122 RODENTS OF IOWA 



to exclude light. In looking over the mounds of earth that have 

 been thrown out by the gophers, a slight depression about three 

 inches in diameter will be noticed ; this indicates the spot to begin 

 digging. 



Although success in trapping may not be met with on the first 

 few attempts, by a little persistence experience will be gained 

 and with it better results. Trapping is safe, sure, efficient, and 

 inexpensive. 



JUMPING MICE. 

 Family ZAPODID^E. 



The jumping mice of North America are found only in the 

 boreal and semi-boreal regions and are nowhere abundant, though 

 distributed from Hudson Bay to North Carolina and from Alaska 

 to New Mexico and California. In Iowa, two forms belonging to 

 a single genus have been recorded ; but they are not sufficiently 

 common to be considered of economic importance, and in many 

 places the capture of a specimen arouses considerable local in- 

 terest. 



HUDSON BAY JUMPING MOUSE. 



Zapus hudsomus hudsonius (Zimmermann). 



Dipns hudsonius Zimmermann, Geog. Gesch. Mensch. u. vierfiiss. 

 Thiere, II, 358, 1780. 



Bescription. — About the size of the common house mouse, but 

 with the tail and hind legs markedly longer and more slender; 

 color above tawny to yellowish brown mixed with darker hairs, 

 the bases of the hairs plumbeous ; a broad dorsal stripe running 

 from top of head to base of tail, is distinctly darker than the 

 rest of the upper parts; lower parts and feet white with usually 

 a distinct yellowish browai line separating the color of the upper 

 and under parts; tail dark above, whitish below. 



Measurements. — Total length, 8.00 inches; tail vertebrae, 5.00 

 inches; hind foot, 1.20 inches. 



In spring and early fall this mouse is noticeably darker in (»lor 

 than in summer and the dark dorsal stripe is in part obliterated. 



On account of its elongated tail and hind legs and its peculiar 

 method of locomotion when disturl:)ed, this mouse is not likely to 

 be confused with any of our other forms except the following 

 subspecies whose distribution in the state is apparently much more 

 limited. 



