SOUTH AMERICAN CHARACID FISHES — WEITZMAN 135 



Regan (1912) lumped the genera Chalceus, Pyrrhidina, Copeina, 

 and Pogonocharax into a "natural group," stating that they differed 

 from the rest of the Characidae by a very large mesethmoid (= ethmoid 

 of this work), oblong or elongate body form, rounded abdomen, 

 fiattish upper surface of the head, large scales, and short dorsal 

 and anal fins. These are superficial characters and do not indicate 

 true relationships. The osteology of Chalceus appears to be in many 

 respects like that of Brycon and there is reason to beheve that 

 Chalceus may have been derived from Brycon or a very close ancestor. 

 In any event, its osteology is typically that of the Characinae as 

 defined by Weitzman (1962). The case of Pogonocharax rehi, a fish 

 described by Regan and presumed by him to be from South America, 

 was reviewed by Myers (1956b, p. 13); the fish is not a characid but 

 an Asiatic cyprinid of the genus Esomus. 



Gregory and Conrad (1938, pp. 324, 343-344) recognized the sub- 

 family Erythrininae for the inclusion of the Erythrininae and Lebi- 

 asininae of Regan (1911). Superficially, Regan's two subfamilies do 

 look much alike but they are separated by the characters listed below 

 in the classification. Gregory and Conrad (1938, p. 343) have noted 

 the resemblance of Hepsetus (= Sarcodaces) to Hoplias; indeed, 

 Hepsetus possesses a supraopercular like Hoplias. The cranial bones 

 do have a superficial and perhaps even a phylogenetically significant 

 resemblance to those of Hoplias. Basically, however, the osteology 

 of Hepsetus is more like that of the Characinae, especially with regard 

 to the pectoral girdle. In addition, Hepsetus has four branchiostegal 

 rays, a clear anastomosis between the dermopterotic and supraorbital 

 laterosensory canals, no accessory ectopterygoid, and the usual 

 characid number of eight orbital bones. Certain features of the skull, 

 however, such as the frontal-sphenotic articulation and the presence 

 of a supraopercular are characters in common with the Erythrininae but 

 not the Characininae and suggest that'" the relationships of Hepsetus 

 should be investigated further. In addition, the possible relationships 

 of Ctenolucius and Boulengerella with Hepsetus should not be ne- 

 glected. Preliminary examination indicates that the relationships of 

 Acestrorhynchus and Acestrorhamphus are probably with Charax, 

 Roeboides, and other closely related genera in the Characinae, not with 

 Boulengerella and Ctenolucius as assumed by Gregory and Conrad 

 (1938, pp. 323-324, 338-344). These authors followed Regan (1911) 

 in placing Nannostomwi and Poecilobrycon with members of the 

 Hemiodontinae. 



Hoedeman (1954b, p. 55 ; 1956a, p. 12) presented a classification of the 

 major characid groups. Most of his work appears to be speculation. 

 The only morphological data of any value was a superficial comparison 

 of scales from several characids. In his 1956 classification, Hoedeman 



