'iMii'; I'lrviivMi': w 1 1 »( >'i'i:i) moi sk, 



Ix'in^ oxpaiidod posteriorly and th(; audital bulhu; arc; relatively 

 wider. The teeth are narrower and the posterior u{)per molar is 

 relatively smaller; coronoid proeess of the lower jaw is relatively 

 stronger. 



Range—The range of this species includes part of Ohio, most 

 of Indiana, Illinois and Wisconsin. The limits of its range are not 

 well known. In their list of 1893 Evermann and Butler were 

 unable to give any records of this si)ecies for the State, but put it 

 in the list of whose which probably occurred. Since then it has 

 been recorded by the writer from Newton County and by McAtee 

 from Bloomington. I have also taken it at Bascom, Ohio County, 

 and Chansler has taken two specimens at Bicknell, Knox County. 

 Osgood also records it from Denver, Miami County, I know of 

 no other records from the State, but these widely separated local- 

 ities show that the species is of general occurrence and failure to 

 report it from elsewhere is no doubt due, in part, to the fact that it 

 is often confused with the young of Feromijsciis leucopus, which it 

 closely resembles. 



Habits. — I have never obtained this species anywhere except in 

 the thick bluegrass. Dr. Hoy stated many years ago that it was 

 found only in the oak openings, but he seems to have held an erron- 

 eous idea concerning the identity of some of the mice which he 

 collected, and the specimens from the prairies were not dissimilar 

 to those from the open woods as he supposed. Indeed, the species 

 is undoubtedly of prairie origin and it is doubtful whether it oc- 

 curred in southern Indiana previous to the clearing of the forests. 



Very little is known concerning the habits of this species. In 

 general its habits are not dissimilar to those of P. leucopus when 

 the latter species lives under the same conditions, as it sometimes 

 does. The prairie white-footed mouse is a more delicate creature 

 and it doubtless has a somewhat more restricted field of activity. 



Genus Nyctomys Saussure. 



Xyctomys Saussure, Revue et Magasin de Zoologie, 2d Ser., 

 Vol. 12, p. 106, 1860. 



Dental Formula.— I, C, Pm, ^^l, M, :;i- = 16. 



Generic characters. — Size somewhat larger than the white-footed 

 mouse, smaller than the house rat; body slender; tail very long; 

 back bright reddish; under parts white. 



This genus is indigenous to Mexico, Central America and north- 



