RATS AND MICE. 
59 
over the whole world, and externally presentino- few striking 
differences between the various species, liats generally have 
large ears, long and more or less scaly tails, and bright promi- 
nent eyes. They have a variable number of premolars (0-il), 
a flattened lower jaw, no slits in the bony palate, processes 
behind the sockets of the eyes, long perfect chivicles, and the 
tibia and fibula of the leg joined to each other about half- 
way down (fig. 33). 
Fig’. 83. 
Jjones of tlie lo’wer part of the Ilind-leg’ of the Rat, 
/, fibula ; t, tibia. 
The following families are included in this section : — The 
Gliridw or Dormice, beautiful soft-furred, bushy-tailed little 
rodents, inhabiting Europe, North Asia, and Africa, of which 
one small species, the Common Dormouse, Muscardinus avellan- 
arius ( 775 ), is a native of England. 
The Murid(t\ or Rats and Mice, of which may be mentioned the [Oases 
Gerbilles of India and Africa, Gerhillus or Tatera (794 to 796 ), 
and allied genera with elongated hind-feet, on which they jump 
like kangaroos; the Rats and Mice of the Old "World [Murimp), 
and the Hamsters and American Yesper-Mice (Cricetitur) ; 
the Voles (Microtus) , of which the best-known members are the 
common English Field-Mouse, AL ap/restis, and the YOater-Rat, 
AL ampluhms, both shown in the British Saloon ; and their near 
relative the North American Musquash, Fiber zibethicus ( 873 ), 
a beautiful example of which is exhibited in cases 11, 11 A, and 
11 B. Among the most remarkable members of ihe Alurida: 
