ADDENDA. 



Messrs. Lewis and Clark, in the history of their 

 Expedition up the Missouri, have described, with 

 their usual accuracy, several new animals, which 

 have neither received scientific names nor assum- 

 ed that station in the systems to w^hich they pro- 

 perly belong. The first of these to which we 

 allude, are three species of the genus Arctomys^ 

 two of which inhabit the great plains of the Co- 

 lumbia river, from the Rocky Mountains to the 

 Pacific Ocean ; the other, the plains of Missouri. 



Mr. Rafinesque has attempted an arrangement 

 of these animals, by constructing from them a new 

 genus, which he names ^^ Anisonyx^^* and to which 

 he assigns the following characters. — " Teeth like 

 those of Squirrels ; no cheek-pouches ; five clawed 

 toes to all the feet, the two internal of which on 

 the fore feet very short, the three others long, with 

 very sharp nails ; tail distichous like that of Squir- 

 rels. (This genus differs from the Marmots and 

 the Squirrels in the number and form of the 

 fingers.") 



In the above description of Mr. Rafinesque; 



* Vid. AmericaTi Monthly Magazine, vol, ii, p. 45. 1R17 



