Voles, as typified by the water-rat and the tailed fieldmouse, are stouter built and shorter-nosed rodentsthan the typical rats and mice, with smaller ears and eyes and shorter tails; all being good burrowers.
The third sub-family is that of the Microtinae, or voles, which are distributed all over Europe, Northern Asia and North America, and are characterized by the tympanic bulla of the skull being filled with honey-combed bony tissue, the small size of the infra-orbital foramen, and the deep pterygoid fossa on the palatal aspect.
The reindeer, arctic fox (Canis lagopus), hare, wolf, lemming (Myodes obensis), collar lemming (Cuniculus torquatus) and two species of voles (Arvicolae) are the most common on land.
Admixture of Mongolian species, such as Canis corsac, Felis manul, Spermophilus dauricus, the jerboa (Dipus jaculus), two hamsters (Cricetus songarus and C. furunculus), three new voles (Arvicolae), the Tolai hare, Ogotona hare (Lagomys ogotona), Aegocerus argali, Antilope gutturosa and Equus hemionus (jighitai).
There are several varieties of grasshopper mice (Orychomys), white-footed mice (Peromyscus), harvest mice (Reithrodontomys), rice-rats (Oryzomys), wood-rats (Neotoma), voles (Microtus), &c. Bats inhabit caves in Burnet, Williamson, Lampasas, Gillespie and other counties.