230 BRITISH MAMMALS 



Spain and Portugal, except in the northern regions. It does 

 not seem to have been well known to the Romans in the past, 

 for the Latin name, Sciurus, is simply derived from the Greek, 

 Skiouros, a combination meaning "shadow-tail." There is also, 

 so far as I am aware, no recorded Anglo-Saxon or Celtic name. 

 The English word at present in use is, of course, derived 

 through Norman-French from Latin ; yet, as it is pretty certain 

 that the squirrel inhabited England continuously from the 

 Pleistocene Epoch, the absence of any reference to it before 

 the Norman Conquest is a negative argument in favour of the 

 rabbit being also indigenous. 



Spermophilus citillus. The Suslik ^ 



This is a squirrel-like creature with a short tail, which is, 

 no doubt, a transitional form between the squirrels and the 

 marmots. It inhabited England during the Pleistocene period. 

 The Suslik is represented in North America by a nearly allied 

 form called the gopher, which has a longer tail. The susliks in 

 both continents excavate and inhabit burrows. Both European, 

 Asiatic, and American forms have a tendency to a flesh diet, and 

 American gophers have become of late remarkably flesh-eating 

 animals. This is an interesting transformation in such Rodent 

 types as the squirrel, the suslik, and the rat, as the teeth of this 

 order were originally developed and differentiated solely with 

 a view to a vegetable diet. 



Family: CASTORID^. THE BEAVERS 



In the Beavers there are three molars in each jaw, but there 

 is only one pair of premolars in each jaw (as against an occasional 

 two in the upper jaw of squirrels), and the molar teeth are 

 rootless — a sign of specialisation. The tail is highly specialised, 

 being long, broad, flat, and covered with entirely hairless, scaly 



^ Remains indicative of the genus Spermophilus have been found in the 

 Thames Valley. It is not quite certain that these remains can be attributed 

 to the modern form inhabiting Central Europe and Northern Asia. 



