THE RODENTS OF IOWA 



Introduction. 



The present bulletin is offered to the people cf the state with the 

 object of giving such information as is available upon a group of 

 animals which is of considerable economic importance. The material 

 contained in Part I of the bulletin consists of brief diagnostic 

 descriptions of the various rodents known with certainty to occur 

 or to have occurred within the borders of the state, together with 

 something of their habits, distribution, economic importance and 

 also methods of control where such are deemed desirable. Most of 

 the measurements included in the descriptions are given in 

 inches. To avoid small and inconvenient fractions of inches 

 some small measurements are given in millimeters, a millimeter be- 

 ing equivalent to approximately 1-25 of an inch. The measure- 

 ments given for the various forms indicate the average; so that 

 specimens may be found which are somewhat below or above the 

 figures indicated. These measurements are taken in the follow- 

 ing manner: 



Total length. Distance from tip of nose to tip of tail vertebrae 

 not including the hairs. 



Tail vertebrae or tail. Distance from the point where the tail 

 joins the body to tip of tail, not including the hairs. 



Hind foot. Distance from heel to end of longest claw. 



In order to facilitate ready determination of groups and species, 

 simple keys based, for the most part, upon external characters are 

 added, and will be found in Part II of the bulletin. It is- hoped 

 that these identification tables will be found useful to individuals 

 as well as in schools where study of this nature can profitably be 

 taken HD, and it is further hoped that this paper may be of service 

 in creating among the people of the state a greater interest in the 

 wild life about them. 



The entire paper has been prepared with special reference to 

 the needs of the lay public, and an attempt has been made to make- 

 it as non-technical as possible without sacrificing too much that is; 

 seriously and strictly scientific. 



A further attempt has been made to give special consideration 

 to those rodents which are of economic importance to us. Any 



