LITHORNIS VULTURINUS. 551 



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, c ; 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 Acci- 

 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 (Strigi&e), and the shaft of the same bone was too 

 slender for the Falconida ; the femur and tibia were, 

 likewise, relatively weaker than in most of our Hawks or 

 Buzzards. But in the small Turkey- Vulture (CatJiartes 

 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 



