308 



OWLS. 



HALIAETUS ALBICILLA. 



Cray Sea Eagle. 



DESCRIPTION. 



Sp. Ch. Form and general color similar to those of the White headcil Engle, hut the head is never 

 white, althongh adults have the tail wholly white, and the si/>e is somewhat larger on the average. Occurs 

 in Europe and in Greenland. Eggs similar to those of the Northern White-heads. 



Notes on the Nesting Habits of the White-heahed Eaule. This species, according to Mr. Wm. 

 Peterson, who has collected large Tiumhers of their eggs in Florida, hegins to lay in that state as early as the 

 second week in November but fresh eggs can te found as late as the second week in January. 



ORDER IX. STRTGL OWLS. 



sternum, usuallij with four marginal indentations. Keel, verij low. Manubrium, want- 

 ing. Head, quite large. 



The eyes are usually largo, directed forward, and, in n great number of the species, 

 constructed for seeing in the twilight or even at night. The bill is strong and curved but 

 is partly concealed in bristly feathers. There is a more or less perfect disk of radiating 

 feathers surrounding the face. The cavity of the ear is large. The tarsus is usually sliurt 

 and is nearly always feathered to the toes. The wings are long and well formed. The 

 plumage is soft and lax, each feather, even of the wings, being tipped with downy liia- 

 mcnts whicli insures noiseless flight, enabling the birds to take their prey with great cer- 

 tainty. The sternum is quite strong, usually with four marginal indentations, the two 

 inner, shallower than the outer. The keel is low, not exceeding one half the width of the 

 straight sternum in height. The coracoids are short, strong, and of medium length, and 

 are often set on at a wide angle but the fiircula is weak, not arched, and is provided with 

 a terminal expansion. This sternal structure indicates that, although the birds may be 

 able to fly quite well in a straight line, they are incapable of making any sudden turn or 

 performing any rapid aerial evolutions. The oesophagus is wide but without any dilatation 

 or crop. The proveutriculus is. well developed. The stomach is large but not muscular. 

 Although the fold of the duodenum is long, yet the pancreas is generally small. There 

 are two cooca of quite a large size with the blind ends dihited. The females are larger 

 than the males. 



FAMILY I. STRIGID^. THE DISKED OWLS. 



Marginal- indentations, two, wide hut not deep. Tarsus, long. Eyes, small. Facial 

 disk, perfect. 



The marginal indentations are simple, shallow scallops. The size is not very large. 

 The bill is rather long. The tarsi are comparatively long and the feet large. The plum- 

 age is rather light in color and of a peculiar, soft, downy structure, not as observable 

 in other families. 



