VERTEBRATA: AVES. 



631 



usually form an incomplete or complete " disc " or circle round 

 each eye (fig. 349, B), and a circle of plumes is likewise placed 



Fig- 349 A Foot of Tawny Owl (Ulula. stridula) ; B, Head of White Owl 

 (Strixflammea). 



round each eiternal meatus auditorius. Besides this auricular 

 circle of featlers, the external meatus of the ear is likewise 

 protected by i fold of skin. The legs are short and strong, 

 and are furnisied with four toes, all armed with strong crooked 

 talons. The mter toe can be turned backwards, so that the 

 foot has someresemblance to that of the Scansores. The tarso- 

 metatarsus is densely feathered (fig. 349, A), and the plumes 

 sometimes exend to the extremities of the toes. The oeso- 

 phagus is not dlated into a crop ; and the indigestible portions 

 of the food are rejected by regurgitation from the stomach 

 in the form of small pellets. The Owls hunt their prey in 

 the twilight or on moonlight nights, occasionally by day, and 

 they live mostly upon the lesser Mammalia and small birds, 

 though .hey vill also eat insects or frogs. 



Thf section of the Diurnal Raptores includes the four groups 



of tte Falcordd(z, the Vtilturidcz, the Cathartidce, and the Gypo- 



gerCiidcz. T^ie eyes in this section are much smaller than in 



thf preceding, and are placed laterally; and the plumage is not 



<at. As regards their power of flight, they show a decided 



Advance upon the Nocturnal Birds of Prey. The wings are 



long and pointed ; the sternal keel and pectoral muscles are 



greatly developed ; and many of the members of this section 



exhibit a more rapid power of locomotion than is seen in any 



other division of the animal kingdom. The bill is long and 



strong, with a large " cere " at the base of the upper mandible, 



in which the nostrils are pierced. The tarso-metatarsus and 



toes are usually covered by scales, and are rarely feathered. 



