SUB-GENERA OF CHAR ACINUS. 9.55 



its mouthy which is smaller ; in its teeth ; and in not 

 having the belly carinated. These are followed by 

 Chalceus, which differs materially from all the fore- 

 going, by having the hinder part of the body lengthened, 

 and the pectoral fin so long as to reach to the vent : 

 the unusual development of this fin, as seen in C. an- 

 gulatus (Spix, pi. 34.), is very remarkable, and de- 

 serves much attention, because it will materially help to 

 determine the station of this type in a natural arrange- 

 ment. We retain the original generic name of Chara- 

 cbius to those which have been subsequently called 

 Curimata by Cuvier. These fishes, whose teeth vary 

 in almost every species, are nevertheless readily dis- 

 tinguished from all the other salmons, by their elon- 

 gated form, by the smallness of the mouth, and, 

 more especially, by having the anal fin as short as any 

 of the European salmons : their external similarity, in 

 fact, to Coi'egonus, indicates a clear relation of analogy, 

 if not of affinity. Following these w r e place Piabu- 

 cus Cuv., which has the general shape, mouth, &c. of 

 Characinus, but differing in the anal fin being very 

 long. Allied to all these small groups, is that of Gas- 

 teropelicus. — a singular little fish, having the shape of 

 Serrasalmo, but with the belly remarkably protruding ; 

 while the head is so raised upward, that the mouth 

 becomes completely vertical : the anal fin, as in the major- 

 ity of these groups, is very long and narrow ; and the 

 belly sharp, without being serrated. Finally, we come 

 to the genus Cynodon of Spix, whose aspect is altogether 

 different from any of the preceding fishes : the head 

 is large ; and the wide mouth, which opens downward, 

 is armed, as in Laurida, with long slender teeth of 

 different sizes : the body is lengthened, and the anal 

 fin is uncommonly long. The two very remarkable 

 species figured by Spix*, are included by Cuvier in 

 his genus Hydrocyon ; but this group contains such a 

 heterogeneous assemblage of fishes, with little or no 

 affinity to each other, that it would almost seem to have 



* C vulpinus, Spix, pi. 26. ; gibbus, pi. 27. 



