Atitediluvian Zoology, 365 



92 



^*™^i^ 



Restoration of the Plesiosaurus dolichodelrus. Geol. Trans., vol. i. pi. xlix. 2d series, fig. 6. 



those of turtles, and in other respects its proportions present 

 some approach to those animals. * 



The Ichthyosaurus {Jigs, 93. and 94.) recedes from the form 



Sketch of Ichthyosaftrus, discovered in the Whitby alum shale, and figured by Messrs. Young 

 and Bird, Geol. of Yorkshire. 



of the lizard family, and in the structure of its vertebrae it 

 approaches that of fishes. It has forty-one cervical and dorsal 



* From Mr. Coneybeare's interesting anatomical description of the Ple- 

 siosaurus we learn that this animal had from thirty-five to forty-one joints 

 in the neck, which is about seven times the number possessed- by qua- 

 drupeds and Mammalia ; five times that by reptiles ; three times that by 

 birds ; and twice, at least, that by the Ichthyosaurus. 



With reference to the supposed habits of this animal, we cannot forbear 

 quoting this accomplished naturalist ; — " That it was aquatic, is evident 

 from the form of its paddles ', that it was marine, is almost equally so, from 

 the remains with which it is universally associated ; that it may have occa- 

 sionally 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 contrast to the organisation which 

 so admirably fits the Ichthyosaurus to cut through the ,waves. May it not 

 therefore be concluded (since, in addition to these circumstances, 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 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 assaults of 

 dangerous enemies ; while the length and flexibility of its neck may have 

 compensated 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 extensive sweep." 



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