FOSSIL BIRDS. 



163 



being composed of two branches cemented together at their 

 two extremities, is very visible ; as also is the little osselet 

 which stands for a thumb. 



The bone of the first phalanx of the great toe is also formed 

 of two branches in this ornitholite, as in birds in general. The 

 osselet representing the little toe is preserved on one side of 

 it, and that of the last phalanx at its extremity. 



The posterior extremities are not nearly so well preserved 

 as the anterior : there are, in fact, but some parts of one only, 

 but notwithstanding this, it is impossible to mistake them for 

 anything but portions of the leg of a bird. 



There is a lower half of the femur, and a tibia almost 

 entire, with a small remnant of the peroneum engrafted on its 

 upper part, as in all birds. 



The impression of the second fossil skeleton on the stone is 

 so extremely faint, that it requires eyes well habituated to 

 such examinations to recognize it. Yet, when the idea is once 

 conceived that it is the skeleton of a bird, the different parts 

 soon develop themselves very sensibly. 



The sternum, cast a little aside on the stone, and an extended 

 left wing, are visible. 



The humerus, the fore-arm with scarcely any traces of the 

 radius, the hand, the last phalanx, or little end of the wing, 

 have left their impressions. 



There are some traces of the left shoulder-blade, some better 

 marked of the right, and the humerus of this side is almost 

 entire. 



Of the neck, but three vertebrae remain. 



The body has left but a shadowy impression between the 

 shoulder-blades, but the last ribs on each side are distin- 

 guishable enough. The pelvis and the coccyx are but barely 

 visible. 



All the right posterior extremity is perfectly to be recog- 

 nized, as is likewise the lower portion of the left. 



The third of these skeletons is, perhaps, the most complete, 



M 2 



