The ilio-lumbar angle is about 110°. The ischium is, short; a section of it, as it leaves the acetabulum, is subtriangular; but immediately it becomes flattened fore-and-aft throughout its plane of 90° to the axis of ilium; then verging toward the pubic symphysis it becomes small. The tuberosity of the ischium is small and directed up.
The pubis, as it leaves the acetabulum, is sub-cylindrical, after this it is flattened in the same plane with the ischium. The bone as a whole is short, thin, and slightly curved on its own axis; its smallest part makes up the pubic symphysis, which is short. The thyroid foramen is a large oval, with its long diameter parallel to the axis of the ischium.
The acetabulum is large, subcircular, and deep, with prominent borders; especially the iliac, which is produced on its external extremity into a point; the ischiatic is deeply notched. From the wide ligamentous pit in the centre there runs a deep groove part way down the antero-external side of the ischium.
The anterior opening of the pelvis is a wide oval, with its longest diameter transverse.
Measurements of Pelvis.
| M. | |
| Transverse diameter of pelvis, including sacrum | 1·171 |
| Long diameter of ilium (from lower margin of the crest to sacral surface) | ·440 |
| Short diameter of ilium (from acetabulum to upper margin of crest) | ·393 |
| Length of acetabular border | ·125 |
| Length of ischium | ·220 |
| Width of ischium at tuberosity | ·124 |
| Length of pubis | ·196 |
| Greatest width of pubis | ·061 |
| Smallest width of pubis | ·027 |
| Long diameter of acetabulum | ·139 |
| Short diameter of acetabulum | ·118 |
| Long diameter of thyroid foramen | ·094 |
The Femur ([Plate VIII.], Fig. 4).—-The femur is short, with a small oval head, strongly compressed fore-and-aft. It is less out of the axis of shaft than in Proboscidea, and has no pit for the ligamentum teres. The shaft is straight and simple, much compressed transversely at the proximal extremity, becoming sub-cylindrical below.
The great trochanter is heavy, rugose, and strongly recurved; it is separated from the shaft by a wide and deep digital fossa. The second trochanter is a mere rudimental tuberosity. The condyles are nearly of an equal size, very convex, and are divided by a deep popliteal groove.
The condylar tuberosities are low, the internal sends obliquely a ridge three inches long, up and across the axis of the shaft at an angle of 45°, that forms the upper boundary of the popliteal space.