496 



RErORT OF STATE GEOLOGIST. 



Adults fawn color, with a very dark dorsal stripe; tail about two inches; 



skull small. hairdi, p. 502. 



Adults in fall and winter, bright rusty brown, with a broad median stripe 



of blackish. leucopus, p. 496. 



Adults similar, but with the brown more obscured by dusky tipped hairs 



and the dorsal stripe less distinct. novehoracensis, p. 497. 



PEROMYSCUS LEUCOPUS (Rafinesque). 

 WHITE-FOOTED MOUSE; DEEK MOUSE; WOOD MOUSE. 



Musculus leucopus Rafinesque, Amer. Month. Mag., Vol. Ill, p. 

 446, Oct. 1818. 



Hesperomys leucopus Baird, Mam. N. Amer., p. 459, 1857. 

 Calomys americanus Evermann and Butler, Proc. Ind. Acad. 



Sci. for 1893, p. 127. 

 Peromyscus leucopus Thomas, Ann. and Mag. Nat. Hist., 6th 



Series, Vol. 16, p. 192, 1895. Osgood, N. Am. Fauna No. 28, 



p. 113, 1909. 



Diagnostic characters. — Somewhat larger than the house mouse 

 and easily distinguished from it by the white under parts, large 

 ears and great protruding eyes ; it is less easily distinguished from 

 the other species of white-footed mice. 



Description. — Color dark, the middle of the back being very 

 slightly darker than the sides and face; underparts white with a 

 somewhat slaty basal region on the hairs; tail not very densely 

 haired; ears dusky, with a margin of whitish; hairs of ears short. 



Measurements. — Osgood gives the following measurements for 

 a specimen from Hickman, Ky. : Total length, 168 mm. (6% in.) ; 

 tail, 73 mm. (3 in.) ; hind foot, 19 mm. (% in.). 



Skull and teeth. — As compared with the house mouse, the skull 

 is much larger. Rostrum long and narrow, with its lateral mar- 

 gins nearly parallel ; dorsal profile arched ; interorbital region con- 

 stricted; upper incisors narrow. The molars have the tubercles 

 of the crowns arranged in two rows. In old individuals these are 

 apt to be worn down smooth. The skull is slightly smaller than 

 that of the next subspecies. 



Range. — As defined by Osgood the range of typical leucopus is 

 from southwestern Indiana to Louisiana and from eastern Virginia 

 to Oklahoma. He does not give any positive records from Indiana, 

 but mentions New Harmony specimens as being "doubtful" in 

 position. His selection of a type locality just within the edge of the 

 range of a form which he re-defines, is unusual, and it remains to 

 be seen whether other mammalogists will acc.c^pt his conclusions. 



