82 MAMMALIA. 



any common character; the greater number had merely pointed lower 

 incisors, but even this was subject to exceptions. 



Gmelin has already separated from them the Marmots, Dormice, and the 

 Jerboas ; but we carry their subdivisions much further, from considerations 

 founded on the form of their grinders. 



ARCTOMYS, Gmelin.* 



The Marmots, it is true, have the inferior incisors pointed like those of the 

 greater number of animals comprehended in the great genus 

 Mus ; but their grinders, like those of the squirrel, amount to 

 five on each side above and four below, all bristled with points ; 

 accordingly, some species are inclined to eat flesh and feed upon 

 insects, as well as grass. There are four toes and a tubercle in place of a 

 thumb to the fore feet, and five toes to the hind ones. In other respects 

 these animals are nearly the direct reverse of the squirrels, being heavy, 

 having short legs, a middle sized or short hairy tail, and a large flat head, 

 passing the winter in a state of torpor, and shut up in deep holes, the entrance 

 of which they close with a heap of grass. They live in societies, and are 

 easily tamed. Two species are known on the eastern continent. One is 



Arct. alpinus. (The Alpine Marmot.) Large as a hare; tail short; fur 

 yellowish grey, with ash-coloured tints about the head. It lives in high 

 mountains, immediately below the region of perpetual snow. The Bobac 

 (A. bobac ; M. bobac, Lin.) is about the same size, of a yellowish grey, tinted 

 with red about the head ; it inhabits the low mountains and hills of Poland and 

 Kamschatka, and will dig its burrow in the hardest soil. 



America also produces several species. Arct. monax, Buflf. (The Maryland 

 Marmot.) Grey ; tail blackish, as well as the top of the head. 

 Arct. empetra, Pall. Less than the preceding; grey; red beneath. 



SPERMOPHILUS, Fred. Cuvier. 



We apply this name to those Marmots tliat have cheek pouches. The 

 superior lightness of their structure has caused them tobe called Ground 

 Squirrels. Eastern Europe produces one species : 



M. citillus. (The Souslik or ZizeL) A pretty little animal, of a greyish 

 brown, watered or mottled with white, the spots very small, which is found 

 from Bohemia to Siberia. It has a peculiar fondness for flesh, and does not 

 spare even its own species. 



North America has several species of them, one of which is remarkable by 

 the thirteen fawn-coloured stripes which extend along the back on a blackish 

 ground. It is the Thirteen-striped Souslik, Arct. ; \3-lineatns, Harl. ; or 

 Sciums 1 %-lineatus, Mitchell ; or Arct. Hoodii, Sabine. 



There is one of the Rodentia which it appears we must approximate to the 



Arctomys, Bear-Rat. 



