In the Ungulata the ribs are generally broad and flattened, and this is especially the case in the genera Bos and Bubalus (fig. 101, 6). The anterior ribs are short and nearly straight, and sternal ribs are well developed. The Artiodactyla have twelve to fifteen pairs of ribs, the Perissodactyla eighteen or nineteen, and Procavia twenty to twenty-two. The Elephant has nineteen to twenty-one pairs, seven of which may be floating ribs.

Fig. 101. Skeleton of a Cape Buffalo (Bubalus caffer).

The left scapula is omitted for the sake of clearness × 1/17. (Brit. Mus.)

1. premaxillae.7. femur.
2. nasal.8. patella.
3. orbit.9. tibia.
4. neural spine of first thoracic10. metatarsals.
vertebra.11. radius.
5. scapula.12. metacarpals.
6. rib.

In the Rodentia there are generally thirteen pairs of ribs, which do not present any marked peculiarities.

The Carnivora have thirteen to fifteen pairs of ribs, whose vertebral portions are slender, nearly straight and subcylindrical, while their sternal portions are long and imperfectly ossified (fig. 76, 5). There is nothing that calls for special remark about the ribs, in either Insectivora or Chiroptera.

Primates. In Man and the Orang (Simia) there are generally twelve pairs of ribs; in the Gorilla and Chimpanzee (Anthropopithecus), and Gibbons (Hylobates), there are thirteen, in the Cebidae twelve to fifteen, and in the Lemuroidea twelve to seventeen pairs. The first vertebral rib is shorter than the others, and the sternal ribs generally remain cartilaginous throughout life, though in man the first may ossify.

Appendicular Skeleton.