3S4 



VERTEBUATA. 



^^^ 



THE MEGALOSAUEUS AND PTERODACTTLES. 



Tlie HylcBOsaurus was another enormous reptile, wliose remains were found in the wealden* 

 of Tilirate Forest. This animal appears to have combined some of the features both of the croco- 

 dile and of the lizard. It was covered with thick scales, and along the back was a row of 

 long conical bones or spines, resembling the crests we have described as belonging to the Iguanas 

 and Agaraas. This animal is supposed to have been a terrestrial, herbivorous reptile, between 

 twenty and thirty feet in length. Altogether it must have been of the most extraordinary rep- 

 tilian organization. 



The Mer/alosaurus was another gigantic lizard, whose remains have been found in the same 

 localities as the preceding. From the teeth, of which numerous specimens have been discovered, 

 and which had a conical, saber-hke form, it is inferred that the animal was carnivorous. It was 

 probably twenty-five to thirty feet long. 



The Plesiosatirus we have already described (page 8, vol.1.); of the Ichthyosmirus there were 

 many species. "Tliese," savs Mantell, "had the beak of a porpoise, the teeth of a crocodile, the 

 head and sternum of a lizard, the paddles of a cetacea, and the vertebra? of a fish." Some of the 

 species were of the size of young whales. The bones forming the sternum or chest resemble 

 those of the omithorhynchus ; the paddles are four, and are like those of the turtles. In some 

 species the bones of the fore-paddles are one hundred in number. The general form was like that 

 <")f the grampus. Tlie skin was destitute of scales. It was evidently carnivorous and aquatic. 



* WeaMen. is a term used by English geologists in application to the Vipperrnost series of the strata included in 

 what is called the Oolitic system, that is, the rocks of the secondary formation, of which the Bath stone and Portland 

 stone of England are examples. The term u-eaMeii was adopted from the fact that the formation was first observed 

 in the weolds, that is, woods, of Sussex and Kent, in England. The Tilgate Forests are a part of this region. The 

 whole consists of limestone, conglomerate, sandstone, and clay, abounding in the remains of fresh-water and land 

 animals. These are supposed to have been deposited in an estuary or arm of the sea, which once covered this part 

 of England. 



