Cockerell and Moore — Nature of Teeth in Ctenoid Scales. 93 



too far along the line of modification in regard to the circuli to 

 be able to produce them. The more primitive Characinidse, 

 however, have been able to develop marginal teeth more than 

 once, independently. 



According to our view, a scale can not have marginal teeth, 

 and transverse circuli running below them. Thus Sebastodes and 

 Pomotis have scales with similar basal radii, and in many- 

 respects alike, but Sebastodes has vertical apical circuli, and is 

 ctenoid, while Pomotis has them transverse and is absolutely 

 cycloid . 



