The dark color of the upper parts, restriction of the color of the underparts on the ankles with the result that the color reaches the toes in interrupted fashion, and large skull, of no. 18912 of the Museum of the University of South Dakota, from Roberts County, South Dakota, clearly place this specimen with _spadix_, rather than with _longicauda_. Likewise, male, subadult, no. 11376, Univ. South Dakota, from Clay County, South Dakota, is referable to _spadix_. Although without external measurements, the specimen obviously is large. The patch of summer pelage on its head and neck is darker than the summer pelage of _longicauda_, and the orbitonasal length is greater than the length of the tympanic bullae; all these features are characters of _spadix_. The adult male from Fort Sisseton, South Dakota, no. 188407, United States National Museum, figured by Merriam (1896, p. 20, figs. 7-9), is almost exactly intermediate between _longicauda_ and _spadix_, although here referred to the latter. Five specimens, nos. 147375, 147432, 147762, 148720 and 148721, U. S. Nat. Mus., including 3 skulls only from Beemer, Cuming County, Nebraska, are intergrades between _M. f. longicauda_, _M. f. primulina_ and _M. f. spadix_. One skin is in white winter pelage and the other, a female, is in summer pelage which in coloration and color pattern agrees with that of _spadix_. External measurements of the male agree with those of _longicauda_. Measurements of the female agree with those of _spadix_ except that the tail is shorter as in _primulina_. The skulls are as long as in _longicauda_ but are more slender than in either _longicauda_ or _spadix_ although nearer the latter in this respect. In dorsal aspect, the skulls especially posteriorly to the orbital region, resemble _primulina_. All points considered, the animals seem best referred to _spadix_. Although the degree of development of certain morphological features has been settled upon as indicative of the race _spadix_, some doubt remains as to where the western boundary of its range should be shown. This results from the fact that color has been taken into account as one diagnostic feature and this feature is lacking in the white winter specimens which, from the following places, are all that are available: Kittson County, Minnesota; Moorhead, Minnesota; Casselton and Valley City in North Dakota; Armour, South Dakota and Clay County, South Dakota. In summary, more specimens in the summer coat will be required to establish definitely the boundary between the ranges of _longicauda_ and _spadix_. Surber (1932:49) has referred to additional specimens of this weasel in the University of Minnesota Museum as from Winona, Hennepin and Isanti counties of that state.