LITHORNIS VULTURINUS. Do: 
sternum either entire or with shallow posterior emargina- 
tions. Between the fossil and the corresponding parts 
of the skeleton of such birds, a close comparison has been 
instituted in regard to many minor details and modifica- 
tions, — as, for example, the secondary muscular impres- 
sions and ridges on the broad outer convex surface of 
the sternum; its costal margin and anterior angle, a; the 
form and extent of the coracoid groove, g; the conform- 
ation of the sternal end of the coracoid bone, ¢; together 
with the form and relative size of the preserved articular 
extremities of the femur and tibia. But, without repeat- 
ing all the details of these comparisons, it may be sufficient 
to state that, after pursuing them from the Sea-Gull and 
other aquatic species, upwards through the Grallatorial 
and Passerine orders, omitting few of the species and 
none of the genera of these orders, to which belong 
British birds approaching or resembling the fossil in size, 
the greatest number of correspondences with the fossil 
were at length detected in the skeletons of the Acei- 
pitrine species. 
The resemblance was not, however, sufficiently close to 
admit of the fossil being referred to any of the existing 
native genera of Raptorial birds. The breadth of the 
proximal end of the coracoid removed the fossil from the 
Owls (Strigida), and the shaft of the same bone was too 
slender for the Falconide; the femur and tibia were, 
likewise, relatively weaker than in most of our Hawks or 
Buzzards. But in the small Turkey-Vulture (Cathartes 
Aura), besides the same general form of the bones, so 
far as they exist in the fossil, there is the same degree of 
development, and the same direction of the intermuscular 
ridge on the under surface of the sternum, which divided 
the origins of the first and second pectoral muscles. The 
