1842. =fuscus= (_Putorius_) Audubon and Bachman [= _Mustela frenata noveboracensis_], Jour. Acad. Nat. Sci., Philadelphia, 8: (pt. 2) 288. 1842. =pusilla= (_Mustela_) De Kay [= _Mustela erminea cicognanii_], Nat. Hist. of New York, Zool., Pt. 1, Mammalia, p. 34. This name was proposed for small weasels of 12 to 13 inches in length of which the tail amounted to a fourth of the same and although obviously applying in considerable part to the earlier named _M. e. cicognanii_ seems to have included some individuals of the also earlier named _M. f. noveboracensis_. 1843. =xanthogenys= (_Mustela_) Gray [= _Mustela frenata xanthogenys_], Ann. and Mag. Nat. Hist., 11:118, February, 1843, was applied to all of the long-tailed weasels of California that had light-colored facial markings. Merriam in 1896 suggested that San Diego was the type locality and in 1899 Bangs proposed the name _mundus_ for the California weasel north of San Francisco Bay thus restricting the application of the name _xanthogenys_. In 1936 Hall further restricted the application of the name and applied it to the long-tailed weasel of the big interior valley of California, pointing out that the name was correctly applied to this weasel of the big interior valley or possibly instead to the race named _munda_. 1844. =agilis= (_Mustela_) Tschudi [= _Mustela frenata agilis_], Untersuch. ü. die Fauna Peruana, p. 110, is a name applied today to the race of weasel of the Temperate Zone of the western Andes and intermountain valleys of Perú. 1851. =nigripes= (_Putorius_) Audubon and Bachman [= _Mustela nigripes_], Quadr. N. Amer., 2:297, 1851, applies to the black-footed ferret of North America. 1853. =agilis= (_Putorius_) Audubon and Bachman [= _Mustela frenata noveboracensis_], Viv. Quadrupeds N. Amer., 3:184, pl. 140. This name was proposed for the female in the mistaken belief that it was specifically distinct from the larger male for which several names already were available. Also Tschudi in 1844 had already used the name _Mustela agilis_ for a South American weasel. 1864. =aureoventris= (_Mustela_) Gray [= _Mustela frenata aureoventris_], Proc. Zoöl. Soc. London, 1864:55, pl. 8, February 9, 1864, is the name applicable to the dark-colored weasel of the Pacific coastal region of Ecuador and Columbia.