122 CLASSIFICATION OF AMPHIBIANS. 



and tail each occupying a foot; but detaclied portions of 

 the flat-toothed sort have been founds proving they 

 belonged to individuals which measured from twenty to 

 one and twenty feet long. We have no means of as- 

 certaining the nature of its external skin, whether it 

 was naked as in frogs_, or hard, as in crocodiles. The 

 first conjecture^ however_, seems most probable, as there 

 appears not to have been any external ears, and the skin 

 passed over the tympanic bone, without becoming 

 thinner, — a structure similar to that seen in the cameleon, 

 salamander, and pipa. The remains of Ichthyosauri are 

 more frequent in England than in any other country of 

 Europe : they occur in the oolites, or grey sandstone, 

 and the lias, or blue slate of the older beds (denominated 

 by Cuvier the formation of Jura). The quarries of 

 Lyme and Charmouth, in Dorsetshire, have produced 

 the most perfect specunens : but they likewise occur in 

 Warwickshire, and many other parts of the kingdom. 



(123.) The Plesiosaurus, or serpent-lizard, is even 

 a more wonderful reptile than the last. Without enter- 





38 









-^ "-^ '-^ ITS V~N 



ing into the minute details of its anatomy, the above cut 

 (^fig. 38.) will be sufficient to give the reader a good idea of 

 its shape. Let him, then, suppose a lizard-shaped animal, 

 full ten feet long, with an enormously long neck, like 

 the body of a serpent, occupying near half the total 

 length, and surmounted by a head disproportionably 

 smaU to the bulk of the body ; four enormous paddles 

 or fins occupy the place of feet, while the tail is short, 

 stout, and pointed. Such is the extraordinary reptile 

 discovered in the year 1824, by an accomplished and 



