HYLEOSAURUS. 253 



peculiar functions, attended by compensations adapted to shifting 

 conditions of the instrument, during different stages of its consump- 

 tion. And we must estimate the works of nature by a different 

 standard from that which we apply to the productions of human art, 

 if we can view such examples of mechanical contrivance, united with 

 so much economy of expenditure, and with such anticipated adapta- 

 tions to varying conditions in their application, without feeling a 

 profound conviction that all this adjustment has resulted from design 

 and high inteUigence." — Buckland's Bridgewater Treatise, vol. i, 

 p. 249. 



HYLEOSAURUS. 



104. Dr. Mantell has discovered, in the limestone of the Tilgate 

 forest the remains of a second gigantic reptile generically distinct from 

 the Iguanodon and for which he has proposed the name of Hyleosaurus : 

 of this species he observes " the teeth are unknown ; but in the quarries 

 where the bones of that reptile were discovered, I have found teeth of 

 a very peculiar form, which appear to have belonged to a reptile, and 

 are entirely distinct from those of the Megalosaurus, Iguanodon, 

 Crocodile and Plesiosaurus, whose remains occur in the Tilgate 

 strata." (1) 



One of these teeth, which may be referred with much probability 

 to the Hylaosaurus,{2) is figured of the natural size in PI. 62 a. 

 fig. 8. The fang of the tooth is subcylindrical, subelongate, smooth ; 

 the crown expanded, compressed, slightly incurved, with the narrow 

 sides straight and converging at a slightly acute angle to the apex. 

 In all these teeth which I have seen, these sloping sides show the 

 effects of attrition : the enamel being worn away and the dentine 

 exposed. 



The tooth consists of a body of dentine covered by a thick coating of 

 clear structureless enamel, and surrounding a small central column of 

 true bone, consisting of the ossified remains of thepulp, which presents the 



(1) Wonders of Geology, vol. 1, p. 403. 



C2) They unquestionably do not belong, as has been supposed, to the Keuper genus Cylin- 

 dricodon of Jaeger. 



