80 MARMOTS DORMICE. 



Tribe of Hals. 



25. The tribe of Rats is composed of a great number of small 

 Rodentia which resemble our common rats in the most impor- 

 tant parts of their organization, and are the most carnivorous 

 animals of this order. Their fore paws are in general termi- 

 nated by four toes which are well developed, and a tubercle rep- 

 resenting a rudimentary thumb ; on the posterior extremities 

 there are five complete toes. Most of them live in holes. 



26. The principal genera of this group are, the Marmot, the 

 Dormouse, the Rat properly so called, and tne Hamster. 



27. The Marmots Arctomys, (bear-rat,) or mountain rats, 

 (Plate 4, /?</. 9.) differ in many respects from the other gnawers 

 of the tribe of rats ; like the squirrels, they have five molar teeth 

 above and four below, all studded with points ; some of these 

 animals feed on insects as well as herbs. Their form is heavy 

 and squat ; the head is flat and thick, the ears round, the limbs 

 short and stout, the tail small, and their coat thick and coarse. 

 Their walk is clumsy, and they run badly, but they can flatten 

 themselves so as to pass through narrow openings. They dig 

 with readiness a deep hole into which many individuals retire 

 during winter, a season which they pass in profound lethargy, 

 covered in a bed of hay. On the approach of cold weather, they 

 close their hole by heaping up earth at its entrance ; they are 

 then very fat, and their fat serves for their nutrition during their 

 lethargy. They do not store provisions, and never wander far 

 from this hole. They live socially, and when the troop is out, 

 they place a sentinel upon some elevated point to give notice of 

 the approach of danger. 



28. The Common Marmot, Arctomys 0lpiniis, is found in 

 the Alps, just below the region of perpetual snow. The moun- 

 taineers go in the winter to take them in their holes ; they eat 

 them and sell their skins, at a low price, for common fur ; it is 

 this fur which the little Savoyards who beg their way in some 

 European towns, often carry with them. It is about the size of a 

 hare, and its coat is yellowish gray. 



29. DORMICE, Myoxvs, (rat with a pointed nose,) are pretty 

 little animals with soft fur, a hairy, or even tufted tail, and ani- 

 mated look, which, like squirrels, live on trees and feed on fruits. 



25. How is the tribe of Rats constituted ? 



26. What are the principal genera of the tribe of Rats ? 



27. What are Marmots? What are their habits? Do they hibernate ? 



28. Where is the common Marmot found ? 



29. What are Dormice ? What are their habits ? How are they distin. 

 guished ? 



