Feb., 1910.] Ohio Species of Mice. 69 



sleeker and smaller in size and the tail is only about half as long 

 as in that species. While collecting in Madison county a colonv 

 of the northern pine mouse was found in a pasture where the 

 grass had grown rather high. As this was the 20th of November 

 preparations had been made for winter evidently. I could not 

 determine the number of specimens in the colony, but four of 

 different ages were taken and there were evidences of others. 

 Their nest was located under a split log lying with the flat side 

 down and was composed of a quantity of soft grass with evidences 

 of food material here and there. Runway's led from the nest in 

 various directions so that the mice had easy access to a supply 

 of roots and other vegetable food in the vicinity. One of the 

 specimens taken, a male, is adult and fully colored, a second 

 specimen, also a male, is nearly adult size but the pelage is that 

 of an immature individual, the other two are immature, not 

 more than half grown. 



Synaptomys cooperi Baird. Cooper Mouse. This species 

 even has a shorter tail than the pine mouse and differs from all 

 mice of the genus Microtus in having the upper front teeth 

 groved. The species in the field has a grayish appearance with 

 the under parts clearly lighter. It is quite widely distributed 

 in the state and in places is common. It occurs in nearly the 

 same situations as the meadow mouse and in one field at London, 

 Madison county, all three of the short-tailed mice here considered 

 were taken on the same date and within the space of a few 

 square rods. In Summit county I located a nest of this species 

 on top of the ground and anchored in a bunch of clover. This 

 nest only contained two young which were observed often until 

 the}' grew large enough to run; two young is common in the 

 species which would indicate that it is not as prolific as the 

 meadow mouse. The species is met with commonly by turning 

 logs in fields and thin woods but is not confined to such situations. 



Peromyscus leucopus noveboracensis (Fisher). Common 

 White-footed Mouse. There are at least thirteen variations :^of 

 P. leucopus recognized and named from different parts of North 

 America. Most of eastern United States is included within this 

 range and subspecies reach Arizona, Montana and Yucatan. The 

 species was described by Rafinesque from specimens taken in 

 western Kentucky, a region where two forms appear to inter- 

 grade making it necessary to apply the species name to specimens 

 that are to some extent intermediate. Rafinesque' s name has 

 been applied to the form which has the more southern range 

 while the form that is uniformly distributed over Ohio is given 

 the subspecies name noveboracensis. Recently Osgood has pub- 

 lished an exhaustive treatment of the genus Peromyscus giving 

 full information regarding all subspecies. This paper is one of 



