THE SEWELLELSTHE BEAVERS 1267 



THE SEWELLELS 

 Family HAPLODONTID^E 



These North- American Rodents differ so remarkably from the other living forms 

 that they are regarded as constituting a family by themselves, of which the near- 

 est affinities are supposed to be with the Squirrel family. They differ from all the 

 members of that family by their extremely flattened and broad skulls, in which 

 there is no postorbital process defining the hinder part of the upper border of the 

 socket of the eye. The molar teeth have no roots, and the first pair of premolars 

 in the upper jaw are exceedingly minute. 



C mm ^k e common sewellel (Haplodon rufus} is an animal measuring 



Sewellel about a foot in length, exclusive of the stump-like tail, which measures 

 little more than an inch. The general color of the fur is brown, more 

 or less mingled with black, with the under parts grayish; the front teeth being yel- 

 low. The general form of the animal is short and clumsy, with the body relatively 

 large and cylindrical. Dr. Hart Merriam observes that "this singular animal, 

 which has come down to us as a relic of the past, and has no near affinities with 

 any existing group, inhabits a narrow strip of country on the northwest coast of the 

 United States. All the specimens thus far obtained have come either from Oregon 

 or Washington, or from the Chilukweyuk river near its junction with the Fraser, 

 in British Columbia." The animal lives in companies, constructing burrows in 

 moist ground. 



The Californian sewellel (ff. major] the mountain beaver of the 

 Californian _. 1 i \ ... 



inhabitants is a larger animal measuring sixteen inches in length, 



with grayish-brown fur above. These Rodents inhabit the Sierra 

 Nevada, and are largely aquatic in their habits. Mr. C. A. Allen, by whom the 

 species was discovered, writes that they "live in small colonies, and inhabit wet 

 ground where there is plent}^ of running water. They are very compact and strong, 

 with a head which resembles that of a pug-dog. They are very shy, timid animals. 

 On first seeing a human being, they try to hide away, but on being aroused are 

 savage enough. . . . They come out of their burrows about sundown to get 

 their food, and again at daylight in the morning." Mr. Allen proceeds to say 

 that the food of this sewellel is mainly composed of aquatic plants, especially the 

 stems of a water lily; and he adds that the burrows of these animals are always on 

 the lower part of a hillside, and frequently have running water passing through 

 them. Their feet are eminently adapted for grasping, and it is stated that these 

 creatures are in the constant habit of ascending broken and small trees furnished 

 with branches. They are generally captured by means of traps set in the water. 



THE BEAVERS 

 Family CASTORID^E 



From the large relative size of the animals themselves, coupled with their ex- 

 traordinary constructive and destructive powers, an amount of interest invariably 



