82 RODENTS. 



to the east of the Rocky Mountains, and is entirely an inhabitant of open plains. 

 The length of the head and body usually varies from 11 J to 12 \ inches, and that 

 of the tail, inclusive of the hairs at the tip, from 4 to 5 inches. In colour the 

 upper-parts are reddish brown varied with grey, and the under parts yellowish or 

 brownish white, the tail being coloured like the back, but with a brownish black 

 tip. The Columbian prairie -marmot ((7. columbianus) is a smaller species dis- 

 tinguished by its much shorter tail, which is entirely white, and by the more 

 yellow tinge of the fur of the body. It occurs in the regions to the west of the 

 Rocky Mountains, ranging at irregular intervals from Columbia through Colorado 



THE PRAIRIE-MARMOT (j liat. size). 



and Arizona to the Sierra Nevada, and is a more mountain-dwelling animal than 

 the preceding, occurring at elevations of as much as ten thousand feet above the 

 sea. The Mexican prairie-marmot (C. mexicanus) is the largest of the three, and 

 is distinguished from the common species of the plains by its much longer tail, in 

 which the black at the tip is darker and extends for a greater distance. 



In general habits the prairie-marmots very closely resemble the 

 true marmots, but it is stated that there is a distinct difference in 

 this respect between the common and the Columbian species ; the burrows of the 

 latter being unprotected by a raised funnel-shaped entrance which is so characteristic 

 of those of the former. The following account of the habits of the Columbian 

 prairie -marmot is taken from the travels of Lewis and Clark, who write that 



Habits. 



