3909 
RESTORATION 
OF 
APTORNIS DEFOSSOR. 
THE nearly complete sternum and pelvis of Aptornis defossor about to be described, 
in addition to the evidences of that bird given in a preceding Section’, afford grounds 
for attempting a restoration of the skeleton of this extinct species (Pl. XCIV.). 
The sternum, figured of the natural size in Pl. LXXXIX. figs. 2, 3, 4, presents a 
close family, if not generic, resemblance to that described and figured in Pl. XLVIII. 
figs. 5-8, in my first Memoir on the genus (p. 185), with regard to which, recognizing 
in it unequivocal characters of a Ralline type, closely resembling that of the wingless 
Wekas (Ocydromus), but of much larger size, I had doubts whether to refer the bone 
to the Notornis (subsequently recognized as a still existent species), or to the still larger 
Aptornis otidiformis, which is most probably extinct. 
In Tribonyx ventralis the length of the sternum is 2 inches, that of the femur is 
2 inches 3 lines. In Ocydromus australis the length of the sternum is 2 inches, that of 
the femur is 2 inches 8 lines. In Notornis* the length of the femur is 4 inches 10 lines. 
in Aptornis otidiformis® the length of the femur is 6 inches 3 lines. The length of the 
sternum described p. 198, and figured in Pl. XLVIII. figs. 5-8, is 4 inches 6 lines, mea- 
sured from the foremost part of the coracoid groove to the tapering hind end, which is 
not entire. Ido not suppose, however, that the missing portion would exceed 6 lines 
in length; and it might probably be less. An addition of 4 lines would make the 
sternum in question equal in length to the femur of Notornis, and 14 inch shorter than 
the femur of Aptornis otidiformis. I select the femoral bone of the hind leg for this 
test comparison, because it varies less in proportion to the trunk or general size of the 
bird than the more distal elements of the limb. A comparison of the metatarsus of 
Notornis with that of Aptornis instructively illustrates this principle‘. 
The contiguity of the bones, when discovered, of Aptornis defossor here described 
enables me to refer with confidence the sternum to that species, most probably to the 
1 Pp. 290. 2 Pl. LL. fig. 3. > Pl. L. figs. 3 & 4. 
‘ «On the Archetype and Homologies of the Vertebrate Skeleton,’ 8yo, 1848, p. 200, note, p. 202. 
28 
