Among other things that may have bearing on these questions, are these: Bonaparte in Charlesworth's Magazine appears to base the two names _Mustela Richardsonii_ and _Mustela longicauda_ on Richardson's published account of _Mustela erminea_. At any rate immediately following each of the two names, Bonaparte writes "Nob. (_M. erminea_ Rich. F. Bor. Amer.)." Bonaparte's other, first newly proposed name, _Mustela Cicognanii_, in Charlesworth's Magazine has following it only "Nob. North America," although in a paragraph above he did point out that this was the animal which all naturalists, at the time he was in America, considered as _M. vulgaris_. Turning to Richardson's account (Fauna Boreali Americana, ... Quadrupeds, pp. 45-47. 1829) one finds that he recognized two species, _M. vulgaris_ and _M. erminea_. Of the first he gives measurements "of an old female killed at Carlton House." Of the second species he distinguishes two varieties, the first represented by a specimen, of which he gives measurements, "killed at Fort Franklin, Great Bear Lake" and, the second variety "of a larger size, having a longer tail and longer fore-claws" he indicates the size of by giving measurements of a specimen taken "in the neighborhood of Carlton House." The last variety is clearly the basis of Bonaparte's _M. longicauda_. The specimen from which Richardson took his measurements I have been unable to locate [no. 43.3.3.3 in the British Museum, appears to be another specimen, although of the same subspecies and provided by Richardson]. The first variety of Richardson's _Mustela erminea_, clearly is the basis of Bonaparte's _M. Richardsonii_. The specimen from which Richardson took his measurements may well be no. 43.3.3.4 now preserved in the British Museum of Natural History, but I could not be certain about this. Richardson's _M. vulgaris_ is accompanied by measurements of a female which I have ascertained to my full satisfaction is the identical specimen now bearing catalogue number 43.3.3.5 said by Gray to be the specimen on which Bonaparte based his name _Mustela cicognanii_. Gray probably saw his guest, Bonaparte, at work on these weasels and Gray's own written indication perhaps should be accepted at its face value. I found only 4 Richardson specimens of North American weasel in the British Museum in 1937 and it is conceivable that Bonaparte, 100 years before, actually had at hand only one specimen each of two kinds and 2 specimens of the third. This I think is not an important consideration, though, for Gray says just which specimens did serve as basis for Bonaparte's names and there is only one specimen for each name according to Gray.