CHARACTERS OF PUTORIUS VULGARIS. 103 



Specific characters. — Very small ; length of bead and body 6 or S inches ; 

 of tail- vertebra^ 2 inches or less ; tail-vertebne about one-fourth or less of 

 the head and body; tail slender, cylindrical, pointed at tip, which is con- 

 color or not obviously black ; under parts white, rarely, if ever, tinged with 

 sulphury; coloration otherwise as in P. erminea. Caudal vertebr:e 15 

 (Geirard). 



General characters and relationsMps of the species. 



To describe the general body-colors of this animal would be 

 to repeat, in substance, most of what is beyond said of P. erminea. 

 I find no differences susceptible of intelligible description ex- 

 cepting those given in the foregoing diagnosis, although, as 

 usual in this genus, there is considerable individual variation 

 in the shade of the mahogany-brown upper parts, in the details 

 of the line of demarcation with the white of the under parts, 

 and in the color of the feet, which appear to be indifferently 

 like the back or like the belly. I do not observe, however, in 

 any of the specimens before me, that the under parts are nota- 

 bly tinged with sulphury-yellow, as is frequently or usually the 

 case with F. erminea. They are quite purely white. 



The i)oints of this animal to which attention should be di- 

 rected in comparison with its ally, P. erminea, are the general 

 dimensions and the color of the tail. This member is both abso- 

 lutely and relatively shorter than in P. erminea; it is cylin- 

 drical, very slender, and usually terminates in a point, without 

 the slightest bushy enlargement. In most specimens, as in all 

 the European examples I have seen, there is no black whatever 

 at the end of the tail ; on the contrary, the tip is frequently 

 mixed with a few white hairs. In other specimens, however, 

 the end of the tail is dusky, as in No. 6491, from the Yukon 

 (Kennlcott) ', while in Xo. 3316, from Oregon (Wayne), the tip 

 is quite blackish. The tail-vertebrae range from rather less 

 than an inch in length to full two inches, if not a trifle more, 

 though the latter dimension seems to be rarely reached ; the 

 terminal pencil of hairs from ^ to J. According to Gerrard, 

 there are fewer (15) caudal vertebrae than in P. erminea. 



Accounts of authors are surprisingly at variance in assigning 

 dimensions to this animal. De Kay says in one place 12-13 

 inches (nose to end of tail), but this is probably a slip of the 

 pen, for his detailed measurements amount to 8.80 for head and 

 body and 1.80 for tail-vertebrie ; Audubon, 8; Bachman gave 

 7 inches, the tail- vertebrae 2. Baird gives 6 ; the tail from 0.83 

 to 1.60; the head, 1.45; fore foot, 0.58; hind foot, 0.92. The 



