148 Transactions of the Society. 



extinct animals for the Crystal Palace Company at Sydenham, 

 then in its palmy days. Among these restorations may still he 

 seen the Iguanodon, represented as a pentaaaetyle four-footed beast, 

 the fore and hind limbs being of equal length. From the remark- 

 able discoveries made of late years in the Wealden deposits at 

 Bernissart in Belgium, we now know the true character of the 

 entire skeleton of the Iguanodon, a reproduction of the Brussels 

 Museum skeleton being set up in the Natural History Museum in 

 Cromwell Eoad. 



The proportion between the fore and hind limbs is truly re- 

 markable ; the tail was of very great length ; the hind feet were 

 provided with three toes, and closely resemble in their digits the 

 foot of ordinary birds ; the fore limbs are very much shorter than 

 the hind limbs, and have the full complement of five digits. In an 

 erect position, the animal would measure 15 ft. in height, and about 

 twice that in length ; the only defensive armour consisted of a 

 strong spine on the thumb of each hand, covered in life by a horny 

 sheath ; the cheek teeth, which are very numerous in the sides of 

 the jaw, were — by the trituration of their food (which was of a 

 vegetable nature) — worn fiat on their tops, like the molar teeth in 

 horses. Instead of front teeth, there was a horny covering to the 

 jaws above and below, resembling the beak in the Tortoise or Turtle, 

 by means of which they cropped their food. 



Remains of the carnivorous form of Dinosaur, the Mcgalosaurus, 

 are only imperfectly preserved to us, but from its teeth, limbs, and 

 vertebra we know that it was predaceous in habit, its teeth being 

 adapted for cutting and tearing flesh, not vegetable food ; the feet 

 and hands were armed with sharp claws, like those of carnivorous 

 mammals of the present day. In this group of reptiles, which 

 formerly occupied nearly the whole terrestrial field in the Secondary 

 period, we find the same arrangement as among existing mammals, 

 that is to say, many and very numerous forms of Herbivora, 

 mostly slow-moving, heavy beasts, and a few types of very active 

 and formidable Carnivora, whose business it was to keep down the 

 excessive number of the Herbivora. 



Pterosauma, the flying Lizards, form a remarkable extinct 

 order of Winged Reptiles only met with in the Secondary rocks. 

 These animals had the centra of the vertebrae hollow in front ; they 

 possessed a broad sternum, or " breast bone," with a median ridge 

 or keel, similar to that of birds ; the jaws were usually armed with 

 teeth fixed in sockets. The fore limbs had a short humerus, a long 

 radius and ulna, and one of the fingers of the hand was enormously 

 elongated to give support to the wing-membrane (patagium), which 

 was attached to the sides of the body, the arm, the thumb, and the 

 long finger, and also to the hind limb and tail. The other fingers 

 of the hand were free, and furnished with claws. The wing- 

 membrane appears to have resembled that of the Bat, being desti- 



