MUSEUM OF COMPARATIVE ZOOLOGY. 171 



mens from Eastern Massachusetts are given, both of which, in general size, 

 fall within the average of the twelve of P. Cicognanii; thus showing that 

 "small size " fails to sufficiently distinguish the latter, and also that short 

 tails and small size do not always go together in specimens from the same 

 locality ; the tails in these two exceed the average in the P. Cicognanii by 

 about thirty per cent, of the average of the whole series. The distinction 

 based on the relative length of the black tip seems also intangible, " two 

 fifths" coming just between " nearly one half" and " one third." To this 

 species he refers the P. agilis of Audubon and Bachman, and of course the 

 Muslela (Pulorius) erminea of Richardson, for which the name Richardsonii 

 was substituted by Bonaparte for erminea. Yet the dimensions given by 

 Richardson accord in the proportions of the tail to the body, not with 

 Baird's diagnosis of P. Richardsonii, but with that of P. Cicognanii, the 

 tail vertebra? being but little more than one third the body, and the hairs 

 and vertebra? together being less than one half.* 



Pulorius noveboracensis of Baird's Report is characterized as " Length to 

 tail about ten inches. Tail vertebrae about half this length. Black of tail 

 about half its length," etc. It thus diifers from the last only in being 

 larger. Yet one of the three specimens of which measurements are 

 given scarcely exceeds the size of the larger of the two specimens of P. 

 Richardsonii, and falls considerably below several of the P. Cicognanii in 

 length of body. One of the P. Cicognanii specimens even equals the aver- 

 age of those of P. Richardsonii, although P. Cicognanii, as previously ob- 

 served, is supposed to be distinctively characterized by its small size. 

 Some differences in the proportional length of the feet, and in the color, 

 are mentioned as existing between this and P. Richardsonii, but they are 

 evidently merely individual, and would disappear in a comparison of a 

 large series. To this species he refers the P. ermineus of Audubon and 

 Bachman and the P. noveboracensis of De Kay. 



In comparing some of the " noveboracensis " specimens with a short- 

 tailed one of the European P. ermineus, I am not surprised that Profes- 

 sor Baird found "very decided points of distinction," " notwithstanding the 

 assurance of authors " to the contrary. The principal one mentioned, how- 

 ever, is the greater brevity of the tail in the European, in which the pro- 

 portion of the tail to the body is about as it is in P. Cicognanii. 



In Pulorius hngicaudus the dimensions are given as, " Length to tail 

 about eleven inches. Tail vertebra? about half this length. Black of tail 

 about one fourth its length," etc. The measurements given of three speci- 

 mens average 10.78 inches in the length of the body, one only reaching 

 eleven, while the tail vertebra? alone equal fully half of this length. It 



* "Length of head and body, It inches; of tail (vertebrse), 4 inches; of tail, including 

 fur, 5 inches." — Faun. Bor. Am., Vol. I. p. 4". 



