1841. _Arvicola scalopsoides_ Audubon and Bachman, Proc. Acad. Nat. Sci. Philadelphia, 1:97, type from Long Island, New York. 1912. _Pitymys pinetorum scalopsoides_ Miller, U. S. Nat. Mus. Bull., 79:229, December 31. Hanson (Trans. Wisconsin Acad. Sci., Arts, and Letters, 36:124, 1944) reported two pine mice from near Prairie du Sac, in Westpoint Township, Columbia County, Wisconsin, as _Pitymys pinetorum scalopsoides_ but cast doubt upon their subspecific identity. He also reported pine mice from Blue Mounds, Dane County, Wisconsin. We have examined these specimens (Westpoint, Columbia County, 2--No. 544, skin only, UWDEZ, and No. 521, skin only, H. C. Hanson's private collection; Westpoint, Dane County, 1, No. 11620, UWZM; Vermont, Dane County, 2, Nos. 11674 and 11694, UWZM) and have compared them with topotypes of _P. p. schmidti_, and with specimens of _P. p. nemoralis_ and _P. p. scalopsoides_. The specimens from Columbia and Dane counties differ from _P. p. schmidti_ in the greater zygomatic breadth, and lesser height of skull. They differ from _P. p. nemoralis_ of comparable age in shorter tooth-row and generally smaller skull. The interorbital region, however, is wider. In all of the features mentioned above, the specimens in question agree with _Pitymys pinetorum scalopsoides_, to which subspecies they are here referred. Microtus pennsylvanicus aztecus (Allen) 1893. _Arvicola (Mynomes) aztecus_ Allen, Bull. Amer. Mus. Nat. Hist., 5:73, April 28, type from Aztec, 5900 ft., San Juan County, New Mexico. Allen (_loc. cit._) described this species on the basis of two specimens from Aztec, New Mexico, and three from La Plata, New Mexico. He characterized it as "Size large; pelage very full and soft; tail short; skull very narrow. "Above grayish brown with a tinge of pale buff; fur blackish plumbeous beneath the surface, tipped with pale yellowish brown, and varied with longer, projecting, black-tipped hairs; below grayish white, the fur plumbeous beneath the surface and tipped with white, giving a whitish gray effect. Feet dusky; tail dusky brown above, dull white below." Allen identified as this species "a large _Arvicola_ from Estes Park, Colorado, which I have before been unable to allocate. I am unable to find that it differs in any particular from the specimens from New Mexico." He pointed out also (_op. cit._:73-74) that "The type and only positively identified specimen of Baird's _Arvicola modesta_ [= _Microtus pennsylvanicus modestus_ (Baird)] from Sawatche Pass, Colorado, is a very young specimen in poor condition. An examination of a series of adult and young examples from the type locality will be necessary in order to determine its relationships to _A. alticolus_ [= _Microtus longicaudus alticolus_ (Merriam)] and _A. aztecus_."