UNITED STATES GEOLOGICAL SURVEY OF THE TERRITORIES. 
MONOGRAPHS 
NORTH AMERICAN 
RODENTIA. 
BY 
: * ELLIOTT COUES, 
CAPTAIN AND ASSISTANT SURGEON UNITED SPATES ARMY, 
SECRETARY AND NATURALIST OF THE SURVEY 5 
AND 
JOEL ASAPH ALLEN, 
ASSISTANT IN TILE MUSEUM OF COMPARATIVE ZOOLOGY, CAMBRIDGE, 
SPECIAL COLLABORATOR OF THE SURVEY. 
WASHINGTON: 
GOVERNMENT PRINTING OFFIOE,. 
18 ii. 
Vil 
