284 THE AMERICAN CHARACIDAE. 



Scales regularly imbricate, no interpolated rows. Lateral line somewhat 

 decurved. Anal with a sheath of a single row of scales along the base of the 

 anterior rays. Scales with a few faint radial striae. 



Origin of dorsal about equidistant from snout and caudal, highest dorsal 

 ray 4 in the length. Caudal lobes about 3.5 in the length. Origin of anal 

 under last caudal ray. Ventrals vary, reaching the anal. Pectorals scarcely 

 to the ventrals. 



Highly iridescent silvery; a bright silvery lateral band, a faint humeral 

 band, no caudal spot. 



Differing from A. guianensis in the partially naked cheek, etc. 



For Marion Durbin Ellis, collaborator in monographing the minute Tetra- 

 gonopterinae. 



40. AsTYANAX RUBERRiMUS Eigcnmami.^ 

 Plate 44, fig. 1; Plate 49, figs. 2 and 3. 



Aslyanax rvherrimus Eigenmann, Indiana univ. studies, 1913, no. 18, p. 25. 

 Astya7ia.r aeneus ? Regan {non GUnther), Ann. mag. nat. hist., 1913, ser. 8, 12, p. 465. 



Habitat. — Pacific slope of Colombia and both slopes of Panama. 



'Since the account of A. rubeirimus was prepared Mr. S. F. Hildebrand has examined several 

 thousand specimens of Astyanax collected in Panama on both the east and west slope. They came from 

 the Chagres River of the Atlantic side and from both the Mamor6 Basin and Tuyra Basin of the Pacific 

 side. He has come to the conclusion that there are two species of Astyanax in the fresh-waters of 

 Panama. One of these is the widely distributed A. fasciatus (Cuvier) which is abundant in the Atrato 

 River of the Atlantic drainage of Colombia occurring in very small numbers in the head-waters of the San 

 Juan of the Pacific side of Colombia. This species is the one described by Steindachner as fischeri and 

 by Meek as grandis from the Mamortf Basin. The second species is the ruberrimus of the San Juan and 

 other Pacific streams of Colombia. All of the specimens enumerated below belong to this second species 

 but are more slender. They have the shape of A.fasciatus and the color of ruherrimus. In representing 

 them I used the figures of fischeri published by Steindachner but modified the color-markings (pi. 49, 

 fig. 2, 3). This was at a time when I supposed that but one species A. fischeri existed in the Mamore 

 and that the specimens enumerated belonged to that species. It would seem therefore that either the 

 specimens enumerated below should be listed under ruberrimus or that they represent a variety without 

 a name. The name fischeri is a synonym of fasciatus. 



The specimens erroneously identified as A . fischeri are : — 



It is possible that some of the younger ones, (20688) in which the caudal spot is continued to the 

 end of the middle caudal rays are in reality A . fasciatus. 



Mr. S. F. Hildebrand, in his volume on the fishes of Panama records this species from a great 

 variety of localities on both slopes of the Canal Zone and from the Mamor(? and Tuyra Basins of the 

 Pacific slope of Panama south of the Canal Zone. 



