tion to a digging life is brought about in quite a different way from that of the true Moles (Talpa). In the latter the fore-limbs are changed in position by the elongation of the manubrium sterni, carrying with it the clavicles, which are extraordinarily shortened (Fig. 251). In Chrysochloris, on the other hand, the same need (i.e. that the limbs project as little as possible from the sides of the body, while the length of the limbs is retained, and the leverage of the muscles unaffected) is provided for by a hollowing out of the walls of the thorax, the ribs and the sternum being here convex inwards. The sternum and the clavicles are not modified. The tibia and fibula are ankylosed below. In the manus, moreover, there are but four digits, of which the two middle ones are greatly enlarged. In the Moles there are five fingers, and all are enlarged; there is, too, a great radial sesamoid bone, which is as good as a sixth finger (which, indeed, it is considered to be, in common with similar structures in other animals, by some anatomists). The foot has only four toes.
Fig. 249.—Golden Mole. Chrysochloris trevelyani. A, Lower surface of fore-foot. × ½. (After Günther.)
Fam. 7. Macroscelidae.[1]—This family contains three genera, all of them African in range, and mainly Ethiopian.
Macroscelides, the Elephant Shrews, are jumping creatures of Shrew-like appearance, combined with a Marsupial look. Both radius and ulna, and tibia and fibula, are ankylosed. There
- ↑ See Peters, Reise nach Mosambique, 1852, for external characters and anatomy.
