594 GEOLOGICAL SURVEY OF THE TERRITORIES. 
accredit the statement. This idea has no doubt been brought about by 
the fact that sometimes a few families of prairie dogs (Cynomys), for in- 
stance, will start an independent village, which, from some cause or the 
other, they are afterwards led to desert; whereupon the owls are only 
too glad to avail themselves of the empty burrows, and the traveller is 
very likely to find one or two such peaceful colonies in the course of his 
rambles, as the writer has, where the owls are present, but all signs of 
the rodents obliterated, in some cases even the grass and flowers having 
grown again to the very entrances of the burrows. 
Speotyto, unlike the majority of the members of the great family to 
which it belongs, is not strictly nocturnal in its habits, but on the con- 
trary one may find them wide awake and active, in the villages where 
they are found, at almost any hour of the day ; indeed, as a rule they 
are quite wary, and one may often resort to all of the stratagems his 
experience has taught him before he succeeds in securing a specimen. 
In powers of flight they are weaker than most owls, a fact largely due 
no doubt to the lack of exercise of this privilege. 
As we pass to the study of the skeleton of this interesting species, we 
shall, no doubt, find several instances wherein it has been modified and 
received certain impressions due to the mode of life and habits of the 
owner, that we have so briefly called the reader’s attention to. Weadd 
here also a cut showing some of the external characters of this bird. 
In enumerating and describing the separate bones of our subject, the 
smaller ones of the ear have not been taken into consideration, as they 
more properly come to be treated in the study of the organ of hearing ; 
certain very small sesamoids may also, with propriety, be overlooked. 
The skull.—As a general rule, it is only in the young of the Class Aves 
that the many bones of the skull can be separated from one another; 
the majority of the primitive segments of ossification of the four ver- 
tebr’ that go to form this, the superior expansion of the vertebral col- 
1 My reader will no doubt remember that this monograph, accompanied by another 
of about equal size, upon the Osteology of Hremophila alpestris, appeared in the Bul- 
letin of the United States Geological and Geographical Survey of the Territories, vol. 
vi, No. 1, Washington, February 11, 1881, being followed in the same year, September 
19, in No. 2 of the same volume, by my monographs upon the Osteology of the North 
American Tetraonide and Lanius ludovicianus excubitorides. In one and all of these pa- 
pers I considered the cranium as composed of four vertebrze, as many of the old school 
comparative anatomists had done before me, and in adopting this theory I likewise 
‘adopted the nomenclature ef the elements as given by Professor Owen, in his Anatomy, 
and Physiology of Vertebrates. When I was first privileged to enter upon my ana- 
tomical studies, comparative and otherwise, this theory was the then prevailing one, 
and my mind became imbued with its fascinating precepts, its plausibility and appa- 
