In Chiroptera the pelvis is small and narrow, and in the great majority of cases the two halves do not meet in a ventral symphysis. The pubis has a strongly developed pectineal process, which occasionally unites with a process from the ilium enclosing a large pre-acetabular foramen.

Primates. In Man and the Anthropoid Apes the pelvis is very large and wide, and the ilium has much expanded iliac and gluteal surfaces. The symphysis is rather short and formed by the pubis alone. The acetabulum is deep and the obturator foramen large, and there is frequently a well-marked ischial tuberosity. In the lower Anthropoidea the ilium is long and narrow and has a small iliac surface. The ischial tuberosities are large in the old world monkeys.

Fig. 108. Left anterior and posterior limb and limb girdle of

Uintatherium mirabile. The anterior limb is to the left, the posterior

to the right × 1/10. (From casts, Brit. Mus.)

1. ilium.11. prescapular fossa.
2. head of femur.12. coracoid process.
3. great trochanter.13. humerus.
4. patella.14. radius.
5. fibula.15. ulna.
6. tibia.17. unciform.
7. second digit of pes.18. cuneiform.
8. ungual phalanx of fifth20. lunar.
digit of pes.21. first metacarpal.
9. calcaneum.22. fifth metacarpal.
10. postscapular fossa.

The Thigh and Shin.

In the Monotremata the femur is short, rather narrow in the middle, and expanded at each end. The great and lesser trochanters are large and about equally developed, but there is no third trochanter. The fibula is very large and is expanded at its proximal end, forming a flattened plate much resembling an olecranon. The patella is well developed.

In the Marsupialia there is no third trochanter to the femur, the fibula is well developed but not the patella as a general rule. Notoryctes has a femur with a prominent ridge extending some little way down the shaft from the great trochanter; the tibia has a remarkably developed crest, and the fibula has its proximal end much expanded and perforated; there is an irregularly shaped patella closely connected with the proximal end of the tibia.