126 CLASSIFICATION OP AMPHIBIANS. 



themselves, it follows that this group must be aberrant, 

 and of equal rank with the Emydosaures, or crocodiles, 

 and the chelonians, or tortoises. We have aheady seen 

 that these latter, that is, the crocodiles and the chelo- 

 nians, are also aberrant, since the first leads to the class 

 Amphibia, and the latter to the Cephalopoda or cuttle- 

 fish. It follows, therefore, that as one of the great 

 divisions of reptiles should lead to fish, the Enalosawi, 

 by the above theory, precisely occupy that station in the 

 circle of Reptilia, which should blend into that class of 

 animals. Hence we have the body of a reptile with the 

 fins of a fish; hence the pecuHarly expressive name of 

 Ichthyosaurus, or fish-hzard ; and hence the strong im- 

 pression on the judgment of sir Everard Home for near 

 two years after the first discovery of this fossil, that it 

 belonged to some gigantic fish aUied to the sharks. 

 Now all these circumstances tend to show, that not only 

 in general appearance, but in anatomical detail, the 

 structure of these aquatic reptUes much more resembled 

 fish than they did crocodiles. Both sir E. Home and 

 M. Cuvier have proved this affinity by a series of the 

 most minute and valuable comparisons, although the 

 latter is not very precise on the inferences to be drawn 

 from these researches. Sir Everard observed that the 

 shoulder, in the first specimen he examined, exhibited 

 some relation to that of the crocodile; but the position 

 of the nostrUs, the circle of osseous pieces surrounding 

 the sclerotic tunic of the eye, and more particularly the 

 structure of the vertebrae, induced that able comparative 

 anatomist to decide on the approximation of the Ichthyo- 

 saurus to fishes. M. Cuvier, indeed, seems to infer that 

 this wonderful reptUe, upon the whole, was more allied 

 to the saurians, yet he is obliged to confess that " as 

 much as the Ichthyosaurus resembles the lizards in the 

 form of its osseous head, so much does it differ from 

 them in the conformation of its vertebrae, and in this 

 respect it decidedly approaches the fishes and Cetacecs, 

 as," continues our author, '' sir Everard has well re- 

 marked." The joint opinion, therefore, of two such 



