1 3 io THE RODENTS 



the bank for a distance of from ten to fifteen feet, when it expands into a large 

 chamber, in which may be a nest. Usually one or more galleries lead from 

 this chamber further into the bank. In certain districts where the water is deep 

 these animals in the autumn sometimes collect large heaps of vegetable matter in the 

 form of haycocks. Such heaps are known as "muskrat huts" or "houses." After 

 mentioning that some of those built in the water attain enormous dimensions, 

 Dr. Merriam observes that ' ' the summit of the structure is commonly high enough 

 out of water to admit of an air chamber within, which communicates with the out- 

 side world by means of a hole through the centre of the mass, the entrance or 

 entrances being under water. Many of the houses contain no mud or sticks, but 

 consist wholly of balls and knots of roots and swamp grasses. It seems clear that 

 the animals make no attempt to construct a dwelling of any particular shape, but 

 merely heap the materials together without plan or order, the resulting mound nat- 

 urally assuming, in a general way, the form of a flattened cone. . . . The 

 materials of which the hut are composed, it will be observed, are such as serve 

 as food for the animals during the long winters; hence the muskrat' s house is in re- 

 ality a storehouse, which he devours piecemeal as the winter advances." 



The nest is usually placed in a burrow in the bank, although occasionally in the 

 aforesaid hut. Here from five to nine blind and naked young are produced at 

 a birth, and it is reported that there may be as many as three litters in the course of 

 a season. 



Although not of much value, the fur of the musquash is much used, 

 both in America and Europe. According to Mr. Poland, from three 

 to four million skins come into the market annually; the Hudson's Bay Company 

 alone having sold over half a million in 1891. Dr. Merriam states that although the 

 flesh of the musquash is red and rather flabby, yet that, failing other meat, it 

 is eatable. 



THE MOLE-LIKE VOLES 

 Genera Ellobius and Siphneus 



Certain representatives of the vole group are specially adapted for a subterranean 

 mole-like life, and, therefore, differ considerably from the other forms, although 

 they retain the ordinary type of molar teeth. In form they are characterized by the 

 blunt and rounded head passing imperceptibly into the cylindrical mole-like body, 

 the absence of external ears, the short tail and limbs, and the broad feet, each pro- 

 vided with five claws. The incisor teeth project considerably, and their enamel is 

 usually white, instead of having the yellow or orange tinge so prevalent among the 

 ordinary voles. 



These mole-like voles, of which there are but few species, are mainly confined to 

 Central and Northern Asia, although one species ranges as far south as Afghanistan 

 and Quetta, and another extends into Eastern Europe. They are divided into two 

 genera, according as to whether the claws of the fore-feet are short or long; Ellobius 

 including the short-clawed and Siphneus the long-clawed species. The so-called 



