256 MEMOIRS OF THE CARNEGIE MUSEUM 



margin then describing a quarter circle and continuing in a di- 

 rection nearly parallel with that of the premaxillary. 



Creatochanes. 

 N N. Anterior maxillary-premaxillary border forming a simple curve. 

 0. Teeth of the sides of the lower jaw abruptly smaller. 



P. Premaxillary teeth in three series; anal of not more than 



fourteen rays Creagrutus. 



PP. Premaxillary teeth in two series. 



Q. Four teeth in the inner series of the upper jaw; second 

 suborbital covering entire cheek. Bryconamericus. 

 QQ. Five teeth in the inner series of the lower jaw. 

 R. Scales cycloid. 



S. Predorsal line scaled Astyanax. 



SS. Predorsal line naked Poecilurichthys. 



RR. Scales ctenoid Ctenobrycon. 



00. Teeth of the sides of the lower jaw graduated Deuterodon. 



A" A". Preventral area with two series of large overlapping scales Phenacogaster. 



(FF. Gill-rakers short, lanceolate Scissor.) 28 



EE. Lower jaw with two series of teeth, the inner series consisting of a pair of conical teeth within 

 the outer series, and beginning at a greater or less distance from these a series of minute 

 teeth on the sides. (Bryconinm.) 

 T. Scales alike above and below. 



U. No fontanels Holobrycon. 



U U. Two large fontanels Brycon. 



TT. Scales much larger above the lateral line Chalceus. 



CCA predorsal spine, scale-like; caudal scaled. (Stethaprioninm.) Fowlerina. 



nn. Preventral area compressed, trenchant, more or less expanded; pectorals large. 

 V. Body elongate, lateral line continued to the tail. (Chateau ita.) 



Chalcinus. 

 V V. Body short; the lateral line deflected to before the anal; sternum much 

 expanded; skull with longitudinal crests. (GasU-nipclccimc.) 

 IF. No adipose fin; maxillary with a single, large, hooked tooth. 



Carnegiella. 

 WW. Adipose fin present; maxillary with large, hooked teeth; premaxillary 



teeth in a single series Gasteropelecus. 



mm. Belly and preventral area trenchant and serrate. 



X. All teeth in the jaws in a single series. (SerrasalmincB.) 



Y. A series of teeth on each side of the palate Serrasalmo. 



YY. Palate without teeth. 



Z. Teeth with simple cutting edge Pygocentrus. 



ZZ. Teeth serrate Pygopristes. 



XX. Premaxillary teeth in two series. (MylvruB.) 

 a. Mandible with a single series of teeth. 



p. Abdomen serrate before and behind the ventrals; premaxillary teeth 

 conical; lower jaw much projecting Catoprion. 



28 The place from which Scissor came is not known. 



