THE LIVING WORLD. 
161 
them to both discover their prey at great distances, and to remove it during the 
night to the obscurest depths of the sea. The skulls of the ichthyosauri have 
been discovered whose orbital cavities measured from ten to twelve inches in 
diameter. In the largest species the jaws, armed with sharp teeth, yawned 
for a width of nearly seven feet. The voracity of these animals exposed them 
to the frequent loss of their teeth; but these, as is the case with the crocodile, 
were quickly replaced. 
“ As for the plesiosaurus , the small dimensions of its head, and its thin, 
elongated neck, would seem to indicate that its appetite resembled that of our 
huge serpents.It is probable that this strange creature, whose extraor¬ 
dinary long neck would prevent it from moving rapidly through the water, 
swam upon the surface, or kept close to the shore in shallow water, where, 
concealed among the algae (sea-weed), it might both ensnare its prey and 
hide itself from 
the piercing 
gaze of the 
ich thyosauri, 
its most for¬ 
midable ene¬ 
my.” 
Buckland, 
the great nat¬ 
uralist, who has 
done so much 
for science, 
while pursuing 
his researches 
in West Eng¬ 
land discovered 
the remains of 
a marine croco- skeeeton of the megatherium. 
dile, to which 
he gave the name of megalosaurus (great lizard). This animal is the most 
remarkable of any that is known to have existed. Its form was somewhat like 
a crocodile, but more nearly resembling the Nile monitor, its teeth being 
almost identical in appearance to those of the monitor, but it was so very large, in 
proportion to the crocodile, that it must have exceeded seventy feet in length 
—a lizard large as a whale. Owen, however, thinks it did not exceed thirty feet. 
The celebrated gravel pits near Maestricht have disclosed the bones of 
creatures scarcely less wonderful, among others being- those of a lizard but little 
inferior to the megalosaurus. This gigantic species was called the mesosaurus 
(monitor lizard) which to a gigantic size of twenty-five feet in length was added 
a dreadful armament of immense teeth, arranged in rows like those of the shark. 
Dr. Mantell, another enthusiastic palaeontologist, discovered the remains of 
an animal which evidently belongs to the same family as the megalosaurus , 
but its material differences entitle it to the distinct name which has been given 
to it, viz., iguanodon (a name given to indicate its resemblance to the iguana). 
It was an herbivorous lizard, and its teeth and toes particularly so closely 
resembled the iguana, that hence the name. Its stature was about twenty- 
ii 
