272 bulletin: museum of comparative zoology. 



Considerable study of the South American species of this genus leads to the 

 belief that variation in the amount and distribution of color has resulted in the 

 description of a number of species which will not prove valid when large numbers 

 of specimens can be brought together for study, but a careful examination of the 

 types in various European museums should precede any work of this kind if 

 trustworthy results are to be expected. 



