198 Royal Institution. 
forests in which these creatures live. Then, to prevent mischievous 
effects from the decomposition of vegetable matter in countries where 
it is so luxuriant, decaying plants furnish food to Termites and other 
insects, which, in their turn, support a peculiar genus of quadrupeds, 
the Myrmecophaga (or ant-eaters). In closing this part of his sub- 
ject, the Professor noticed the armour-like, osseous skin of the arma- 
dillos, which live at the foot of trees, and are, therefore, extremely 
liable to blows from falling boughs, &c. 
In other parts of the world, where vegetation is abundant, the 
quadrupeds related with it are generically distinct from those of 
South America. This adaptation of species to locality having im- 
pressed itself strongly on his mind in regard to the present globe, the 
Professor stated, that he early applied himself to inquire whether— 
4. The extinct species of mammals were localized like the present races. 
—For this purpose he formed a full and correct catalogue of the fos- 
sil remains of mammals in our island. He then gave a rapid sketch 
of the successive races of the extinct mammals, as they have been 
traced by the fossils in the ascending series of strata in England and 
Scotland. The first examples of this class are found in the lime- 
stone slate of Stonesfield, at the base of the middle oolite. These 
fossils were remains of small insectivorous, and probably marsupial, 
quadrupeds, associated with remains of beetles, vegetable fossils, 
shells, and fishes allied to the Cestracion. These recall many of the 
characteristic features of actual organic life in Australia. During 
the long period which followed the formation of the Stonesfield slate, 
and which has permitted the subsequent, successive, and gradual accu- 
mulation of enormous masses of sedimentary rocks, viz. great oolite, 
cornbrash, forest marble, Oxford clay, calcareous grit, coral rags, 
Kimmeridge clay, Portland stone, Wealden, gault, greensand, chalk, © 
no trace of a mammalian fossil has been found. In England we first 
obtain evidence of that class of animals in the debris of some conti- 
nent, poured out by vast rivers upon the surface of the chalk, form- 
ing masses 1000 feet in depth—the Plastic and London clays. Here 
are remains of great Tapiroids, as Lophiodon and Coryphodon, and 
smaller pachyderms, like peccaries—Hyracotherium. Here, with 
boa constrictors, are turtles, sharks, fossil palms, and other forms of 
tropical vegetation. At the same period there were alternating fresh- 
water and marine deposits in continental Europe, filling up a vast 
excavation of chalk, called the Paris basin, and forming the founda- 
tions on which that city is built, analogous to the clays on which 
London stands. Here Cuvier first discovered and described the Ano- 
plotherium, Paleotherium and Cheropotamus. 
The Professor then briefly noticed the existence of similar calca- 
reous freshwater and marine deposits in the Isle of Wight, and ad- 
verted to the discoveries of Mr. Allen and Mr. Pratt. It was, how- 
ever, remarked, that little is gained by comparison of eocene and 
existing mammals, excepting so far as these indicate a great change 
in the distribution of earth and sea, and an accompanying alteration 
of climate. With the last layer of eocene deposits, we lose in En- 
gland every trace of the peculiar mammals of that period. A vast 
series of geological operations took place, from which the miocene 
