FOSSILS OF THE WHITE CHALK. 
297 
Fig. 260. in leading us to conclude that the white chalk 
was the product of an open sea of considera¬ 
ble depth. 
The existence of turtles and oviparous sau¬ 
rian s, and of a Pterodactyl or winged lizard, 
found in the white chalk of Maidstone, im- 
plies, no doubt, some neighboring land; but 
* Lo\yer white chalk! a few Small islets in mid-ocean, like Ascen- 
Maidstone. formerly so much frequented by mi¬ 
gratory droves of turtle, might perhaps have afforded the 
required retreat 261 . 
where these crea¬ 
tures laid their 
eggs in the sand, 
or from which the 
flying species may 
have been blown 
out to sea. Of the 
vegetation of such 
islands we have 
scarcely any indi¬ 
cation, but it con¬ 
sisted partly of cy- 
cadaceous plants; 
for a fragment of 
one of these was 
found by Capt. Ib- Cestradon PhUUiypi; recent. Port Jackson. Buckland, 
betson in the Chalk _ Bridgewater Treatise, pi. 2T. <i. 
Marl of the Isle of Wight, and is referred by A. Brongniart 
to Glathraria Lyellii^ Mantell, a species common to the 
antecedent Wealden period. The fossil plants, however, 
of beds corresponding in age to the white chalk at Aix- 
la-Chapelle, presently to be described, like the sandy beds of 
Saxony, before alluded to (p. 293), afford such evidence of 
land as to prove how vague must be any efforts of ours to 
restore the geography of that period. 
The Pterodactyl of the Kentish chalk, above alluded to, 
was of gigantic dimensions, measuring 16 feet 6 inches from 
tip to tip of its outstretched wings. Some of its elongated 
bones were at first mistaken by able anatomists for those of 
birds; of which class no osseous remains have as yet been 
derived from the white chalk, although they have been found 
(as will be S'een at page 299) in the Chloride sand. 
The collector of fossils from the white chalk was former¬ 
ly puzzled by meeting with certain bodies which they call 
larch-cones, which were afterwards recognized by Dr. Buck- 
13 * 
