360 — Geological Age of Reptiles. 
bones are associated, belong also to a very different order of things 
from that in which the modern oviparous quadrupeds are placed; 
and we are compelled to conclude that the condition of the earth, at 
the period when it was peopled by reptiles, must have been wholly 
different from its present state, and that it probably was then unfit for 
the habitation of animals of a more perfect organization. It is, more- 
over, interesting to remark, that some of these ancient and lost races 
are, as it were, the types of the existing orders and genera; and that 
in the pigmy Monitor and Iguana of modern times, we perceive stri- 
king resemblances to the colossal Megalosaurus and Iguanodon of 
the ancient world. 
It is also worthy of observation, that, as in the present epoch the 
herbivorous quadrupeds are those of the greatest magnitude, so at 
the period when reptiles were the principal inhabitants of our planet, 
the herbivorous were those of the most gigantic proportions. The 
geological period when the existence of reptiles commenced must 
according to the present state of our knowledge, be placed immedi- 
ately after the formation of the coal measures; the remains of Moni- 
tors having been found in the bituminous slate of Thuringia; and 
those of a crocodile in the gypseous red sandstone of England: but 
it is not till we arrive at the Lias that the remains of reptiles occur 
in any considerable quantity. At that period the earth must have 
teemed with oviparous quadrupeds; and the enaliosaurt, oF those 
which inhabited the sea, appear to have been equally numerous with 
those of the land and rivers. The prodigious quantity of the remains 
of these animals which has, within a comparatively short period, been 
found in England alone, is truly astonishing ; and if to these we add 
the immense numbers that have been discovered in France, Ger- 
many, &c., and reflect that for one individual found in a fossil state, 
thousands must have been devoured or decomposed ; and that even 
of those that are fossilized, the number that comes under the notice 
of the naturalist must be trifling compared with the quantities unob- 
served or destroyed by the laborers, we shall have a faint idea of the 
myriads of “creeping things” which inhabited the ancient world. 
In England, the lias contains more especially the remains of two 
extinct marine genera, the Ichthyosaurus, (fish-like lizard,) and Ple- 
siosaurus, (animal resembling a lizard,) whose osteology is most 
traordinary, combining characters observable in the cetacea, fishes, 
and saurians, but yet decidedly belonging to the order of Re 
The Ichthyosaurus, of which several species have been discovere@, 
