1900.] SHUFELDT—OSTEOLOGY OF THE STRIGES. 679 
it calls to one’s mind the skeleton of many of the diurnal Raptores, 
more than any other single part in the osseous framework of the 
Owls is wont todo. Some of the Accipitres, however, possess in- 
terrupted post-pubic elements; I have never observed this to be 
the case in any American Owl. But aside from this character, the 
general facies of the pelvis, say of such a species as Syrnzum nebu- 
/osum, or many others, reminds us very much indeed of the pelvis 
in certain species of Hawks. 
This does not as a rule apply especially to the sternum, nor yet 
to the shoulder-girdle. As we have already shown, the sternum in 
all of the Budonide is strongly two-notched upon either side behind. 
The outside pair of notches are usually very deep in representa- 
tives of the genus Syrnzum. 
Returning to Budo virginianus, we see that in the skeleton of 
the arm the humerus is the only pneumatic bone, and the long 
slender radius is interesting from the fact that it has the os promi- 
nens articulated with its distal extremity, and a peculiar little 
osseous arch is found upon the side of its shaft at the proximal 
third of its continuity (see Fig. 5, os. f. and oa.). 
The ulna is about three times the calibre of the radius, with the 
distal moiety of its shaft nearly straight, while the preximal half is 
gently arched. Bones of manus are all well-developed, but withal 
present us with no very striking characters. The differences seen 
in the expanded part of the proximal phalanx of index digit, re- 
specting Strix and Budo, have already been pointed out above. 
In the pelvic Limé we find all the bones nonpneumatic, and the 
points of interest to be the great length of the fibula and the pecu- 
liar form assumed by the tarso-metatarsus. 
The characters of the joints of the toes have already been com- 
mented upon above. With respect to the tarso-metatarsus, we 
again meet with a bone that agrees in some of its features with the 
corresponding part of the skeleton among some of the Accépitres. 
The hypotarsus is single, prominent and placed to the inner side of 
the shaft. Deeply and longitudinally excavated adown the entire 
posterior aspect of its shaft, it is only partially so in frent, and 
that for the proximal half of the bone. A bony bridgelet spans 
the latter excavation just below the head of the bone and to its inner 
aspect. This is also seen in Pandion among the diurnal Rapéores ; 
and in that form, too, we note a very perfect fibula—that is, for an 
ornithic type. Some other Hawks are not backward in that par- 
. ticular. 
