126 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 
columns of which it is composed being pressed together so as to 
allow of no interval between them, whereas in the last two it is 
of the ordinary Arvicoline character; but they have four columns 
both externally and internally. The penultimate molar has three 
columns both externally and internally, and the anterior three in- 
ternally and four externally; and Z. torquatus is further distin- 
guished by a minute accessory posterior column to these two teeth. 
In all these characters the fossil closely agrees with ZL. torquatus, as 
well as in the form of the palatine aspect of the maxillaries and 
palatine bones, and of the naso-palatine foramen, whereas it differs 
from the other three species in these respects. The agreement in 
size between this upper jaw and the lower jaws last described is 
singular, and indicates the possibility that they may have belonged 
to the same animal; but as I have shown that L. torquatus and L. 
norvegicus belong to different sections of the genus, it is hardly 
probable that we have in the fossil an animal uniting the charac- 
teristics of the lower jaw of the one to the upper jaw of the other. 
We think it safer, for the present, to describe one as a small variety 
of L. norvegicus, and the other as a large variety of L. torquatus 
(Pl. VIII.) fig. 4, a. 
8. Genus Lagomys.—Lagomys speleus (Owen) has yielded two 
lower jaws—one from Hutton, found by Mr. Beard, and a second, 
found by Mr. Williams, which exactly corresponds in condition with 
it. Both are stouter than the specimens of Lagomys pusillus with 
which they have been compared; but the cave-Pika was certainly 
variable in this respect, and some jaws we have recently met with 
in Kent’s Hole do not appear to be larger or stouter than the small 
recent Siberian animal; in other respects they coincide: we there- 
fore consider it most probable that the cave animal was a variety 
of Lagomys pusillus. 
9. Genus Zepus.—In examining very numerous bones of Lepus 
which we have met with, which are found side by side with the 
bones of Elephas primigenius and its associated fauna, and com- 
paring them with those found in more recent beds, and with the 
bones of Lepus timidus, we have been much struck by the almost 
uniformly larger size of all the bones, particularly of the skulls of 
the more ancient animal. The same thing appears also to have 
struck the French paleontologists ; they have consequently named 
the larger and stouter form Lepus diluvianus (Pictet). 
A complete skull (Pl. VIII. fig. 5), many and considerable frag- 
ments of others, and a large number of lower jaws and of other 
bones have enabled us to make a comparison for which no previous 
opportunity appears to have existed. These bones are from Hutton, 
Banwell, and several other Mendip caves, as well as from Kent’s 
Hole and some other localities out of the county of Somerset. 
In the examination of the skulls of hares generally, when a large 
series of individuals, as well as of species, is compared, we have 
found that what at first might appear to be a specific difference is so 
frequently obliterated by individual variation, that it is extremely 
difficult to seize characters by which eyen entire skulls can be diffe- 
