'.14 MAMMALIA. 



Barton. Its agility is extreme, and it closes itself up within its burrow, and passes the winter in a state of lethargy. 

 The Gerbillus labradorius, Harl., or Mus labrad., Sabine, constitutes another. 



The Hamsters (Cricetus, Cuv.) — 

 Have teeth nearly similar to those of the Rats, hut their tail is short and hairy, and the two sides 

 of their mouth are hollowed (as in certain Monkeys) into sacs or cheek-pouches, in which they trans- 

 port the grain they collect to their subterraneous abodes. 



The Common Hamster ( Mus cricetus, Lin.). — Larger than the Rat, of a reddish-gray above, black on the flanks 

 and underneath, with three white spots on each side ; its four feet are white, and there is also a white spot under 

 the throat, and another under the breast ; some individuals are all black. This animal, so agreeably variegated in 

 colour, is one of the most hurtful in existence, on account of the quantity of grain which it hoards up, filling its 

 hole, which is sometimes seven feet in depth. It is common in all the sandy districts, that extend from the north 

 of Germany to Siberia. The latter country produces several smaller species. 



The Voles (Arvicola, Lacep.) — 

 Have three grinders above and below, like the Rats, but without roots, and which are each formed of 

 triangular prisms, placed alternately in two lines. [Their incisors (or tusks), unlike those of the pre- 

 ceding genera, are rounded, having an oval section.] They require to be subdivided into several 

 groups, viz. : — 



The Muskquash (Fiber, Cuv.; [Ondatra, Laceped.]), — < 

 Which is a Vole with semi-palmated hind-feet, a long, scaly, and compressed tail, of which one species 

 only is well known, — 



The Ondatra, Muskquash, or Musk Rat of Canada (Castor zibeticus, Lin. ; Mus zibeticus, Gm.) — As large as a 

 Rabbit, and reddish grey [the fur resembling that of the Beaver]. In winter they construct, on the ice, a hut of earth, 

 in which several reside together, passing through a hole in the bottom, for the roots of the Aeorus on which they 

 feed. When the ice closes their holes, they are necessitated to devour one another, i'his habit of building has 

 induced some authors to refer the Muskquash to the genus Castor. 



The second subdivision is that of 



The Ordinary Voles (Arvicola, Cuv. ; Hypudceus, Illig.), — 

 The tail of which is hairy, and about the length of the body [or shorter], without webs to the toes. 



The Water Vole (Mus amphibius, Lin.)— A little larger than the Black Rat, and deep greyish-brown ; the tail as 

 'cng as the body. Inhabits the banks of ditches, and burrows in marshy plains in search of roots; but it swims 

 and dives badly. [This species has been known to occasion much damage, by burrowing into the raised banks of 

 canals : in ">ther respects it is quite harmless, except that it lays up a store of potatoes, &c, in its winter retreat, 

 which is placed far from the water. Its ordinary food is green aquatic herbage. A black variety is not of 

 uncommon occurrence, in many parts of Britain.] 



The Alsacian v ole (Mies terrestris, Lin.) — Rather smaller than the last, with a shorter tail. It lives under 

 ground like the Mole, preferring elevated fields, where it excavates galleries, and removes the earth to some dis- 

 tance from the opening. Its magazines, which are principally filled with the roots of the wild carrot cut into two- 

 inch pieces, are frequently two feet in diameter. [It is not found in Britain.] 



Meadow Vole (Mus arvalis, Lin.). — Size of a Mouse, reddish ash-colour, the tail a little shorter than the body. It 

 inhabits burrows in the fields, in which it hoards up grain for the winter. By multiplying excessively, it sometimes 

 occasions great damage. [There are several nearly allied small European species, two of which inhabit Britain : 

 that known as A. arvalis in this country has the tail very short, and the ears inconspicuous ; A. pratensis or 

 ripicola is redder, with a longer tail, and more apparent ears ; it is less common than the other. Many more exist 

 in Asia and North America, of which it will be sufficient to notice] 



The Economic Vole (Mus mconomicus, Pallas.) — A little darker coloured than the foregoing, with the tail still 

 shorter. It inhabits a sort of oven-shaped chamber, placed under the turf, from which issue several narrow and 

 ramifying canals running in various directions ; other canals communicate with a second cavity, wherein it 

 amasses its provisions. From all Siberia. It is thought to have been also found in Switzerland and the south of 

 France, particularly in the potato fields. 



The Lemmings (Georychus, 111. ; [Lemmus, Link] ), — 



Have exceedingly short ears and tail, and fore-feet better adapted for digging. [In other respects, 

 they only differ from the Voles in being rather more heavily formed.] 



The two first species have five very distinct nails to their fore-feet, as in the Mole-rats and Helamyds. 



The Scandinavian Lemming (Mus lemmus, Lin.)— A northern species, the size of a Rat, with fur variegated black 

 and yellow : it is very celebrated for its occasional migrations in immense bodies. At these periods they are said 

 to march in a straight line, regardless of rivers or mountains ; and while no insurmountable obstacle impedes their 



