The name _Mustela minor_ Nilsson 1820 was thought by Miller (1912:402) to be a renaming, and hence a synonym, of _Mustela nivalis_ Linnaeus. If that is the case the name does not apply to the dwarf weasel. If the name _Mustela minor_ Nilsson was instead based on the dwarf weasel, the name might still be unavailable, depending on rulings on secondary homonyms, because the name might be preoccupied by _[Lutra] minor_ Erxleben 1777 which is a synonym of _[Mustela] lutreola_ Linnaeus 1766. Two names seemingly available for weasels, and in use for them today, which might replace _rixosa_ as the name of the species, are, first, _Mustela boccamela_ Bechstein, 1801, of Sardinia [= _Mustela nivalis boccamela_ of Miller, 1912, 405] and second, _Putorius numidicus_ Pucheran, 1855, of Morocco and Algeria [= _Mustela numidica_ of Allen, G. M., 1939, 183]. As they stand in the current literature, _Mustela numidica_ is a species distinct from the dwarf weasel and the other name, _Mustela nivalis boccamela_, is an insular subspecies of the mouse weasel. Zimmermann (1943:292), however, implies that _M. numidica_ may belong to the dwarf weasel group when he says "Ob auch _iberica_ BARR.-HAM. als Unterart zu _minuta_ POM. zu stellen ist, soll hier nicht untersucht werden, ebensowenig die von CABRERA vermutete Zugehörigkeit der grossen nordafrikanischen _M. numidica_ PUCH. zur '_iberica_-Gruppe'." The answer to this problem requires a taxonomic, rather than a nomenclatural, decision. Whether either _M. numidica_ or _M. boccamela_ are conspecific with the dwarf weasel I cannot at this time ascertain for want of adequate specimens. Because these two names, _M. boccamela_, and _M. numidica_, are assigned to kinds of weasels which are currently regarded as specifically distinct from the dwarf weasel, and because all the other names which certainly have been assigned to Old World populations of the dwarf weasel before 1896, so far as I know, are _nomina nuda_ or are preoccupied, the next available name, _Mustela rixosa_ (Bangs, 1896), is here employed. _Remarks._--This species may have a wider geographic range in northeastern North America than is now known. Strong (1930:7) writes that the Naskapi Indians of the interior country of Labrador between Hamilton Inlet and Ungava Bay "have only one name for weasel, _mé-tah-kwut_, but they say there are three kinds in their territory, a large, an intermediate, and a very small weasel. The latter suggests the least weasel . . . which has not been recorded from northern Labrador."