xm. AGE OF REPTILES. 391 



in their natural apposition, in the clay exposed in the Great 

 Western Railway near Swindon. No other part of the animal 

 having come under our inspection, it is only on the evidence of 

 these bones that the species can be recognized. 



But this evidence is very clear. Each of the three bones is 

 identified with specimens from Stonesfield and Enstone (Enslow ?) 

 in respect of the distal extremities, and the whole bone can be 

 compared in the case of the middle metatarsal. Neither along the 

 external or internal bones are such appearances to be seen as to 

 indicate any other than the three toes, which also are the only 

 ones recognized among the Stonesfield fossils. (See Diagram 

 LXVIII. p. 215.) 



We have now reached the point in the scale of geological time 

 when, from this part of the earth's surface, the great forms of 

 reptilian life appear to have departed. Elsewhere the ' age of rep- 

 tiles ' was indeed extended to more recent dates, in the wealden of 

 Sussex, and the cretaceous strata of Kent and Cambridge; but 

 there also the series came to an end. Ichthyosaur and plesiosaur, 

 iguanodon and pterodactyl, vanished with many other forms of 

 ancient life ; and true crocodiles swam in the estuary of the 

 Thames, over the remains of teleosaurs and steneosaurs, buried 

 ' fathoms deep ' in strata of the mesozoic sea. 



In the cliffs of Kimmeridge, Colonel Mansel has found, and 

 Mr. Hulke is examining, animals allied to the pleiosaurian, plesio- 

 saurian, and steneosaurian fossils here noticed. In particular a 

 gavialian crocodile approaching the type here called steneosaurus 6 . 

 These researches will furnish the means of a most interesting com- 

 parison of the fossil reptiles of one zone of life in two most pro- 

 ductive localities. 



e Geol. Proc. 1869. 



