OWLS. 393 



with the sides nearly parallel, the ridge or keel very prominent, 

 and well advanced, the posterior margin with four notches. 

 The coracoid bones are long, considerably flattened, moderately 

 spreading ; the furcula very slender, of the form of the letter 

 V, never so wide as in the Hawks ; the scapulae very long, nar- 

 row, and nearly straight. The bones of the wing are of mode- 

 rate length. The pelvis is rather large ; the femur short, the 

 patella distinct, the tibia rather long, the fibula, which is slen- 

 der, partially united to it ; the tarsus generally short, never 

 long ; the phalanges of the toes two, three, four, and five. 



Owls in general are of nocturnal habits. Their enormous 

 eyes, of which the iris is most delicately sensitive, enable them 

 to perceive an object in the dim twilight, or even amidst the 

 gloom of night ; and the extreme development of the external 

 aperture of the ear, with its marginal fringes, is calculated to 

 collect and concentrate the faintest undulations of sound. It 

 is generally believed that the eyes of Owls shine in the dark, 

 but I have failed to discover any such reflection of light from 

 them, although I have examined those of two species with 

 reference to this subject. They prey on small quadrupeds, 

 birds, and insects, especially nocturnal lepidoptera and large 

 beetles. Some species also prey occasionally on fishes. They 

 kill their prey by pouncing upon it, and thrusting their talons 

 into it. If large, they carry it off' in their claws, but if small, 

 transfer it to the bill. Small birds and mice are usually swal- 

 lowed entire ; large animals are plucked and torn into morsels ; 

 and the indigestible parts being subsequently collected into 

 pellets in the stomach, are disgorged. Many owls and hawks 

 feed on precisely the same animals, — the Barn Owl and the 

 Hen Harrier for example. AMiy the Hawks should have a 

 very large oesophageal dilatation, and minute or obsolete coeca, 

 while the Owls have the oesophagus of uniform width, and the 

 cocca large, is by no means obvious. Fanciful explanations are 

 easily made, and as easily refuted. The only hawk known to 

 me which has no crop is Nauclerus furcatus, described at 

 p. 277 ; yet there is nothing peculiarly strigine in its form or 

 manners. 



In accordance with the nocturnal habits of the Owls, a pecu- 



