228 TEN YEAES IN SWEDEN. 



As it is very rarely that this animal leaves the fields of 

 drift ice, which form its peculiar home-, it is only accident- 

 ally that a specimen, generally a young one, is seen on any 

 Scandinavian coast. 



OEDEE 5. EODENTIA. 



The distinguishing marks of this order are the two large 

 chisel-shaped incisors in the front of each jaw, distinct from 

 the molars. 



GEOUP 1. Collar Bone Perfect. 

 Fam. 1. MUEINA. 



Molars *-f^, tuberculated with divided roots, or com- 

 posite without tubercles, and with open undivided roots. 

 Tail round, naked, always as long as the body, often much 

 longer. Hind toes 5 ; front toes 4, with a knob instead of 

 thumb. 



Gen. Sminthus, Keys, and Bias. 



Upper lip not cloven, covered with hair ; ears stand well 

 out of the fur, and are covered with hair. 

 41. SMINTHUS BETULINUS, Pall. Lang Svansad Buskmus. F. 

 Colour, yellow or rusty grey, with a small black 

 streak along the back j below, white-grey. Tail much 

 longer than the whole body. Ears one -third the length 

 of the head. Length of head and body, S-^-in.; tail 3^ in. 

 Tail so thickly covered with hair, that the rings could 

 not be reckoned. 



Such is a description of this species, the only one of the 

 genus yet known, whose proper home is Siberia, and which 

 has, strange to say, been added to the Scandinavian fauna 

 from one single specimen killed in Scania in 1835. 



Gen. Mus, L. 



Tail long, rings always apparent. Upper lip cloven up 

 to the nose. Ears long, standing well out of the fur, and 

 nearly bare. 



