STRIGID^E. 115 



bristles, which are part of the facial disk ; the upper mandible is 

 usually entire, and the lower one sometimes notched ; the nostrils 

 are generally situated in the anterior part of the cere. The feet 

 are well formed for grasping, the outer toe being versatile, and 

 the claws are generally strong and sharp, and the hind toe 

 very short. 



The skull of the nocturnal Raptores is short, but high vertically, 

 and the furrows are very distinct. The bony plates of the eye are 

 very strong and thick, extending over a large surface of the eye ; 

 but Owls do not possess the superciliary ridge which forms the 

 projecting eyebrow in most of the Falconidce. The external ears 

 are furnished with a large crescentic membranous flap or valve. 

 The sternum is smaller than in Falconidce, short, somewhat 

 convex, and the keel less developed ; and the posterior margin has 

 two fissures or emarginations on each side in most, or one shallow 

 cleft in a few. The furcula is thin beneath, and sometimes even 

 membranous. The mouth is wide, the oesophagus large and without 

 any dilatation, the stomach more muscular than in the Falconidce ; 

 the intestines are long, and there are two enormous casca, usually 

 dilated at their extremity. Their lungs are largely developed, as 

 are the air cells, and the bones are highly pneumatic, especially 

 the bones of the head, which' contain large cavities communicating 

 with the ears. 



Owls feed either by twilight or during the night, and live on 

 small mammalia, especially mice, rats, and shrews, also on birds, 

 which they sometimes surprize when sleeping, various reptiles, 

 fishes, and insects. The indigestible portion of their food, as 

 hair, bones, scales, &c., are formed into pellets in the stomach, 

 and disgorged. 



Tliey are mostly arboreal, some of them roosting in holes in 

 rocks or buildings. Their eggs, which they lay in holes in trees 

 or buildings, are always white, and of a rounded form. The 

 female is a little larger than the male, but does not otherwise 

 differ. Most Owls have loud voices, and their names, in many 

 languages, are derived from their calls, howling, hooting, or 

 screeching. Many species arc looked on with awe and supersti- 

 tion by the uneducated in all countries, and their unearthly 



