_Remarks._--Before the subspecific name _bangsi_ was proposed, individuals of this subspecies ordinarily were recorded in the literature as _Mustela cicognanii_. The best single lot of material is in the zoölogical collection of the University of Wisconsin. The late naturalist Albert Lano preserved a large share of the material from Minnesota. The large series from Elk River of that same state was mostly collected by Bernard Bailey although his Aunt, Anna (Bailey) Mills, and her brother the late Vernon Bailey, at an earlier time saved some specimens from Elk River. The name _bangsi_ was proposed in recognition of the superior work done on American weasels by the late Outram Bangs. From the range of _M. e. invicta_ in the Rocky Mountains, that of _bangsi_ is separated by the Great Plains from a large part of which region the species is unknown. _M. e. bangsi_ differs from _invicta_ in greater degree of sexual dimorphism in size, and in each sex by larger size, narrower light-colored underparts, and deeper braincase as measured at the anterior margin of the basioccipital. In _bangsi_ the braincase is deeper relative to the length of the skull as well as, of course, actually deeper. Of the two subspecies whose ranges do meet that of _bangsi_, it more closely resembles _richardsonii_ than _cicognanii_. From _richardsonii_, especially from southeastern populations of the same in which the skull is of the same size as in _bangsi_, the latter differs in longer hind feet. This is an average difference and by one interpretation the animals here referred to _bangsi_ might be lumped with some of the populations from the southeastern part of the range of _richardsonii_ and the whole lot treated as intergrades between _richardsonii_ and _cicognanii_. Nevertheless, the animals here referred to bangsi are not geographically intermediate between _richardsonii_ and _cicognanii_ and this consideration had much to do with the decision to recognize as a separate subspecies the animals here named _bangsi_. Within the range of the subspecies there is some geographic variation; the hind feet of animals from Iowa average slightly shorter than those of animals from Minnesota and Wisconsin but are nowhere nearly so short as in _cicognanii_ at the same latitude in the eastern United States. It is noteworthy that the few specimens seen from Isle Royal have the long hind feet of _bangsi_ and not the short hind feet of _cicognanii_ which occurs all along the northern mainland.