NO. 3538 CHARACID FISHES — WEITZMAN 21 



well-preserved specimens) with few irregularly scattered melano- 

 phores. No evidence of tertiary stripe. Single broad pale brown 

 stripe (probably silvery in well-preserved specimens) above primary 

 horizontal stripe extending from eye to caudal fin base. Two areas of 

 large scattered melanophores occurring on pale stripe, forming oblique 

 bands; anterior band covering 4 scales anterior to a point below 

 anterior origin of dorsal fin, posterior band covering another 4 scales 

 and center of this area located at a point dorsal to vent. Just dorsal 

 to pale stripe a narrow secondary stripe arising a short distance above 

 termination of upper opercular opening and extending posteriorly 

 through center of second scale row to below dorsal fin, here becoming 

 wider, denser, and rising to top of second scale row, there merging 

 with dark pigment of dorsum behmd dorsal fin and above pale stripe 

 on caudal peduncle. Dorsum anterior to dorsal fin pale brown, lighter 

 than secondary stripe. Top of head and snout with scattered large 

 and small melanophores forming an area darker than dorsum just 

 anterior to dorsal fin. All fins colorless except for a few scattered 

 melanophores and dark pigment on lower caudal lobe. Pelvic fins 

 appear artificially stained gra}^. 



Color in life. — Life colors are taken from the original English 

 description. Primary horizontal stripe "brilliant" black, extending 

 onto caudal fin rays and onto lower caudal lobe. Typical wedge-shape 

 distribution of pigment on lower caudal fin lobe apparently not 

 present but precise distribution of black pigment not stated. Dorsal 

 and ventral region dusky, back darker. Faint "reddish flush" on 

 base of caudal and anal fins. Pelvic tipped with "ice blue," especially 

 in males. Sides above and below primary horizontal stripe white 

 except for narrow "golden-red streak" above primary stripe. (Hoede- 

 man stated that this streak is diffuse at times except on snout. From 

 this I woidd assume that there is probably a golden or red metallic 

 spot at the anterior narial openings as in so many other nannostomi- 

 nans.) Secondary horizontal stripe present but tertiary stripe 

 absent. 



Remarks. — Concerning his new species, A^. bifasciatus, Hoedeman 

 (1954a) stated: "Phylogenetically the new species seems close to the 

 stem of the tribe [i.e., his tribe Nannostomidil, near the presumed 

 Pre-Nannostomid, taking an intermediate position between Nanno- 

 stomus beckfordi and Nannobrycon eques." Hoedeman's opinion was 

 apparently based on the following observation: "The oblique swim- 

 ming position of Nannobrycon though less pronounced is sometimes 

 observed in the present species [bifasciatus] also, especially while 

 nipping planktonic food from the plants." He also mentioned that 

 the black pigment of the caudal fin extends on the lower caudal 

 fin lobe somewhat as in Poecilobrycon eques and remarked that the 



