212 MARINE SAURIANS. 
that it may have occasionally visited the shore, 
the resemblance of its extremities to those of 
the Turtle may lead us to conjecture ; its motion 
however must have been very awkward on land ; 
its long neck must have impeded its progress 
through the water ; presenting a striking con- 
trast to the organization which so admirably 
fits the Ichthyosaurus to cut through the waves. 
May it not therefore be concluded (since, in 
addition to these circum.stances, its respiration 
must have required frequent access of air,) that 
it swam upon, or near the surface ; arching 
back its long neck like the swan, and occasion- 
ally darting it down at the fish which happened 
to float within its reach. It may perhaps have 
lurked in shoal water along the coast, concealed 
among the sea-weed, and raising its nostrils to a 
level with the surface from a considerable depth, 
may have found a secure retreat from the as- 
saults of dangerous enemies; while the length 
and flexibility of its neck may have compen- 
sated for the want of strength in its jaws, and 
its incapacity for swift motion through the water, 
by the suddenness and agility of the attack 
which they enabled it to make on every animal 
fitted for its prey, which came within its reach." 
— Geol. Trans, n. s. vol. i. part ii. p. 388. 
We began our account of the Plesiosaurus 
with quoting the high authority of Cuvier, for 
considering it as one of the most anomalous and 
monstrous productions of the ancient systems of 
