92 MAMMALIA— ORDER V.—RODENTIA. 



may be either of medium length, or reduced to a stump. The coloration, 

 which is never like that of tlie chipmunks, may bo eitlier uniform or striped. 

 In habits, the susliks are social and burrowing animals, selecting dry sandy 

 soil for tlieir underground habitations ; and in the colder portion of their 

 range hibernating during the inclement months of the year. The common 

 American species is the striped gopher (& tridecemlineatus). Susliks agree 

 with the two following genera in that the incisor teeth lack the compressed 

 form characterising those of the squirrels and their immediate allies, and also 

 in tlie simple structure of their molars. The prairie-marmots, or prairie- 

 dogs (Cynomys) of North America form in some respects a connecting link 

 between the susliks and the true marmots, being intermediate in size between 

 the two, and having stouter bodies than the former. Their ears are small, and 

 the tail is generally short, while their cheek pouches are less capacious than 

 those of the susliks, and the first toe of the fore-feet is well developed, and 

 carries a large claw. The massive skull has the large postorbital processes 

 directed nearly outwards, and the stout molar teeth, which form two series 

 converging behind, difTer from those of both the susliks and marmots in 

 having three, in place of two grooves, on their crowns. In habits the prairie- 

 marmots very closely resemble the true marmots, but the mounds of 

 earth they throw up from their burnjws have a very distinct crater-like 

 form. 



From the prairie-marmots the true marmots {Ardomys) may be distin- 

 guished by their stouter form, the absence of cheek pouches, the rudimental 



first toe of the fore-foot, which carries only a 



small flat nail, and the above-mentioned 



differences in the form and direction of the 



upper molar teeth. Marmots are common to 



the northern half of both the Old and New 



World, ranging as far south as the Pyrenees, 



Alps, and Himalaya. They are among the 



larger members of the order, the common 



Alpine marmot measuring more than 20 



inches in length, exclusive of the tail. In 



appearance they are stoutly built, with short 



legs, powerful claws, a broad and short head, 



small and roundedears, and a bushy tail, usually 



less than half the length of the body. Their 



fur is moderately long, and somewhat stiff; 



while their colour exhibits various tints of 



Fig. 56. -Common Marmot goWen Or reddisli-brown, shading, more or 



(Arctomijs mannoita). less markedly into black along the back and 



tail, the tip of the latter being always 



blackish. As regards their habits, marmots live in extensive societies, their 



large and deep burrows forming warrens, and communicating with one 



another underground. All the regions they inhabit experience a very severe 



winter climate, during which the marmots hibernate securely in the depths 



of their burrows, only waking from their long sleep at the melting of the 



snows. Those that dwell in tlie mountains of Europe and Asia generally 



select open valleys or uplands, where the soil is more or less sand/, for the 



construction of their burrows, the neighbourhood of water being essential. 



In Russia and Siberia they inhabit the open and bai-ren steppes. Extreme 



wariness, especially where they dwell on frequented routes, is characteristic 



