So far as it is comparable with living animals, the ilium is altogether avian, differing in being narrower; and the pubis and ischium are mammalian.
The upper anterior corner is the most elevated part of the acetabular border, as in the great Auk and some birds of vertical position of body, and many mammals.
| Case. | Comp. | Tablet. | Specimen. |
| J | b | 11 | 1—16 |
FEMUR.
[Pl. 8.]
Twenty-six specimens are mounted to illustrate the Femur. 10 are proximal ends; 16 distal ends. But in the series illustrative of species is an entire specimen of a right Femur 4 inches long. Fragments Nos. 3 and 12 show proximal and distal ends twice as large, but most of the examples are about the size of the entire femur.
It is a straight sub-cylindrical bone, flattened in front, a little compressed from front to back distally, and (in one type) compressed proximally from side to side behind. The distal articulation has a broad shallow channel passing down from the front and imperfectly separating two condyloid parts, which extend a little backward and are divided behind. The outer condyle extends a little outward, and so gives the outer side of the bone at the distal end an oblique compressed aspect like that which prevails among birds and many mammals. Proximally the shaft contracts suddenly and is produced upward, forward, and inward as a rounded neck, as long as in the femur of any mammalian carnivore, which expands rapidly at the end to form the hemispherical ball, which articulates with the pelvic acetabulum.
No. 1 shows a well-marked pit for the ligamentum teres at the back part of the ball. At the proximal end of the shaft below the neck is a large pit for the obturator muscle, and at the outer front angle a great trochanter. Proximally the bone can only be compared with the mammalian Carnivora, Quadrumana and Man; distally it is avian and mammalian.
In one genus exemplified by specimens 5-10 the obturator pit is not developed.
Sometimes the shaft is curved a little convexly, outward and forward.