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 111 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 (0. 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 (| 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 
Habits. ® 1 J J 
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 
