SOUTH AMERICAN FISHES 



31 



9. Insignificant and unimportant characters like tlie scaling- 

 of the caudal may be a better indication of relationship than con- 

 spicuous organs whose modification may be of selective value. 



10. Individuals of a long and firmly established genus some- 

 times revert to the characters of the genus from which it has arisen. 

 Apparently members of the same brood may belong to different 

 long recognized genera. 



