NORTH AMERICAN BIRDS. 199 



already mentioned, the cavities will often contain weed-stems, corn- 

 stalks, corn-silk and feathers from the breast of the mother-bird, and 

 again the eggs will be found laid upon the bare ground or decayed wood 

 of the cavity in the presence of a few bones and skulls of animals. 



This Owl deposits two or three white, globular eggs.* Five sets of 

 two eggs each are in my cabinet from Florida, Indiana, Iowa and Ohio ; 

 the ten specimens measure, 2.18x1.72, 2.20x1.78, 2.24x1.80, 2.26 x 

 1.88, 2.26x1.79, 2.29x1.82, 2.31 X 1.88, 2.30x1.89, 2.28X 1.74, 2.32x1.80. 



A large series in Mr. Norris' collection show great variation in 

 size. 



375a. Bubo virginlanus subarcticus (Hoy.). [405 a, part.] 



Westerii Horned Oxirl. 



Hab. Western United States, from the Great Plains westward (except the northwestern coast) ; east 

 casually to Illinois, Wisconsin and western portion of Canada, north to Manitoba, south to Mexican table 

 lands. 



A lighter colored form inhabiting Western United States. Its nest- 

 ing, eggs and other characteristics are the same as those of B. virgin- 

 ianus. Four eggs in my collection from Riverside, Cal., taken in 

 March, 1884, measure, 2.16x1.78, 2.20x1.74, 2.25x1.76, 2.16x1.78. 



Mr. Norris has three sets of two eggs each ; one from Berkeley, Cal., 

 taken April 10, 1880, sizes, 2.05x1.17, 2.02x1.75; another from Los 

 Angeles county, Cal., collected March 10, 1887, show the following 

 measurements : 2.07 x 1.75, 2.13 x 1.71. The third set were also taken 

 in Los Angeles county, California, on March 3, 1887, and measure 

 2.10XI.73, 2.14x1.71. 



375<5. Bubo virginlanus arcticus (Swains.) [405^.]; 



Arctic Horned 0\irl. 



Hab. Chiefly the interior of Arctic America (Fur Countries), south in winter to the Northern Rocky 

 Mountains and Great Plains; Dakota, Montana and Wyoming. 



This bird's general plumage is whitish through the fading of the 

 ground color and restriction of the dark markings; beneath pure 

 white, with dark markings. Prof. Ridgway gives the average size of the 

 eggs as 2.19 x 1. 91. 



375^. Bubo virginlanus saturatus. Ridgw. [405^.] 



Dusky Horned Owl. 



Hab. Northwest coast, from Oregon north to Alaska; Labrador. 



An extremely dark colored race, with the face usually sooty-brown- 

 ish or grayish-white. Mr. Norris has a set of tv/o eggs of this bird taken 

 near Fort Spokane, Washington Territory, on March 14, 1886. They 

 measure 2.25x1. 85, 2.23x1.90. 



^' In exceptional cases four eggs have been taken from a single nest, but I am not aware of an authentic 

 set of five eggs or the extreme number of six of the Eastern Horned Owl as has been reported of B. v. sub- 

 arcticus in Colorado. I have in several instances received sets of four eggs of B. virginianus, as stated in the 

 last edition of this work. 



