Accordingly, the name _xanthogenys_ would seem to apply to one of the two subspecies here called _munda_ and _xanthogenys_. Perusal of Belcher's narrative of the voyage (_loc. cit._) shows that little, if any, opportunity was afforded to obtain vertebrate specimens at Fort Ross or Bodega, both localities within the range of the subspecies here called _munda_. Furthermore, the type specimen is smaller than individuals of _munda_ from 5 to 6 miles west of Inverness and from Point Arena with which the animals from Fort Ross and Bodega would be expected to agree in size. Weasels from along the north shore of San Francisco Bay are smaller than those on the coast north of the bay. Possibly the type specimen of _xanthogenys_ came from the north side of San Francisco Bay but probably it came from the bank of the Sacramento River and almost certainly not farther up stream from San Francisco Bay than the junction of the Sacramento and Feather rivers. The statement of Belcher (1843, vol. 1, p. 129), regarding the trip up the Sacramento River as far as Point Victoria, lat. 38°46´47" north, and return to San Francisco Bay, that "Cuyote or jackal--fox, racoon, land otter, weasel, and squirrel were obtained" lends strong probability to the idea that this type specimen was taken along the Sacramento River, possibly in the vicinity of the existing city of Sacramento. Unfortunately no specimens are available from the Sacramento Valley. If some were available, a comparison of them and specimens of _munda_ from along the north side of San Francisco Bay and Carquinez Straits with the type specimen of _xanthogenys_ should determine the correct application of the name. For the present it seems best to retain the name _munda_ and apply the name _xanthogenys_ to the weasels inhabiting the northern part of the San Joaquin Valley and presumably the southern part of the Sacramento Valley. Efforts to obtain specimens of weasels from the Sacramento Valley have been in vain. A juvenal specimen taken five miles south of Fair Oaks, Sacramento County, by Mr. John Fitzgerald, Jr., in December, 1927, was examined at his home and found to agree in coloration with specimens from farther south. Geographically, this specimen probably is more nearly a topotype than any other examined.