BIRDS 



335 



dens rothschildi. The gradation in size and shape of the bill from 

 G. septentrionalis into G. scandens through G. s. scandens is com- 

 plete. Hence we begin G. scandens with this subspecies. 



MEASUREMENTS OF Geospiza septentrionalis . 



Subgenus Cactornis Gould. 



Cactornis GOULD, Proc. Zool. Soc. Lond., p. 6, 1837. (Type, Cactornis 



scandens Gould.) 

 Geospiza Gould (in part). 



Adult males same in color as adult males of Geospiza proper. 

 Sexes dissimilar. Adult females and young blackish, either in 

 plumage corresponding with Stage IV of young males of Geospiza 

 and Camarhynchus or in Stage V. Bill various, either elongate and 

 slender or thick and conical. 



This subgenus was formed by Gould for slender billed Geospizce 

 such as G. scandens. However, a distinction between Geospiza and 

 Cactornis based on the bill does not hold, but the type of Gould's 

 Cactornis can be retained as the type of a distinct group based on 

 color as given in the last paragraph. The adult females are con- 

 tinuously dusky over the upper and anterior parts, and the abdomen is 

 heavily streaked with dark brown. Young birds in the first plumage 

 resemble the adult males except that they have the rufous wing bands 



