SOUTH AMERICAN CHARACID FISHES — WEITZMAN 145 



palatine. For reasons discussed below, I tenatively prefer to call 

 this bone the accessory ectopterygoid. Along the lateral edge of the 

 ectopterygoid and accessory ectopterygoid is a row of large, conical 

 teeth. Medial to this row on both bones is a narrow patch of small, 

 conic teeth. In Erythrinus and Hoplerythrinus the ectopterygoid 

 extends from the quadrate to over the ventral surface of the palatine 

 (autopalatine). The ectopterygoid in both bears a band of conic 

 teeth. In Hoplerythrinus, but not in Erythrinus, small conic teeth 

 are present on the ventral surface of the mesopterygoid. In a speci- 

 men of Hoplerythrinus unitaeniatus, 115 mm. in standard length, 

 from British Guiana, CAS(IUM) 12331, the mesopterygoid teeth are 

 well developed and cover much of that bone's lower surface; however, 

 a specimen from Peru, SU 35044, which is 120 mm. in standard 

 length, has only a few scattered teeth over the mesopterygoid. 



Hoedeman (1950b) described a new genus and species in the 

 Erythrininae, Pseuderythrinus rosapinnis, from Dutch Guiana. His 

 new genus seems distinguishable from Hoplerythrinus only by the 

 number and distribution of teeth on the palatal arch. He recorded 

 a narrow band of teeth on the palatines and no teeth on the "ptery- 

 goid" for Pseuderythrinus, and he stated that Hoplerythrinus has a 

 broad patch of teeth on the palatine and that there are teeth on the 

 pterygoid. Hoedeman's pterygoid is the ectopterygoid of the present 

 account. Examination of a cleared and alizarin-stained specimen and 

 other, nonstained specimens of Hoplerythrinus does not confirm Hoede- 

 man's views concerning the placement of teeth in this genus. I find 

 that Hoplerythrinus has teeth on the ectopterygoid, no teeth on the 

 palatine, and it may have a broad patch of teeth on the mesoptery- 

 goid. The mesopterygoid teeth may be numerous or few and they 

 are usually fewer in small specimens. It seems likely that the speci- 

 men, 128 mm. in standard length, forming the basis of Hoedeman's 

 new genus, has as yet failed to develop a dense aggregation of mesop- 

 terygoid teeth, and it seems likely that this genus is a synonym of 

 Hoplerythrinus. The color and other characters of Pseuderythrinus 

 rosapinnis are very much like those of Hoplerythrinus unitaeniatus; 

 further investigations probably would indicate that, at most, P. 

 rosapinnis is a subspecies of H. unitaeniatus. The type of Pseudery- 

 thrinus rosapinnis needs reexamination. 



Hoedeman (1950b, p. 85) recorded palatine teeth present in Hoplias, 

 Hoplerythrinus, and Erythrinus and stated that there are no teeth 

 on the "pterygoid" in Erythrinus. This disagrees with what I found 

 in the specimens at hand. 



No specimens of these genera were found to have palatine teeth 

 attached to the palatine. This fact is difficult to determine and re- 

 quires considerable and careful dissection, especially in Erythrinus 



