XV BAMSTERS AND. COTLON, RATS 479 
hordes so familiar (as far as their description is concerned) to 
everybody. The Lemmings do not return from their exodus. 
They die from various causes, including combats with one 
another. Their chief foes, however, are Wolves and Gluttons, 
Buzzards and Ravens, Owls and Skuas, which batten on the 
migrant hordes. Their sudden increase in numbers recalls the 
similar increase at times of the Field-Vole, to which reference 
has already been made. 
Ellobius is an Old-World genus, which leads a “ Talpine ” life, 
and has in consequence rudimentary external ears and very 
small eyes. The tail is short. Contrary to what might be 
expected from its mode of life, the claws upon the digits are 
not strong. 
The remaining genera of Vole-like Murines are Phenacomys 
and Synaptomys from North America, and Siphneus from Palae- 
arctic Asia. Hvotomys is one of those genera which are common 
to both the Palaearctic and the Nearctic regions, but the bull of 
the species are North American. 
Sub-Fam. 9. Sigmodontinae.—This is the name given to 
another sub-family of Murine Rodents, a group which includes 
the Hamsters in the Old World as well as a large number of 
South American genera of Rat-like animals. Of these latter 
there are avery large number, the bulk of the group being 
American. 
The Hamsters, genus Cricetus, as it is usually called, although 
apparently the correct name is Hamster, are Old-World forms of 
Pouched Rats. The Common Hamster, C. frumentarius, 1s about 
210 mm. long, with a tail of 58 mm. It has. cheek pouches. 
The small and the large intestines are not very unequal in 
length, and the caecum is fairly large, being about one-sixth to 
one-seventh of the length of either. It is a purely vegetable- 
feeding creature, and in Germany where it occurs (and from 
which language its vernacular name is derived), hibernates during 
the winter in its burrow, having previously surrounded itself 
with a great accumulation of food carried thither. 
To North America are peculiar the genera Onychomys, Sig- 
modon, and Peromyscus. The genus Sigmodon, the Cotton Lats, 
reaches Central America, and even gets a little farther south. 
The other two genera, though mainly North American, also 
extend their range to the south. Onychomys has hairy foot- 
