TN SHUFELDT—OSTEOLOGY OF THE STRIGES. [Dec. 7, 
I have just given above sinks far into the realm of details, but occa- 
sionally such descriptions are very useful, and it is hoped that it will 
be found to be the case in the present instance. 
There are at my hand two skeletons of the nestlings of the Great 
Horned Owl ( Budo virginianus) that I secured from alcoholic speci- 
mens presented me by Dr. Strode, of Bernadotte, Illinois. (See 
Pl. X, Figs. 1-4.) They were taken by him at the time the birds 
were on the point of quitting the nest to shift for themselves. Some 
points of great interest are to be observed in either of the skeletons 
of these Owlets, as in them all the separate osseous elements of this 
part of their economy are still individualized. For example, in the 
skull the small yet distinct orbito-sphenoids are seen to be ossified, 
and the basitemporal is beautifully defined. The basipterygoid 
processes are as well developed as we find them to be in an old bird 
of the same species; while the interorbital septum is at this time 
only performed in membrane. On the vault of the cranium the 
sutures among the parietals, frontals, and squamosals are in close 
contact for their entire marginal lengths; this is not quite the case, 
however, with the bones of the base of the skull. The otic ele- 
ments are likewise quite distinct, and the vomer has not as yet 
ossified. 
Passing to the remainder of the trunk skeleton, we note the usual 
state of building up, by their elements, of the various vertebre all 
throughout the spinal column ; and find, moreover, that ‘ree verte- 
braze enter into the formation of the pelvic sacrum. 
No bone at all is as yet to be detected in the sternum, although 
the clavicles are now quite perfectly ossified, completely united 
below, and the arch possesses no little strength. The remaining 
bones of the shoulder-girdle, as well as the ribs, are well on toward 
ossification, though in form they are still quite primitive. 
In the wing all the elements are thoroughly independent of each 
other, and the structure as a whole is always brimful of interest to 
me. We find that the os prominens has not yet ossified, and only a 
tiny nodule of bone can be detected either in the radiale or the 
ulnare. The expanded part of the proximal phalanx of index digit 
is entire, and all the finger-joints are pretty well ossified. 
With respect to the pelvic limb we observe that the proximal ex- 
tremity of the femur presents but a club-like end, and no hint is as 
yet betrayed of the formation in bone of its head, neck or the 
trochanter. At least three bony ossicles are to be discovered in the 
