292 PALAEONTOLOGY. 



combined the power of the knife and saw ; whilst the apex, 

 in making the first incision, acted like the two-edged point of 

 a sabre. The backward curvature of the full-grown teeth 

 enabled them to retain, like barbs, the prey which they had 

 penetrated. In these adaptations we see contrivances which 

 human ingenuity has also adopted in the preparation of 

 various instruments of art."* 



The oldest known beds from which any remains of Megalo- 

 saurus have been obtained are at the lower oolites at Selsby 

 Hill, and Chipping-Norton, Gloucestershire. Abundant and 

 characteristic remains occur in the Stonesfield slate, Oxford- 

 shire. Teeth of this genus have been found in the Corn brash 

 and Bath oolite ; both teeth and bones are common in the 

 Wealden strata and Purbeck limestone. Some of these fossils 

 indicate a reptile of at least 30 feet in length. 



Genus Hylaeosaurus, Mtll. — Eemains of the Dinosaurian 

 so called have hitherto been found only in Wealden strata, as 

 at Tilgate, Bolney, and Battle. The most instructive evidence 



Fig. 99. 

 Hylceosaurus (Wealden). 



is that which was exposed by the quarrymen of the Wealden 

 stone at Tilgate, and was obtained and described by Mantell 



* Buckland, " BridgeAvater Treatise, p. 236. 



