OSTARIOPHYSI 



577 



number 3 to 5 only. The fins never bear pungent spines, and 

 the ventrals have 6 to 13 rays. Barbels are absent. In most 

 of the herbivorous forms the brain-case is produced forward to 

 the nasal capsule, whilst in most of the carnivorous forms they 





■so- . '-> -r ••' ij' 





D 



Fig. 349. — Open mouths of Characinidae. (After Mtiller and Troschel.) A, Macroihm 

 tmh ira ; B, Piahucina argmtina ; C, Brycon falcatus ; D, ChcUceus angulatus ; 

 E, Serrasalmo rhombeus ; F, Distichodus niloticus. 



are separated by an interorbital septum ; but there are exceptions 

 to this correlation, and as otherwise closely related genera may 

 differ in this respect, I have not been able to make use of the 

 character in defining sub-families. 



VOL. VII 2 p 



