Igo THE ESSEX NATURALIST. 
introduction and establishment of a foreign mammal in a wild 
state is a noteworthy event, and this is what has happened in 
recent years, or is in the course of happening, with the American 
grey squirrel; the present paper is an attempt to give some 
account of this. ; 
At the outset it may be remarked that although several of 
the mammals included in the British list are not native and 
came from foreign lands, namely, the rabbit, the fallow deer, 
and both the black and the brown rat, yet some two hundred 
years have passed since any species has succeeded in effecting a 
secure foothold and residence. The brown rat was the latest 
successful invader and it can be congratulated on certainly having 
made good, for itself, if not for us, 
NATIVE HAbITrat—-NAME AND DESCRIPTION, 
In its native region the North American grey squirrel, Scturus 
carolinensis, Gmelin, has a wide distribution, ranging from 
about 46° N in Lower Canada and New Brunswick to Northern 
Florida and westward to the edge of the plains. Mr. R. I. 
Pocock! says that there are several local races, two of which 
(a northern and a southern) are dominant, and that it is the 
northern form that we have received as our guest in the British 
Isles. 
This is distinguished by the name Sciurus carolinensis leucotis, 
but in the earlier period of tts time with us it was called S. 
cinereus, The latest authority has placed it in a separate genus 
and named it Neosciwrus carolinensis Gmelin’, but nomenclature 
need not detain us here and we shall be satisfied with S. cavolinen- 
sis as a working name, 
In external appearance the species differs very markedly 
from the native British species, the common or red or light- 
tailed squirrel, S. dewcowrus (Kerr), formerly called S. vulgaris 
(the latter name now being confined to the species which inhabits 
the Continent of Hurope and a large part of northern and central 
Asia), The grey squirrel is considerably larger than the red 
squirrel, about 11 inches in length as compared with 9 inches 
(in body), and in colour is uniformly greyish, grading from 
darker shades on the upper parts to whitish underneath. The 
1, The Feeld, asth January, 1922, p, 138. 
a. Hinton, History of British Mammals, Part ar, Octr,, roar, p, 718, 
