Page:Popular Science Monthly Volume 40.djvu/673

 hidden to a considerable extent by the hairs of the back, but fully visible from below, It is swelled out near the middle by two considerable lateral tuberosities. The fore feet are similar to those of the Chrysochlores. The two large arched and compressed nails of the third and fourth digits conceal the others, with the exception of the obtuse and corneous nail of the fifth digit, which is turned back and inserted at the base of the fourth. On examining the narrow palm of this paw, we can discover the thin, atrophied nails of the thumb and second finger. The palm is cleft, and the fingers form two groups: the outer, consisting of the third, fourth, and fifth; and the inner, of the first and second. The hind paws are likewise short and very thick, more robust than those of the Chrysochlores, spade-shaped, have the sole turned outward, are deeply grooved, and bare to the metatarsus. The first four toes are subequal; the fifth is represented by a short nail, much like that of the hand, and flanked by a large, broad, and flat sesamoid bone. The tibia is thick.

The dentition of the Notoryctes comprises forty teeth—ten in each branch of the jaws. The molars resemble those of the Chrysochlores,



having, like them, V-formed crowns; but the front teeth, especially the incisors, are much smaller than those of the Chrysochlores. This fact is remarkable, considering that the general form of the skull is also strikingly like that of the Chrysochlores. The median incisors are, like those of the Musaraignes and most of the placentary insectivores, scalpriformed, or thick and hooked like the teeth of rodents, and constitute strong organs of prehension which touch on the median line. On the other