104 Proceedings. 



the i^laiies in wliicli these shells lie. Fish, too, of various 

 kinds disported themselves in the waters, these being of the 

 orders known as Ganoid and Placoid, which include fishes 

 covered by hard bony plates and scales, instead of the horny 

 membranous scales siich as we see in the common fishes of 

 our rivers. 



But the most interesting animals were the Eeptiles, not 

 only by reason of their bulk, but from the peculiarity of their 

 anatomy ; and prominent among these was the Iguanodon, 

 whose remains were first found in a pit in Tilgate Forest. 

 This reptile was of prodigious size, some specimens attaining 

 a length of seventy feet, and possessing, as might be expected, 

 a skeleton massive in proportion. But, like most colossal 

 animals, it was probably of a most inoffensive disposition, 

 and a strict vegetarian. But what I wanted particularly to 

 mention was its affinities with another class of Vertebrates, 

 the Birds. 



The EeptUes and Birds are grouped together under one 

 section, the " Sauropsida," or animals having a Lizard-like 

 appearance, for these two classes have many characters in 

 common ; not that we can at present trace a perfect gradation 

 from one class to the other, but among the Reptiles occur 

 forms aberrant from the normal type, which possess many 

 bird-like characteristics ; and in the Birds we also find 

 aberrant forms which tend to merge towards the Eeptiles. 

 It is with regard to the first of these cases, the bird-like 

 reptile, that I wish to make a few observations ; the other 

 case, the reptile-like bird, I shall treat of presently. 



The group of Eeptiles to which the Iguanodon belongs is 

 that of the Deinosauria (signifying " terrible lizards"), a name 

 which, while it does justice to some of the members composing 

 it who were of carnivorous habits, belies the character of 

 others — such as our present subject, the Iguanodon. 



A characteristic of the great majority of the birds is 

 the possession of what we call pneumatic bones, that 

 is, their large bones are hollow, and caj)able of being filled 

 with air, as they are indirectly connected with the lungs. 

 Most of the Deinosauria possess hollow limb-bones, though 



