144 BULLETIN 50, UNITED STATES NATIONAL MUSEUM 



nostrils; outer side of thighs with feathers moderately elongated, 

 phimelike. Adults plain gray becoming darker, sometimes black, on 

 pileum, dark brown, or cinnamon-rufous above, the tail banded with 

 black; color of underparts variable, usually barred with white and 

 cinnamon-rufous or rufous-brown, rarely white broken only by dusky 

 shaft streaks or narrow faint stripes on breast and sides and with 

 thighs cinnamon-rufous, sometimes uniform rufous or slate-gray, 

 with cinnamon-rufous on thighs and under tail coverts white. Young 

 dusky to grayish brown above, the feathers margined with rusty or 

 bufTy, beneath white on buff, usually with longitudinal (rarely with 

 transverse) markings of brown, sometimes immaculate. 



Range. — Nearly cosmopolitan, but absent from Lesser Antilles and 

 Galdpagos Archipelago. (Seven species in North and Middle 

 America.) 



Figure 13. — Accipiter (Astur) geniilis. 

 KEY TO THE SPECIES AND SUBSPECIES OF ACCIPITER " 



a. Inner toe (without claw) equal to two proximal joints of middle toe; wing 

 over 280 mm. 

 h. Whole plumage white, with faint bars, streaks, or mottlings of pale gray 

 (northeast Siberia east of Yana River; Kamchatka). 



A. gentilis albidus (extralimital)" 



" Included in this key are all the forms known to occur in the regions covered 

 by this work and all those extralimital forms found in closely adjacent countries, 

 that possibly may be found as accidental visitors. 



'« Aster palumbarius albidus Menzbier, Orn. Geogr. Eur. Russia, 1882, 438 

 (Amurland and Kamtschatka) .— ^si«r candidissimus Dybowski, Bull. Soc. Zool. 



