240 e REPORT—1843. 
to a record of fossil Mammalia, to exemplify how readily and exclusively the 
remains of existing species and varieties of Mammalia, of which so few pre- 
sent themselves in the formations anterior to the human period, are detected 
when they occur in places of later date. 
In fens, turbaries and bogs, the remains of Mammalia indicate recent 
species, but such, for the most part, as have either existed but are now ex- 
tirpated in Great Britain, as the Wolf, the Bear, and the Beaver; or which 
still remain in a wild or domesticated state, as the Fox, the Wild Boar, the 
primitive short-horned Ox (Bos longifrons), the Goat, &c. 
In the freshwater marls beneath the bogs, and in similar deposits overlying 
newer pliocene strata with marine shells, we first meet with extinct species, 
as the Cervus Megaceros, Urus priscus, &c., belonging to genera which con- 
tinue to be represented in Great Britain or in Europe by existing species. 
The unstratified drift or ‘till,’ so widely dispersed over this island, yields evi- 
dence of extinct species belonging to genera still represented, but not in 
Britain or in Europe, by living species ; the Hlephas primigenius, Rhinoceros 
tichorhinus, Hippopotamus major, Hyena spelea, are familiar examples. 
Most of the testaceous Mollusks, which lived contemporaneously with these 
extinct quadrupeds in England, belong to species which still exist in this 
island ; indicating, as Mr. Lyell* has justly observed, that the climate was not 
so hot as that of the latitudes to which the Elephant, Rhinoceros and Hip- 
popotamus are now confined. 
The freshwater deposits, as those discovered by Mr. Brown at Clacton in 
Essex, and described by Mr. Lyell at Mundesley and other parts of the 
Norwich coast, which, from the occurrence of a few species of shells distinct 
from any at present known in a living state, are referable to the newest ter- 
tiary epoch, contain similar evidence of extinct species of Mammalia; some 
belonging to genera, as Canis, Ursus, Felis, Putorius, Arvicola, Castor, 
Equus, Bos, Cervus, still represented by European species, and others to 
genera, as Elephas, Rhinoceros, Hippopotamus, Hyena, now confined to the 
warmer parts of Asia and Africa. 
The same association of Mammalian fossils in the ossiferous caverns of 
Great Britain, indicates the period of their introduction to have corresponded 
with that of the deposition of the remains above alluded to in the newer 
pliocene strata; in some of the latter, however, as in the lacustrine ligni- 
ferous beds near Bacton, on the Norfolk coast, we obtain evidence of extinct 
subgenera of Insectivora and Rodentia, as the Paleospalax and Trogontherium. 
When we descend to the older pliocene tertiary formations, as the fluvio- 
marine crag at Whitlingham, Postwick, Thorpe, and Bramerton in Norfolk, 
remains of the Mastodon occur. 
The Eocene tertiary formations reveal more numerous extinct Mammalian 
genera, and more remote than the Mastodon from existing types ; while the 
indications of existing genera, as of the Macacus, and perhaps Didelphys, 
are very scanty, and such as one might have least expected to meet with in 
the latitudes of England. 
The constancy of the association of particular organic remains with parti- 
cular geological strata, is most strikingly illustrated by discovering in the 
Eocene deposits of England the same peculiar extinct Mammalia which had 
been determined by Cuvier’s masterly investigations of the fossil remains from 
the corresponding formations on the Continent. In addition to Lophiodon, 
Paleotherium, Anoplotherium, Dichobunes, and Cheropotamus, only one other 
extinct genus has been discovered in the Eocene strata of Britain, viz. the 
Hyracotherium, and the nearest affinities of this little Pachyderm are to the 
Cheropotamus of the same epoch. 
* Principles of Geology, ed. 1835, vol. i. p. 142. 
