Fig. 40. A. Anterior limb of a young Hawksbill Turtle (Chelone imbricata) × ¼ (Brit. Mus.). B. Posterior limb of a large Green Turtle (Chelone midas) × 1/8 (Camb. Mus.).

1. humerus.12. femur.
2. radius (almost hidden by the13. tibia.
ulna).14. fibula.
3. ulna.15. tibiale intermedium and
4. radiale.centrale fused.
5. intermedium.16. fibulare.
6. ulnare.17. tarsale 1.
7. centrale.18. tarsale 2.
8. carpale I.19. tarsalia 4 and 5 fused.
9. carpale IV.20. first metatarsal.
10. pisiform.21. fifth metatarsal.
11. first metacarpal.I, II, III, IV, V, digits.

The Pelvic Girdle.

The pelvic girdle consists of three bones; a dorsal bone, the ilium, an anterior ventral bone, the pubis, and a posterior ventral bone, the ischium. All three bones contribute largely to the formation of the acetabulum, with which the head of the femur articulates.

The ilium is a small slightly curved bone, which unites ventrally with the pubis and ischium, and extends dorsalwards and backwards to meet the distal ends of the sacral ribs.

The pubis is the largest bone of the three; its distal end forms a wide bilobed plate, the inner lobe meeting its fellow in a median symphysis, while the other lobe or lateral process extends outwards. Attached to the symphysis in front is a cartilaginous epipubis, while behind, the two pubes are terminated by a wide rounded cartilaginous area.

The ischium, the smallest bone of the three, is flattened and like the pubis meets its fellow in a median symphysis. A narrow band of cartilage connects the symphysis pubis with the symphysis ischii, and separates the two obturator foramina from one another.

The Posterior Limb.