112 DR. J. E. GRAY ON THE MUSTELID#. [Jan. 24, 
Putorius fuscus, Aud. & Bachm. N. A. Quad. iii. 234, t. 148. 
P. cicognani, Baird, M. N. A. 161. 
P. longicauda, Richardson, Zool. Beechey, t. 10, 1839. 
Mustela (Putorius) erminea, var. long-tailed, Richardson, F. B. 
A. 46, 1829. 
M. longicauda, Bonap. Mag. N. H.1838, p.38; Gray, List Mamm. 
B. M. 195. 
Hab. North America, Carlton House. B.M. 
Bonaparte, Richardson, and Baird have separated the Weasels 
and Ermines of America and Europe into several species, on minute 
differences in the length of the tail as compared with the body. 
Dr. Spencer Baird, in his work on the Mammals of North America, 
divides the Stoats into six species, by the length of the tail and the ex- 
tent of the black on the tail. By his specific characters, the vertebree 
of the tail in P. richardsonii, P. noveboracensis, and P. longicauda 
is about one-half, in P. eicognani it is one-third, in P. ermineus one- 
fifth, in P. kaneii one-sixth the length of the body. 
When the bodies of several English Stoats have been compared, 
they show how deceptive that character is. I do not say that they 
may uot be distinct ; but, if they are, there must be other characters 
to separate them besides the mere length of the tail. They are 
spread over a large extent of country, and some of the presumed 
species have a large range. 
The skulls of the English Weasel and Stoat are also found to be 
rather variable when a large series of them are compared. 
They change colour when they live in a cold district, and the fur 
appears to become finer and denser in the more rigorous climates. 
Dr. Spencer Baird described P. novedoracensis as having 52 ver- 
tebree, including 4 sacral and 22 caudal; while P. ermineus has, ac- 
cording to him, only 19 caudal and 3 sacral, which are the ‘typical 
numbers in the genus. As this has only been observed on one skeleton, 
it may be only an accidental variation. 
2. MusTELA RICHARDSONII. Richardson’s Stoat. 
Dark chestnut brown; upper lips and legs entirely brown; chin 
and under surface white ; tail with a long black tip, depressed ; 
distichous. In winter entirely white ; tail-end black. 
Mustela richardsonii, Bonap. Mag. N. Hist. ii. 38. 
M. erminea, var., Richard. Faun. Bor.-Amer. 146. 
Putorius richardsonii, Richard. in Zool. Beechey Voy. 10; Gray, 
Cat. Mamm. List B. M. 195; Baird, Mamm. N. A. 164. 
Mustela erminea, Thompson, Hist. Verm. 31, 1842. 
Putorius agilis, Aud. & Bachm. N. A. Quad. 111, 184, t. 140, 
1833. 
Hab. North America: Fort Traveller (Richardson) ; from Halifax 
to Vancouver's Island ( Baird.) 
I have not seen this species; but Dr. Spencer Baird describes it 
very particularly. The quantity of white on the upper lip seems to 
vary. There is in the British Museum an adult female Stoat from 
Cambridgeshire, which has only a very thin margin of white to the 
