SNOW OWL. 
117 
face, belly and vent, are white; femoral feathers white, long 
and shaggy, marked with a few heart-shaped spots of brown; 
legs also covered to the claws with long white hairy down ; rest 
of the plumage white, every feather spotted or barred with dark 
brown, largest on the wing quills, where they are about two 
inches apart; fore part of the crown thickly marked with round- 
ish black spots; tail crossed with bands of broad brownish spots; 
shafts of all the plumage white; bill and claws, as in the male, 
black; third and fourth wing quill the longest, span of the foot 
four inches. 
From the various individuals of these birds which I have ex. 
amined, I have reason to believe that the male alone approaches 
nearly to white in his plumage, the female rarely or never. The 
bird from which the figure in the plate was drawn, was killed 
at Egg-Harbour, New Jersey, in the month of December. The 
conformation of the eye of this bird forms a curious and inte- 
resting subject to the young anatomist. The globe of the eye is 
immoveably fixed in its socket, by a strong, elastic, hard, car- 
tilaginous case, in form of a truncated cone; this case being 
closely covered with a skin, appears at first to be of one con- 
tinued piece; but on removing the exterior membrane it is found 
to be formed of fifteen pieces, placed like the staves of a cask, 
overlapping a little at the base or narrow end, and seem as if 
capable of being enlarged or contracted, perhaps by the muscu- 
lar membrane with which they are encased. In five other difie- 
rent species of Owls, which I have since examined, I found 
nearly the same conformation of this organ, and exactly the 
same number of staves. The eye being thus fixed, these birds, 
as they view different objects, are always obliged to turn the 
head; and nature has so excellently adapted their neck to this 
purpose, that they can, with ease, turn it round, without mov- 
ing the body, in almost a complete circle. 
