Fig. 46. Sternum and Associated Membrane bones of a Crocodile (C. palustris) × 1/3. (Brit. Mus.)
The last pair of abdominal ribs which are united with the epipubes by
a plate of cartilage have been omitted.
| 1. interclavicle. | 4. abdominal splint rib. |
| 2. sternum. | 5. xiphisternal horn. |
| 3. sternal rib. |
The abdominal splint ribs.
Lying superficially to the recti muscles of the ventral body-wall, behind the sternal ribs, are seven or eight series of slender curved bones, the abdominal ribs (fig. 46, 4). Each series consists of four or more bones, arranged in a V-like form with the angle of the V directed forwards. They show a considerable amount of variability in number and character. They are really membrane bones, and are in no way homologous with true ribs, but correspond rather with the more posterior of the bones constituting the plastron of Chelonia.
2. The Appendicular Skeleton.
This includes the skeleton of the two pairs of limbs and their respective girdles.
Fig. 47. Left half of the pectoral girdle of an Alligator (Caiman latirostris) × 2/3. (Brit. Mus.)
| 1. scapula. | 3. interclavicle. |
| 2. coracoid. | 4. glenoid cavity. |