3;34 Dr. Richardson on Aplodontia, 



Dr. Harlan has placed it in the genus Arctomys. It differs, however, essen- 

 tially from an Arctomys, not only in general habit and appearance, but 

 also in dentition, as it does, indeed, from all the Rodentia with which I am 

 acquainted. M. Rafinesque has given few details of the genus Anisonyx, 

 and says of the teeth, merely, that they resemble those of the Squirrels. 

 This character does not apply at all to the Sewellel, which was known 

 to Rafinesque only from Lewis and Clark's description. I have, there- 

 fore, been induced to constitute a new genus for the reception of this 

 animal, and as the specific name of rufa is quite inapplicable, I have 

 given it one derived from the general resemblance it bears to animals of 

 the hare kind. 



Lewis and Clark deriving their information solely from the natives, 

 and, perhaps, through an imperfect translation, appear to have con- 

 founded the Sewellels with a species of Myoxus, a very distinct animal, 

 and are mistaken in ascribing to it the habit of climbing trees ; neither 

 is it found in the neighbourhood of the Grand Rapids of the Columbia, 

 as they were told. It is a very local animal, confining itself to particular 

 spots, generally on the banks of rivulets flowing through small prairie 

 lands. In these places it forms large villages, whose areas are completely 

 hollow with their burrows. It is common on the Cowlidiske, one of the 

 northern branches of the Columbia, also in the district between Mount 

 St. Helens and Puget Sound, and on the sea coast between the Colum- 

 bia and Whitby's Harbour. 



Its food consists of vegetable substances, such as grass, the bulbs of 

 the Scilla ^seulenta, and the bark of fallen trees, &c. The female has 

 two litters of young in a season, and brings forth from three to five at a 

 time. Several tribes of Indians, particularly those inhabiting the coast 

 from the mouth of the Columbia northwards, form dresses of the skins 

 of the Sewellel. 



Aplodontia.* 



Char. Dental formula, incisors f , canines §:^, grinders f:|- ! 22. 



Incisors, very strong, flatly convex anteriorly without grooves, nar- 

 rower behind. Grinders simple, remarkably even on the crovms. The 

 first in the upper jaw, small, cylindrical, and pointed, is placed within 



* Th. «7rXoof simplex, oSovg dens. 



