47 
Interior of British North America. 
Institution at Woolwich; so that there can be no doubt of the 
identity of my eggs. Now Dr. Brewer figures this Buzzard’s 
egg (N. A. 0. pi. 3. fig. 26) as being “ of a yellowish white/’ 
“ marked with large blotches of a light, but very distinct, 
purplish grey,” and measuring “2-^g- by 1-tt. inches,”—whereas 
my eggs present very much more the appearance of the eggs of 
the Common Buzzard, and exhibit similar variations. One of 
them is white, with large distinct blotches and smaller specks 
of two shades of brown; another is more obscurely blotched 
with paler brown, and at the same time freckled nearly all over. 
They measure— 
Spec. a. 2*6 by 2*0 inches, 
Spec. b. 2*5 by 1*95 inches, 
being thus considerably larger than is represented by Dr. 
Brewer, besides being quite differently coloured. Mr. Bernard 
Ross seems doubtful about this bird on the Mackenzie. 
11. Circus hudsonius. (See f Ibis,’ vol. iii. p. 319.) 
Also common on the Mackenzie (Bernard Ross). 
12. Aquila canadensis. (See * Ibis/ vol. iii. p. 319.) 
Also Mackenzie River, to the Arctic Coast (Bernard Ross). 
13. Haliaetus leucocephalus. (See ‘ Ibis/ vol. iii. p. 319.) 
Also Mackenzie River, to the Arctic Coast (Bernard Ross). 
14. Pandion carolinensis. (See f Ibis/ vol. iii. p. 320.) 
Also Mackenzie River, to the Arctic Coast (Bernard Ross). 
15. Bubo virginianus. 16. Bubo ardicus. 
In my first paper ( f Ibis/ vol. iii. p. 320) the light-coloured 
variety of the Great Horned Owl was placed as a distinct species 
from B. virginianus. I am, however, very doubtful of the correct¬ 
ness of this view, and consequently would prefer keeping it under 
the original name; otherwise we shall have to allow at least three 
species, all differing from the type. Professor Baird, of the 
Smithsonian Institution, whose complete ornithology of North 
America has been published as a volume of the ‘ Pacific Railroad 
Reports’ by order of the United States Government, has had 
perhaps greater facilities for examining into this subject than 
any one else; he thus sums up (p. 50 ):—“ We have, therefore, 
