290 
FOSSIL REPTILES 
in the Ossemens Fossiles — and the volume expressly 
dedicated to the fossils of Tilgate Forest, have 
subsequently been published, and comprehend all 
the contributions hitherto made towards the his- 
tory of these extraordinary remains. I propose to 
offer a general view of what is already known on 
this subject, incorporating therewith the results 
of subsequent discoveries ; to notice in a cur- 
sory manner the facts previously established, and 
dwell witli requisite detail on the important ad- 
ditions to our anatomical knowledge of these extinct 
oviparous quadrupeds, which recent investigations 
have brought to light. 
The geological characters of the country in 
which these remains occur are so well known, that 
it is only necessary to observe, that with the ex- 
ception of alluvial deposits, and here and there 
insulated portions of the tertiary strata, the district 
is composed of two formations, namely, the Chalk, 
and the Wealden ; the strata of the former con- 
taining marine exuvim only, and having evidently 
been deposited in the tranquil depths of an ocean ; 
while those of the latter teem with the remains of 
land and freshwater animals and vegetables, and 
are manifestly the sedimentary deposits which, in 
the earlier ages of our planet, constituted the delta 
of an immense river. 
The mutilations which the carcases of the rep- 
tiles appear to have sustained, before they were 
imbedded and preserved in the silt and other sedi- 
ments of the waters, and the promiscuous inter- 
mixture of tlie osseous fragments of various species, 
occasion the attempt to reconstruct their skeletons 
to be a work of considerable difficulty : and as I 
