Sub-Order 2. Dermoptera

Fig. 253.—Galeopithecus volans. × ⅓. (After Vogt and Specht.)

The family Galeopithecidae contains but one genus, which has been at times referred to the Lemurs, to the Bats, or has been made the type of a special order of mammals. It is better to regard it as an aberrant Insectivore—so different indeed from other forms that it requires a special sub-order for its reception.

Galeopithecus inhabits the Oriental region. It is a larger animal than any other Insectivore, about the size of a Cat, and has a patagium extending between the neck and the fore-limb, between the fore-limb and the hind-limb, and between the hind-limb and the tail. This patagium is abundantly supplied with musculature, but the fingers are not elongated as in the Bats for its support. In the degree of its development, however, the patagium of this creature is midway between that of Sciuropterus on the one hand, and the Bats on the other. It presents many remarkable features in its organisation. The brain is like that of the Insectivora in the exposure of the corpora quadrigemina by the slight extension backward of the cerebral hemispheres; but its upper surface is marked by two longitudinal furrows on each side, a state of affairs (in combination) which is unparalleled among the Mammalia. The teeth are peculiar by reason of the singular "comb-like" structure of the lower incisors. This, however, is an exaggeration of what is to be found in Rhynchocyon and Petrodromus, while the same style of tooth, though not so highly developed, characterises certain Bats. The Tupaiidae and certain Lemurs show what Dr. Leche regards as the beginning of the same thing. As in Tupaia also there is an indication of the characteristically Lemurine sublingua. The stomach is more specialised than in other Insectivores, the pyloric region being extended as a narrowish tube. There is a caecum. A peculiarity of the intestinal tract is that the large intestine is longer than the small.