

M 



124 



MONOGKAPnS OF NORTH AMERICAN RODENTIA. 



I :; 



i'J 



Ilcupiromyt hconiii, Waonkh, Wicg. Areli. 1S43, pt. ii, 51 (after Aud. & Bacli.). 



lUillirodon kcotilii, LkConth, Proo. Acnd. Nat. Sci. I'liila. vi, 18."3, 413 



r Mtt» caroliiiriiHia, Ai'D. & Hach., Joiirn. Acad. Nat. Sci. Phila. viii, pt. ii, 1842, 306 ; Q. N. A. iii, ia'>4, 3,12. 

 (.Suntli Cnruliiiu, iu iunndatcd lands, rare. "Tail longer than the body, ears long and hairy, 

 color liglit pltinibi'ons; * * nnder surface Hcarcely a shade lighter. Length of head and 

 boily ^.33, of tail 2.75, ear 0.33, tarsns 0.54.") 



f ITcuperomyii cttroliiiemie, Wao.nki!, Wieg. Arch. 1843, pt. ii, 51 (a''ter And. & Uach.). 



t r.iilhroion carolineum, IIaiiid, M. N. A. 1857, 4.")2 (after And. & Bach.). * 



llcUhrodon meiialolin, 1!aiiii>, M. N. A. 18.')7, 451 ; liep. U. S. and Mex. Bound. Surv. ii, pt. ii, 1859, Mam- 

 mals, 43, pi. vii, fig. 4a~c, and pi. xxiv, flg. 4a-g. (Sonora. Largest of North American 

 species. Head and body, 2j-3 ; tail, 2} ; sule, i-} ; oar, 0.43 high. Colors as ia B. humile.) 



Diagnosis. — O. mure musculo minor seu staturd suheequans, caudd trun- 

 cum suhcequante Iiirsutd, suh-bicolore, auriculis prominulin, himutis, plantis 

 semi-nudis, vfllere moUi, supra murino, infra griseo-alhido, lateribus fulves- 

 centihus. 



Habitat. — South Atlantic States. Gulf States into Sonora. Up the 

 Mississippi VuUcy to Saint Louis. Iowa. Kansas. Nebraska. 



Numerous e.xccllent examples, from the South Atlantic States, of this 

 diminutive Rodent, which, with the general appearance of a small house- 

 mouse, is instantly distinguished by its generic ciiaracters, present very little 

 variation cither in size, shape, or color. None show the peculiar proportions 

 attributed by Audubon and Bachman to their Mus carolinensis. The tail is 

 always a little shorter than the trunk. The hind feet range from 0.50 to 0.60 

 in length ; the ears project beyond the fur, and have a somewhat character- 

 istic shape, difficult to describe, represented with indifferent success in Audu- 

 bon's plate above cited. They are rather obovate in siiape, and narrow for 

 their length; the antitragus is valvular; the interior below is nearly naked 

 and flesh-colored ; this part is overlaid by tlie long hairs of the cheeks ; the 

 rest of the ear is rather coarsely liirsutc than closely pilous. The fur is soft 

 and silky; above, the color is exactly as in the house-mouse and nearly uniform, 

 being merely a little darker along the middle of the back ; but all along the 

 sides tlie brown is enlivened with a decided wash of fulvous or pin'wish-gray, 

 never seen in M. muisculus. Generally, this tinge is diffuse, but it sometimes 

 forms quite a striking lateral stripe. The tail is distinctly bicolor, but not 

 very sharply so. The under parts are whitish, obscured by the plumbeous of 

 the roots of the hairs showing through, and generally also noticeably washed 

 over with a dilution of the fulvous that tinges the sides. The lips, however, 

 arc pure while; and the whole oral and mental region, with the upper sur- 

 face of the feet, arc likewise white. The ab.solute size, and to some extent 

 the range of variation, of this species appear from the table given below. 



