58 THE TRIAS AND OOLITE. 



species have been distinguished, was an animal of marine 

 habits and great bulk, (reaching about thirty feet in length,) 

 in which to the form of the fish there were united, in a re- 

 markable way, characters of animals higher in the scale. A 

 body, framed upon a purely piscine vertebral column, con- 

 taining a huge voracious stomach, and terminating in a ver- 

 tically expanded tail, in which respect it also preserved the 

 fish character, was furnished with the head of a crocodile, and 

 four fins approximating to the character of the paddles of the 

 whale, but composed of a greater number of bones, and thus 

 showing an affinity to the fins of fishes. Over all was a skin 

 resembling that of the cetaceous animals. Nor should it be 

 omitted that the sternum or breast-bone presents a structure 

 resembling that of the ornithorhynchus or duck-rat of Aus- 

 tralia. The vast jaws of this animal, having a stretch of seven 

 feet ; its eye resting in a socket eighteen inches in diameter, 

 and defended by an apparatus of bony plates, like that of a 

 bird of prey ; the powerful range of teeth, and the position 

 of the breathing apertures near the extremity of the snout ; 

 all speak to the naturalist of ferocious habits like those of the 

 modern crocodile, to which the ichthyosaur may be considered 

 as a link from the predaceous fish. A curious light has been 

 thrown upon these habits by the pellets voided by the animal, 

 which have been found in great quantities in a fossilized 

 state, and bear the name of coprolites. In these we find 

 fragments not only of fish, but of reptiles, arguing that 

 the animal must have been a destructive creature both to its 

 own class and to that below it. 



The genus next in importance is the Plesiosaurus, so called 

 as being near to the saurian character. This animal was 

 under eighteen feet long, and altogether a feebler creature 

 than the Ichthyosaur, which seems to have made it a prey. 

 Yet it was itself one of the destructive potentates of the early 

 seas. A body, generally fish-like, though framed on vertebrae 

 presenting less concave ends, and which terminated in a short 

 tail, serving only as a rudder, was furnished with a long neck 

 and small head, together with four slender paddles, more 

 cetacean than those of the Ichthyosaur. Moving, like that 



