404 BIRDS OF ILLINOIS. 



7. Nyctea. Size very large (wing 15.00 inches or more). Four outer quUls with inner 

 webs emarginated. Lower tail-coverts reaching end of tail; toes densely cov- 

 ered with long hair- like feathers which almost completely hide the claws ; bill 

 nearly concealed by the loral feathers. Ear-tufts rudimentary. (Otherwise 

 similar to Bubo.) 



§§ Tail much graduated, nearly as long as the wing. 



8. Surnia, Size rather small (wing about 9 inches). Four outer guills with inner 

 webs emarginated, the third longest. Bill strong, yellow; iris bright yellow. 

 Ear-conch oval, simple, less than the diameter of the eye. No ear-tufts. 



6. Nostril opening back from the anterior margin of the much inflated nasal mem- 

 brane; usually small and circular. 

 § Tarsus little if any longer than the middle toe; first quill shorter than tenth. 



9. Glaucidium. Size very small (wing less than 4.50 inches). Tarsus about equal 

 to the middle toe, densely feathered; tail much more than half the wing, 

 rounded; third or fourth (luill longest, the outer four with inner webs emargi- 

 nated; bill pale colored; iris yellow. 



10. Miorathene. Size very small (wing less than 4. .50 inches). Tarsus a little longer 

 than middle toe, scantily haired; tail less than half the wing, even; fourth quill 

 longest, the outer four with inner webs emarginated; bill pale colored, iris 

 yellow. 



§§ Tarsus more than twice as long as the middle toe; first quill longer than 

 the sixth. 



11. Speotyto, Size moderately small (wing about 7.00 inches). Tarsus closely feath- 

 ered in front nearly or quite to the toes, naked behind; tail less than half the 

 wing, slightly rounded; bill light colored; ins yellow. 



Genus ASIO Brisson. 



Asio Beiss. Orn. i, 1760, 28. Type, Strix otus Linn. 

 Otus Cnv. Lee. Anat. Comp. 1799, tab. ii. Same type. 



Brachyotus Gould, P. Z. S. 1837, 10. Type Strix hracliyotus Foest.,=S. accipitrina 

 Pall. 



Gen. Chak. Size medium. Ear-tufts well developed or rudimentary; head small; 

 eyes small. Cere much arched, its length more than the chord of the culmen. Bill 

 weak, compressed. Only the first, or first and second, outer primary with inner web 

 emarginated. Tail about half the wing, rounded. Ear-conch very large, about as long 

 as the heiglit of the skull, with an anterior operculum, which extends its full length, and 

 bordered posteriorly by a raised membrance, the two ears asymmetrical. 



The two North American species belong to distinct subgenera, as 

 follows : 



A. Ear-tufts greatly developed. {Asio.) 



1. A. wilsonianus. Above finely-vermiculated dusky brown and light grayish, the 

 former prevailing; lower parts whitish (buffy beneath the surface), marked with 

 transverse dusky bars, which are much broader than the mesial streaks. 



B. Ear-tufts rudimentary. {Brachyotus.) 



2. A. aecipitrinuB. Ground-color (above and below) ochraceous, varying to buffy 

 whitish, striped, but not barred, with dark brown. 



The subgenus Asio has but one other representative, as far as 

 known, in America. This is the A. stygius (Wagl.) of the tropical 

 regions (including Cuba), which differs from A. wilsonianus in much 

 darker color, perfectly naked toes, and attenuated tips to the outer 

 primaries. A. wilsonianus has a close ally in A. otus of the Palse- 



