BIRDS 



317 



MEASUREMENTS OF ADULT SPECIMENS OF GeOSpiza fuliginOSd 



acutirostris. 



62e. GEOSPIZA FULIGINOSA DIFFICILIS (Sharpe). 



Geospiza difficilis SHARPE, Cat. Birds Brit. Mus., xn, p. 12, 1888. RIDGWAY, 

 Proc. U. S. Nat. Mus., xix, p. 532, 1896 ; Bull. U. S. Nat. Mus., 50, Pt. 

 i, p. 507, 1901. ROTHSCHILD AND HARTERT, Novit. Zool., vi, p. 163, 

 1899. 



Range. Abingdon Island. 



This form is very close- to G.f. acutirostris of Tower, from which 

 it differs in the slightly larger bill. Some of our specimens, however, 

 are quite indistinguishable from specimens of G.f. acutirostris and 

 we have, hence, united this form with the fuliginosa group. This 

 gives two subspecies of G. fuliginosa to Abingdon, but G. f. 

 difficilis is quite distinct from G.f. minor. This latter species, also, 

 as before stated, inhabits only the lower parts of the island, ranging 

 from sea level up to about eight hundred feet. G. f. difficilis, on the 

 other hand, appears to be restricted to the higher parts of the island, 

 where it is common. It was the only form seen above fifteen hundred 

 feet, and it was here most abundant, while below five hundred feet 

 it was not met with at all. 



This is one of the few forms that occur on Abingdon but not on 

 Bindloe. Perhaps the lesser height of the latter island, which does not 

 reach an altitude greater than eight hundred feet, accounts for the 

 restriction of this species to Abingdon. 



We must now make a break in the series which leads on uninterrupt- 

 edly from the form last described through G. debilirostris and G. 

 septentrionalisto the forms comprising the next and highest subgenus, 

 Cactornis. We do this in order to go back again to G. fuliginosa 

 parvula and insert another series which begins with G. fortis and 



