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 arclicus, Swainson, Faun. Bor. Am. Birds, p. 86. (183L) 

 Bubo sub-arcticus. Hot, Proc. Acad. Phila., VI. p. 211. (1852.) 

 Bubo septentrionalis, 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. Hwainson'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 aay 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 (udoiucionus, Dacdin, 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 base fulvous. Feathers of the face 

 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 met with in 

 northern localities. 



This fine species is either subject to considerable variety in the color of its plumage, or there 

 are several species, some of which have been named by naturalists, as cited above, in our syno- 

 nymes. But with no less than thirty specimens now before us, from nearly all parts of North 

 America, we confess ourselves (juite 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, tlic 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. 178, 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 



