STRiaiD^ — THE OWLS. 7 



In their distribution, the Owls, as a family, are cosmopolitan, and most of 

 the genera are found on both hemispheres. All the northern genera {Nyctea, 

 Surnia, NydaU, and Scotiaptex), and the majority of their species, are cir- 

 cumpolar. The genus Glaucidium is most largely developed -vvithin the 

 tropics, and has numerous species in both hemispheres. Otus hrachyotus 

 and Strix Jlammea are the only two species which are found all over the 

 world, — the former, however, being apparently absent in Australia. Gymno- 

 gtaux, Speotyto, Mlcrathene, and Lophostrix are about the only well-character- 

 ized genera peculiar to America. Athene, Kctupa, and Phodilus are peculiar 

 to the Old World. The approximate number of known species (see Gray's 

 Hand List of Birds, I, 1869) is about two hundred, of which two, as stated, 

 are cosmopolitan ; six others (Surnia ulula, Nyctea scandiaca, Glaucidium 

 passerinum, Syrnium cinereum, Otus vidgaris, and Nyetale tengmahni) are 

 found in both halves of the Northern Hemisphere ; of the remainder there 

 are about an equal numl)er peculiar to America and the Old World. 



As regards the distribution of the Owls in tlie Nearctic Eealm, a promi- 

 nent featvire is the number of the species (eighteen, not including races) 

 belonging to it, of which six {Micrathene ivhitneyi, Nyetale acadica, Syrnium 

 nebulosum, S. occidentale, Scopis asio, and S. flammeola) are found nowhere else. 

 Speotyto cunicjilaria and Bubo virginianus are peculiarly American species 

 found both north and south of the equator, but in the two regions represented 

 by different geographical races. Glaucidiuiyi ferrugineum and G. infuseaturn 

 (var. gnoma) are tropical species whicli overreach the bounds of the Neo- 

 tropical Realm, — the former extending into the United States, the latter 

 reaching to, and probably also within, our borders. Of tlie eighteen North 

 American species, about nine, or one half {Strix Jlammea var. piratincola, 

 Otus hrachyotus, 0. vulgaris var. wUsonianus, Syrnium cinereum, Nyetale 

 acadica, Bubo virginianus, and Scops asio, with certainty, and Nyctea 

 scandiaca var. arctica, and Surnia ulula var. hudsonia, in all probability), 

 are found entirely across the continent. Nyetale teiignialmi, var. richardsoni, 

 and Syrnium nehidosum, appear to be peculiar to the eastern portion, — the 

 former to the northern regions, the latter to the southern. Athene cunicularia 

 var. hypugaca, Micrathene ivhitneyi, Glaucidium passerinum var. calif ornicum, 

 Syrnium occidentale, and Scops flammeola, are exclusively western, all belong- 

 ing to the southern portion of the Middle Province and Eocky Mountain 

 region, and the adjacent parts of Mexico, excepting the more generally dis- 

 tributed Speotyto cunicularia, var. hypugwa, before mentioned. Anomalies in 

 regard to the distribution of some of tlie species common to both continents, 

 are the restriction of the American representative of Glaucidium passerinu7n 

 to the western regions,-' and of Strix Jlammea to the very southern and 



^ Tliis case of the restriction of the American representative of a European or Western Palse- 

 arctic species to the western lialf of the continent has parallel instances among other birds. 

 The American form of Falcolanarius (var. po/ijntjrus), of Corvus corax (var. carnivorus), Pica 

 caudata (var. hudsonka and var. nuttalli) and of ^■Egialitis cantianus (var. nivosus), are either 



