﻿xxxvi INTRODUCTION. 



the river Ohio, where its remains occur associated with the mastodon at "Big-bone 

 Lick/' In the College of Surgeons there are some very characteristic remains from this 

 latter locality. 



§ 9, 1. Glires. — Genus Castor. Species Castor trogontherium, Cuvier. — Jaws and 

 numerous isolated teeth from the Forest Bed of Bacton and Mundesley, and the blue clay 

 of Cromer, prove the former existence of the great extinct species of beaver first found by 

 M. Fischer on the sandy borders of the Sea of Azof, at the beginning of the present century. 1 



Species Castor Uuropceus, Owen.— The existence of a species of beaver that cannot be 

 differentiated with that now living in the Rhone and Danube, with the great extinct C. 

 trogontherium, is proved by the occurrence of its remains in the same series of deposits at 

 Mundesley, Happisburgh, and Thorpe, on the Norfolk coast. A ramus from Grays Thur- 

 rock, preserved in the British Museum, and the entire lower jaw from Ilford, in the cabinet 

 of Dr. Cotton, F.G.S., prove also that it was a contemporary of the leptorhine, megarhine, 

 and tichorine rhinoceroses, of Mephas primigenus, E. antiquus and B. prisons. In size 

 the remains coincide exactly both with the recent beaver, and with that that is found so 

 abundantly in and under peat-bogs. It has not yet been found in any of the British 

 Pleistocene caverns. 



Genus Arvicola. Species Jrvicola amphibia, Desm. — That the large water mole of 

 our streams lived at the same time as the great extinct carnivora, and pachyderms in 

 Britain is proved by the occurrence of their remains, both in caverns and river-deposits. 

 In Ban well Cavern it was associated with the great cave-bear, the reindeer, and the 

 panther ; in Kent's Hole, with machairodus ; in Kirkdale, with hyaena ; and in the river- 

 deposits at Ilford, Crayford, and Erith, with bison, lion, and the tichorhine, leptorhine, 

 and megarhine rhinoceroses. 



Soecies Arvicola pratensis. The Bank Vole has been found in Kent's Hole, in precisely 

 the same condition as the other Pleistocene remains obtained from that famous cavern. 



Species Arvicola agrestis. — The third species of Arvicola, the Field Vole, has also been 

 obtained from Kent's Hole, by the late Mr. MacEnery, and from the Hyaena-den at Kirk- 

 dale, by Dr. Buckland. 



Genus Mus. Species Mus musculus, Pall. — From Kirkdale Cavern has been obtained 

 the only evidence for the existence of the common mouse in the Pleistocene period. The 

 remains though, as Professor Owen remarks, slightly larger than the existing mouse, in 

 no other respect differ from that species. 



Genus Lepus. Species Zepus timidus, Erxl. — The remains of the common hare have 

 been discovered in the Men dip bone-caves, by the late Rev. D. Williams ; in Kent's Hole, 



1 ( c Cuvier,' torn, cit., vol. v, pt. i, p. 59.) The large size of the anterior molar, as compared with the 

 rest, and the absence of involutions of enamel on the outer side of the molars, with many other points, 

 differentiate the teeth of this species from the living Castor fiber of Europe and North America. Its remains 

 are confined to the localities mentioned above. 



