576 



THE WONDERS OF GEOLOGY. Lect. V 



nious length of the neck, and other osteological peculiarities.* 

 The neck, which in most animals is composed of five verte- 

 brae, and in the extreme recent example, the Swan, does not 

 exceed twenty-four, consists of from twenty to forty ; and 

 its length is equal to that of the entire body and tail. This 

 reptile combines in its structure the head of a lizard, 

 with teeth implanted in sockets like the crocodile ; a neck 

 resembling the body of a serpent ; a trunk and tail of the 

 proportions of those of a quadruped ; with paddles like the 

 turtle. The vertebras are longer and less concave than 

 in the Ichthyosaurus, and the ribs, being connected by trans- 

 verse abdominal processes, present a close analogy to those 

 of the Chameleon. 



The collection of Mr. Hawkins, now in the British 

 Museum, contains a skeleton eleven feet long, and so nearly 

 perfect, that the entire form of the original creature may be 

 completely restored. Mr. Conybeare compares the Plesio- 

 saurus to a turtle stripped of its shell, and thinks it probable, 

 from its long neck presenting considerable impediment to 

 rapid progress in the water, that it frequented the coast, and 

 lurked among the weeds in shallow water. As it is evident 

 that it must have required frequent respiration, it probably 

 swam on or near the surface, and darted down upon the 

 small fishes on which it preyed. 



Ichthyosauri and Plesiosauri have been found throughout 

 the secondary strata, from the Lias to the Chalk inclusive ; 

 Lyme Regis is the most celebrated locality in England, 

 but the remains of numerous species of both genera have 

 been discovered in many places in this country, and on the 

 Continent, in the Oolite and Lias. The British species of 

 the Enalio-sauri known and described by Professor Owen, 

 amount to ten or twelve of the Ichthyosaurus, and nearly 

 twenty of the Plesiosaurus.f Their remains have been 



* In the sternum of the Plesiosaurus the ooracoid bones have their 

 greatest development. 



f British Assoc. Reports for 1839, p. 126. 



