62 Miller Description of a New White-Footed Mouse 



and body of a large male, 31 inches ; tail, 2 inches. In another 

 specimen, the head and body 3y\ inches; tail, If inches. In 

 spring the hairs of the upper parts are plumbeous at the base, 

 tipped with ashy and yellowish brown ; a few longer hairs, en- 

 tirely black, interspersed. The tips of most of the hairs deepen 

 into black along the back, giving a broad, black stripe when the 

 hair lies flat. In some specimens this stripe is not so dark as 

 in others, but is quite distinct in all, while in some it is pitch- 

 black." It will be remembered that one of the noticeable color 

 features of S. canadensis is the indistinctness-of the dark dorsal 

 stripe; hence Mus bairdii, whatever it really may be, is a very 

 different species. 



The animal from Burlington,Vermont, described by Baird under 

 the name of Hesperomysmyoidcs (Gapper) (Mam. N. Am., 1857, p. 

 472), is, in part at least, the same as the subject of the present 

 paper. Baird remarks that " all the white-footed mice from near 

 Burlington, Vermont, had much longer tails in proportion than 

 those from Middleboro, Massachusetts." The only specimens, 

 three in number, that I have seen from the locality in question 

 are, however, typical americamis. Baird 's statement, " tail verte- 

 brae generally .25 of an inch longer than head, and body witli a de- 

 cided pencil at the end," and also table of measurements on page 

 473, refer, without question, to the long tailed form ; but his descrip- 

 tion leaves a slight doubt as to just what animal he had in hand. 

 I have never seen a specimen of S. canadensis in which the color is 

 " more vivid yellowish brown " than in S. americanus, nor do 

 any resemble S. aureolas in color, as is said to be the case with 

 "H. myoides" Baird considered the presence of cheek pouches 

 to be the best diagnostic character of myoides. More recently, 

 however, it has been shown by Allen (Bull. M. C. Z., I, 1<S(>9, 

 229) that these structures occur also in the common S. ainrri<-<iiuix. 

 It is worthy of remark, in this connection, that I have found the 

 cheek pouches of S. canadensis much the more frequently and 

 conspicuously distended with food. 



Sitomys americanas canadensis is exclusively a Canadian form, 

 replacing S. americanus in the spruce forests of New Brunswick 

 (Restigouche county, E. A. Bangs; Northumberland county, (1. 

 S. Millc;*), and extending south among the hills and mountains 

 at least to central New York and western Massachusetts, tfifomi/x 

 americanus is found as far north as Oigby. Nova Scotia, and Lake 

 Simcoe, Ontario. Thus the ranges of the two forms overlap 



