g NORTH AMERICAN BIRDS. 



Five quills emarginated ; toes scantly feathered, the 

 terminal scutellse exposed ; iris black. Size medium . Syrnium. 



4. Nyctale. Two outer quills with inner Avebs emar- 

 ginated. Top of cere less than half the culmen, level. With- 

 out ear-tufts. Bill yellow or blackish ; iris yellow. Size 

 small. 



ft Anterior edge of the ear-conch without an operculum. The two 

 ears symmetrical. Tail slightly rounded, only about half as long 

 as the wing. 



5. Scops. Two to five quills with inner webs emarginated; 

 second to fifth longest. Bill weak, light-colored. Ear-conch 

 elliptical, about one-third the height of the head, with a 

 slightly elevated fringed anterior margin. Size small ; ear- 

 tufts usually well developed, sometimes rudimentary. 



C. Bubo. Two to four outer quills with inner webs emar- 

 ginated ; third to fourth longest. Bill robust, black. Ear- 

 conch elliptical, simple, from one third to one half the height 

 of the skull. Size large. Ear-tufts well developed or rudi- 

 mentary. 



Ear-tufts well developed. Two to three outer quills 

 with inner webs emarginated ; lower tail-coverts not 

 reaching end of the tail. Toes covered with short feathers, 

 the claws exposed, and bill not concealed by the loral 

 feathers . . . . . . . . ■ . . Bubo. 



Ear-tufts rudimentary. Four outer quills Avith their 



inner Avebs emarginated ; lower tail-coverts reaching end 



of the tail. Toes covered Avith long feathers, Avhich hide 



the claAvs, and Ijill nearly concealed by the loral feathers . Nyctea. 



ttt Similar to the last, but the tail graduated, nearl}^ equal to the 



wing. 



7. Surnia. Four outer quills Avitli inner Avebs emarginated. 

 Third quill longest. Bill strong, yellow ; ear-conch simple, 

 oval, less than the diameter of the eye. Size medium ; no 

 ear-tufts. 



II. Nostril, a small circular opening into the surrounding inflated membrane 

 of the cere. Ear-conch small, simple, oval, or nearly round, without an 

 operculum. 



First quill sliorter than the tenth. 



8. Glaucidium. Third to fourth quills longest ; four emargi- 

 nated on inner webs. Tarsus about equal to the middle toe, 

 densely feathered. Tail much more than half the Aving, 

 rounded. Bill and iris yellow. Size very small. 



9. Micrathene. Fourth quill longest; four emarginated on 

 inner Avebs. Tarsus a little longer than middle toe, scantily 

 haired. Tail less than half the wing, even. Bill light (green- 

 ish ?) ; iris yelloAV. Size very small. 



First quill longer than sixth. 



10. Speotyto. Second to fourth quills longest ; three emar- 

 ginated on inner Avebs. Tarsas more than tAvice as long as 

 middle toe, closely feathered in front to the toes, naked 

 behind. Tail less than half the wing, slightly rounded. Bill 

 yellowish ; iris yellow. Size small. 



