164 BULLETIN OF THE 



length of tail and coloration, as well as in intrinsic value of the fur. The 

 white-headed varieties of New York are most like the sable ; the darker- 

 headed ones of the Western country like the pine marten." He is "in- 

 clined to the belief," he says still later, in an interpolated note, '-that we 

 have two species, one representing the pine martin, with dark head, the 

 other similar to the sable, with whitish head, — both probably distinct 

 from the corresponding Old World species, the martens at least." 



In Dr. Brandt's diagnosis of the martens, the relative length of the tail is 

 dwelt upon as an important character. Ln M. zibellina the tail without 

 the hairs is given as one third the length of the body ; in .1/. martes, one 

 half or more than one half. Professor Baird says the tail vertebras in M. 

 americana are about one half the head and body ; hence not differing much 

 from the same proportion in M. mart's, while quite different from the same 

 in Af. zibellina, which Dr. Brandt considers the .1/. americana to most re- 

 semble; while Dr. Gray observes that the tail of some of Dr. Lord's speci- 

 mens from Western America is almost as short as it is in the Russian sable. A 

 marked discrepancy is evident in these statements, explainable on the ground 

 of the inconstancy of the distinction based on the relative length of the tail. 

 Brandt also states that the M. foina differs from M. martes somewhat in 

 general color (but apparently not essentially, considering the much wider 

 differences in this respect his varieties of M. zibellina present among them- 

 selves), and in having the tail generally longer, with more vertebrae. 

 Since, however, the number of tail vertebras is far from constant in most mam- 

 mals with this member considerably developed (as I have myself observed in 

 the mice, squirrels, ermines, and foxes), this latter character must lose 

 much of its weight till repeatedly verified. Dr. Gray says, in urging the 

 non-identity of the American and Old World martens, that "It is curious 

 that both Brandt and Baird seem to have overlooked the small size of the 

 last tubercular grinder, which separates the American from the Old World 

 pine martens " ; a fact he claims to have discovered. From variations I 

 have observed in this respect in our common Mephitis, it would be inter- 

 esting to know whether Dr. Gray has found this difference constant in a 

 considerable series, or whether the observation rests on a single specimen, 

 as, in the same connection. In; refers to "the skull of the American speci- 

 men we have in the Museum," in speaking on another point. 



I have shown in the foregoing remarks that the martens and sables of the 

 Old World and the New are not without close points of affinity in all essen- 

 tial particulars ; that on both continents they present almost innumerable 

 differences, principally in respect to color, but few of which, if any, appear 

 to be geographical, or even constanl ; that on both continents the variations 

 are similar: that the points of distinction between the supposed species an' 

 slight, and rest mainly on characters which in mammals are the most likely 



