CHARACTERS OF PUTORIUS ERMINEA. 113 



separate the Ermine of America, being based upon P. ennUiea 

 of Eicbardson, who does not bint at any supposed distinction 

 from the Old World animal, and wbose description and 

 measurements indicate identity with ordinarj^P. erminea. Later, 

 the name was adopted by Prof. Baird for specimens from Massa- 

 chusetts and northward, considerably smaller than the average 

 (8 inches), but with proportions of body and tail much as usual. 

 P. agllis of Audubon and Bach man is obviously the same as 

 Baird's richardsoni. Specimens from Massachusetts and north- 

 ward, of about the same size, but shorter tail, were separated 

 by Baird as P. cicognani. He compares richardsoni with cicog- 

 nani as follows: — "This species is readily distinguished from 

 P. cicognani by the longer tail, the vertebrae aloue of which are 

 half the length of the body." Measurements of the tail-vertebr?e 

 of P. cicognani given range from 2.25 to 3.00. 



As a matter of fact, I find the tails to present all the several 

 dimensions given by Baird, together with other intermediate 

 dimensions, constituting an unbroken series from the shortest 

 to the longest; and with additional dimensions which connect, 

 them as closely with the largest examples of '' novehoracensis ". 

 It will be observed from Baird's tables that the difference 

 among the various examples of ^' cicognani^- (2.25 to 3.00 = 

 0.75) is about the same as that supposed to distinguish rich- 

 ardsoni (3.00 as against 4.00). In regard to total size, the same 

 minute gradations are before me, from specimens scarcely 8 

 inches long to others over 10. The points of relative lengths 

 of the black tip, amount of white on the upper lip, &c., are 

 wholly matters of individual variability, to be thrown out of the 

 discussion. It may be said in brief that the American Ermines 

 are inseparably connected by the most minute intergradations 

 from the smallest and shortest-tailed to the opposite extreme. 



This fact ascertained, liowever, should not blind us to the 

 equally notable fact of the existence of such differences. All 

 the points laid down by Baird are substantiated. There are 

 the larger and smaller Weasels, living side b^^ side, in Xew 

 York and Massachusetts, for instance — the one scarcely 8 inches 

 long, with the tail-vertebrie under 3, and the other 11 inches, 

 with the tail over 5. And I find the same thing to hold through- 

 out the country to the Arctic Ocean. The P. kanci of Baird, a 

 type of which is before me, is merely one of these smaller 

 Ermines from Arctic regions. The author indeed says it 

 is about the size of the P. cicognani, " which it otherwise greatlv 



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