(3) Bathyergidae, Cape Mole, etc.
(4) Spalacidae, Bamboo Rats.
(5) Geomyidae, Pouched Rats.
(6) Heteromyidae, Kangaroo Rats.
(7) Dipodidae, Jerboas.
(8) Pedetidae.
The Gliridae have no caecum, so usual in the Rodentia. It is true that all the genera have not been dissected, but it is known that in the true Dormice, as well as in the genus Platacanthomys, a caecum is absent.
Apart from these few exceptions the Mouse-like Rodents all possess a caecum, though it is often not very large. They are all smallish animals, and are modified to a great variety of habit and habitat. There are burrowing, swimming, and climbing forms. The group is universal in range, even including the Australian region, in which they are the only Rodents.
Fam. 1. Gliridae.—This family, also called Myoxidae,[[328]] includes the Dormice, and is entirely an Old-World family, absent only from the Malagasy region. Its most important differential character is the total absence of the caecum and of any sharp boundary between the small and large intestine. The molars are usually four. The eyes and ears are well developed.