148 
Geology of Sydney. 
They reveal distinctly the food and the internal organ- 
ism of the Mesozoic saurian. In them have been found 
the scales and bones of smaller animals of their own 
species. The quarries of Lyme Regis, in Dorsetshire, 
England, abound in the remains of the Ichthyosaur. 
(2) The Plesiosaur had the head of a lizard, the 
teeth of a crocodile, a swan-like neck, the trunk 
of a quadruped, the ribs of a chameleon, and tho 
paddles of a whale. Its tail was shorter than that of 
the ichthyosaur, being only sufficient to act as a rudder 
in guiding the body. To compensate this loss and 
assist propulsion, its paddles were much larger and 
more powerful. Its appearance presented a striking- 
contrast to that of its more ponderous foe, the ichthy- 
osaur, whose attacks it could escape by sinking to the 
bottom, while its long neck reached to the surface of 
the water and maintained respiration. 
(3) The Pterodactyle (wing-fingered), in its 
apparent monstrosity surpassed even the two reptiles 
just mentioned. It was so named because the bone of 
one finger was greatly expanded in order to support 
an extended membrane for flying. It was a true 
aerial reptile. Its wings resembled those of bats. Its 
bones were hollow, like those of birds, but it bore no 
feathers, and had a mouth full of teeth. Remains 
have been found indicating a spread of wing of not less 
than sixteen feet ; but, in the usual species of the 
Liassic, did not exceed ten inches in length. Its 
ordinary position was upon its hind feet, walking up- 
