guiana, south through Fx-ench Guiana, and Surinam, and in the 



Amazon Basin as far west as the Rio Negro. 

 Nannostomus bifasciatus Hoedeman 



Surinam River, Surinam. 

 Nannostomus digrammus Fowler 



Rupununi district of British Guiana and west into Brazil as far as the 



Rio Negro. 

 Nannostomus trifasciatus Steindachner 



British Guiana, westward and south into the Amazon Basin as far as the 



P6bas district of Peru. 

 Nannostomus marginatus Eigenmann 



British Guiana, southward into the Amazon Basin and as far west as the 



Caquetd. Province of Colombia. 

 Poecilobrycon harrisoni Eigenmann 



Demerara River, British Guiana. 

 Poecilobrycon unifasciatus (Steindachner) 



British Guiana, Rio Negro in Brazil north to Rio Orinoco in Venezuela. 

 Poecilobrycon eques (Steindachner) 



British Guiana south into Amazon Basin and west to Pebas region of Peru, 



Rio Negro north to Caicara in Venezuela. 



