50 
U. 8. P. R. R. EXP. AND SURVEYS— ZOOLOGY GENERAL REPORT. 
This variety appears to be restricted to western North America, and is represented by the 
majority of the specimens in the present collection. So far as can be determined from prepared 
skins, the average of these specimens would be rather smaller than in the preceding, but there 
are some quite as large as we have ever seen of that variety. This variety can readily be 
distinguished from the preceding by the facial disk being ashy, instead of fulvous. 
Variety. — Bubo virginianus arcticus, Cassin. 
Bubo arcticus, Swainson, Faun. Bor. Am. Birds, p. 86. (1831.) 
Bubo sub-arcticus, Hoy, Proc. Acad. Phila., VI. p. 211. (1852.) 
Bubo septenhionalis, Brehm? 
Strix scandiaca, Linnaeus? 
Figure. — Faun. Bor. Am. Birds, pi. 30. 
Light colored, frequently nearly white. General plumage of a predominating pale yellowish white, or cream color, of 
various shades, from nearly pure white to nearly the color of the two preceding varieties. Under parts generally lighter than 
the upper, and always throughout the plumage marked and barred with brown, frequently pale and indistinct, but in the same 
general manner as in the preceding. Tarsi and toes generally very light, frequently nearly pure white. Size generally about 
the same as that of variety atlanticus, and the plumage with more or less of the same reddish fulvous at the bases of the feathers. 
Feathers of the face pure white, or pale cream color, sometimes tinged with fulvous and cinereous. 
This variety appears to inhabit the northern and western countries of North America, and 
probably occasionally all other parts of that portion of the continent. Mr, Swainson's figure, 
above cited, represents an unusually white specimen, though we have seen such, and from that 
shade to but slightly lighter than the common variety. So far as we regard ourselves compe- 
tent to judge, this variety is better entitled to be regarded as a distinct species than any other. 
Variety. — Bubo virginianus magellanicus, Cassin. 
Strix magellanicus, Gm. Syst. Nat. I, p. 286. (1788.) 
Strix nacurutu, Vieill. Nouv. Diet. VII, I, p. 44. (1817.) 
Bubo ludovicianus, Daudin, Traite d'Orn. II, p. 210. 
Figure.— BufFon PI Enl. 385. 
Very variable in color, but generally darker than either of the preceding ; plumage at bSSe fulvous. Feathers of the fsECS 
usually pale cinereous, more or less tinged with fulvous ; size about the same as the preceding, or rather larger. 
This variety inhabits, apparently, South America, and perhaps Mexico, and the extreme 
south of the United States. Of this we have seen specimens darker than of either of the? 
preceding varieties, and more resembling Mr. Audubon's figures than are usually tnzt with in 
northern localities. 
This fine species is either subject to considerable variety in the color of its plumage, or Ihere' 
are several species, some of which have been named by naturalists, as cited above, in our sy&o-* 
nymes. But with no less than thirty specimens now before us, from nearly all parts of North 
America, we confess ourselves quite unable to detect characters sufficient to distinguish more 
than one species. We have, therefore, to regard them all as Bubo virginianus, and to attribute 
the differences in their colors to variety only, either local or caused by accidental circumstances. 
With but a single well characterized specimen each of perhaps four varieties, the inducement would 
be strong to regard them as distinct species, so different are their colors ; but with an extended 
series, like the present, all the characters exist in such various degrees of modification, and are 
so blended that it is to us quite impossible. We have designated the varieties of this species 
in Birds of California and Texas, I, p. 1*78, and have no reason to change our views from the 
examination of the present collection, except that these varieties are evidently not to be regarded 
