18 
in the London area, the Aldermanic sentiment having originated 
from the former luxuriance of the animal, or that the present 
delicacy may be an ideal survival of its former residence here. 
The crocodiles and turtles indicate some shore upon which they 
deposited their eggs, while the soft turtle as at present, on the 
banks of the Nile, probably performed the office of keeping in 
check the greater increase of crocodiles by occasionally feasting 
on their eggs. - 
Nor were these the only indications of land conditions ; wading 
birds and birds of prey were present; also forms of ungulate 
mammals, related to the hog and tapir—the Hyracotherium and 
Coryphodon ; while Palwophis, if a land snake, as large as an 
ordinary boa threaded its way through the dense groves of ever- 
greens and succulent plants, the stems and fruits of which, and 
other plants, are found so abundantly at Sheppy, as described 
by Dr. Bowerbank.* Besides the conifere and other trees, we 
find the gourd, custard apple, mallow, and numbers of the fruit of 
a peculiar palm (nipadites), related to the Nipa, which grows in such 
abundance in the Moluccas, Philippines, and India, that its fruits, 
in floating down, almost. obstruct the navigation of the Ganges 
through the Delta, associated with which are cones of Petro- 
philoides, a genus of Proteacer, now so characteristic of the 
Australian continent.t 
Besides these are many species of Leguminose, allied to 
Mimosa and Acacia, and also some Euphorbie, groups now nearly 
confined to tropical forests, and hence is inferred the character of 
the climate in this area at the period in question. 
With the London clay, the Eocene formations, seen in the 
vicinity of Croydon, terminate, and a great hiatus, representing a 
long lapse of time, intervenes between it and the superficial gravel 
here—an imperfection in the geological record, from the want of 
continuity. Suffice to say that vast physical changes took place 
* Fossil Fruits and Seeds of the London Clay, 1840. 
+ There are two brickyards on the north of Sutton, about half a mile from the 
boundary-line, and at Carshalton Gas Works stiff blue clay was found. Eastward of this 
the junction with the Reading Beds is hidden by the gravel of the Wandle. 
In a field on the northern side of the by-road nearly three-quarters of a mile to the 
west of West Croydon Railway Station, I saw (in 1859) a small shallow pit in brown sandy 
clay, probably the lowest part of the London Clay. In the cutting at the station the clay 
is shown beneath the gravel. 
At Croydon the London Clay seems to have been cut back northwards in a hay-like 
form, but the boundary-line is in great part hidden by the thick mass of gravel here. 
The sections at Selhurst however show that there must be a slight upheaval, as else the 
beds below would not have been laid bare. 
At the Selhurst brickyard the bottom part of the formation is shown. The higher 
pits at this place show the London Clay only ; the upper part brown (discoloured by 
oxidation), and with septaria; the lower part a little sandy, bluish-grey brown and 
yellow (ochreous), roughly laminated, and with many crystals of selenite. Lower pits 
show the junction with the underlying Oldhaven Beds. 
_ As the broad extent of country taken up by the London Clay is free from Drift, 
with the exception of the gravel along the valley of the Wandle, &c., and on Kingston 
and ib se Hills, its clayey nature is most marked.—Whitaker, Mem. Geol. Surv., 
vol. iv., p. 282. 
