BIRDS OP NORTH AND MIDDLE AMERICA. 621 



NoBtril a krge oval or roundish opening at anterior end of cere, the latter not 

 inflated, except (sometimes) laterally; pteryla of pileum arranged in longi- 

 tudinal rows." 

 0. Tail much leas than two-thirds as long as wing, truncate or slightly rounded; 

 tarsus much more than one-ninth as long as wing; length of cere on top 

 more than half as long as chord of cuhnen. 

 d. Longer under tail-coverts, falling far short of tip of tail; bill mostly exposed, 

 claws wholly so; color not white, 

 e. Smaller (wing not more than 200 mm., UBUa,lly much less); cere inflated 

 laterally. 

 /. Without ear-tufte; tarsus with much more than lower half naked (some- 

 times wholly so) Gymnasio (p. 676). 



ff. With ear-tufts; tarsus with not more than lower half naked, usually 

 feathered to base of toes (even the toes sometimes feathered or bristled) 



Otus (p. 681). 

 ee. Larger (wing 230-475 mm.); cere not inflated laterally. 

 /. With conspicuous ear-tufts. 



g. Fifth, sixth, and seventh, 5 primaries longest, the tenth (apparent 

 outermost) not longer than secondaries; ear-tufta composed of rela- 

 tively longer and narrower feathers; toes entirely naked; bill and 

 feet relatively much weaker; size smaller (wing about 300 mm.). 



Lophostrix (p. 732). 



gg. Seventh, eighth, and ninth « primaries longest, the tenth much 



longer than secondaries; ear- tufts composed of relatively shorter 



and broader feathers; toes feathered (except terminal phalanges); 



bill and feet relatively much stouter; size larger (wing 350-475 mm.) . 



Bubo (p. 736). 

 ff. Without ear-tufts. 



g. Toes feathered (except terminal phalanges); bill and feet relatively 



much stouter, the former less compressed Fulsatrix (p. 754). 



gg. Toes completely naked; bill and feet relatively much weaker, the 



former more compressed Ciccaba (p. 759). 



dd. Longer under tail-coverts reaching nearly if riojt quite to tip of tail; bill and 

 claws mostly hidden by long bristle or hair-like feathers; color white 

 (more or less barred or transversely spotted with slate color). (Size 



of Bubo) Nyotea (p. 767). 



cc. Tail much more than two-thirds as long as wing, graduated; tarsus less than 

 one-ninth as long as wing (shorter than middle toe, with claw); length of 



cere on cop less than half as long as chord of culmen Sumia (p. 772). 



. Nostril a small circular opening near middle of the inflated (semibulbous) cere; 



pteryla of pileum xmiformly and thickly feathered. 

 c. Seventh and eighth, or sixth, seventh, and eighth, <* primaries longest, the 

 tenth (apparent outermost) shorter than second « (sometimes shorter than 

 first);/ tarsus slightly if at all loiter than middle toe with claw; outer toe 

 only slightly shorter than inner toe; smaller (wing less than 120 mm.). 



This last character assumed as to Lophosirix, Bubo, Pulsatric, Ciccaba, Nyctea, 



Sumia. 



?ourth, fifth, and sixth from outside. 



Second, third, and fourth from outside. 



Third and fourth, or third, fourth, and fifth from outside. 



S'inth from outside. 



Tenth from outside. 



