404 BIRDS OF ILLINOIS. 



" Nyctea. Slzi'viTy liiri;i> (wine 15.00 Inohes or mort-). Four outiTiniillK with liiiior 

 U'i'liH I'limrcinulcHl. Lowit liiil-coverls n'uchlnd "nil nf tall; toes ilonscly oov- 

 erud with Ions Imlr-Uko fouthors which ulmoat completely hide the elawo: Mil 

 iienrly concealed by the loml feathers. Ear-tults rudimentary. (Otherwise 

 Hlmlliir to liuhn.) 

 Si ThII much eraduiited. nearly ua lone us the wine. 



8. Snrnia. Size nither small (wliiBiibuut 9 Inehesl. Four outer qulllt- with inner 

 webs omarclnuted. the third lonsi'st. Bill strong, yellow: Iris bricht yellow. 

 Ear-eonoh oval, simple, less than the diameter of the eye. No cur-tufts, 



h. Nostril opening back from the anterior margin of the much Inflated nasal mem- 

 brane; usually small and circular, 

 5 Tarsus little If any longer than the middle toe; first nuill shorter than tenth, 



9. Olauoidiiun, Size very small (wing less than 4.50 Inches), Tarsus about eiiual 

 to the niidclle toe, densely feathered; tail much ra6re than half the wing, 

 rounded; third ur fourth nuill longest, the outer four with Inner webs emargi- 

 iiiitcl; tiill pale colored; iris yellow, 



I". Micrathene, 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 nuill 

 longest, the oiiter four with inner webs emarglnated; bill pale colored. Iris 

 yellow. 

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

 tile si.xth. 



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 Brisb, Orn. 1, 1760, 28. Type, Strix oltin LiNS. 

 Utus Cuv. Lee. Anat. Comp. 1799, tab. 11. Same type, 



liradii/otus GouLD, P, Z. S, lSt7, 10. Type Slrix. hraehyolua FoB8T,.=5. accipilrina 

 Tall. 



Gen. Chab, Size medium. Ear-tufts well developed or rudimentary: head small; 

 eyes small. Cere much arched, its length more than the chord of thcculmen. Hill 

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

 emarglnated. Tail about half the wing, rounded. Ear-conch very large, about a.s long 

 as the height 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 grr-iitly developed. (.Isio.) 



I. A. wiUonianuB, Above flnely-vermloulnted dusky brown and light grayish, the 

 former prevailing: lower parts whitish (bulTy beneath the surface), marked with 

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



B. Ear-tufts nuliiiiintary. iUracliyolim.) 



~. A. aooipitrinue. Ground-color (above and below) ochraeeous, varying to bulTy 

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



The subgenus A sin has but one other representative, as far as 

 known, in America. This is the .1, utiiiiiim (W.vcl.) of the tropical 

 regions (including Cuba), which differs from .1. irilnonianiig in much 

 darker coloi-, perfectly naked toes, and attenuated tips to the outer 

 primaries. A. wilsoitianus has a close ally in A. otl^s of the Palae- 



