22 PRESIDENT'S ADDRESS. 



of wings from 18 to 25 feet, they were toothless as the name 

 suggests. A splendid cast of Pteranodon leviceps is exhibited on 

 the eastern wall of the Reptile Gallery of the Natural History 

 Museum, Cromwell Road. The wings are eighteen feet across, 

 the fore-limbs (wings) are enormous, and a striking comparison 

 to the hind. Several of the vertebrae are anchylosed to act as a 

 sacrum to the pectoral-arch (like the sacrum in the pelvic-arch) 

 for the support of the powerful wings. The skull is over three 

 feet long. So diminutive are its lower extremities that they seem 

 to have depended on their flying powers for progression almost 

 entirely. The abundance of their remains in the Kansas Beds 

 shews that these great bird-billed Pterosaurs frequented the 

 borders of the Cretaceous seas in search of food. There is little 

 known of the ancestral history of the Pterosauria ; their remains 

 have been found as far back as the Trias, and they became 

 extinct at the end of the Mesozoic Age. 



Lepidosauria comprises the three Orders Lacertilia, Pythono- 

 morpha, and Ophidia. Of these, Lacertilia includes all Reptiles 

 commonly known as Lizards, also the Blind worm Anguis fragilis, 

 which is not a Snake, as its serpentine form leads many to 

 suppose. As a general rule the exo-skeleton of the Lizard 

 consists of horny-scales. The vertebrae are procoelous (cupped 

 in front) rarely on both faces. The teeth are not lodged in 

 distinct sockets, but anchylosed with the jaw bone. In some 

 extinct types however they are in distinct sockets. Their earliest 

 authentic remains date only as far back as the Purbeck and 

 Lower Cretaceous Age. The typical American genus, Iguana, 

 is found in the Oligocene phosphorite beds of Central France, 

 and at Hordwell, Hampshire. 



Varanidae, The Monitor, ranges over the greater part of Africa, 

 the East Indies, and Australia ; it measures six feet and more in 

 length. The Common Monitor of the Nile M. niloticus is found 

 in the vicinity of all the principal streams of tropical Africa. 

 The huge Varanus prisons of the Pleistocene Beds of Australia 

 exceeded twelve feet in length. .Dr. Gunther estimates the number 

 of known species of Lizards to be 700, the larger portion of 



