DINOSAURS. 



membrane of which was attached to the side of the body and supported 

 by the elongated outermost digit, or finger (fig. 2). They are further 

 characterised by the fixed quadrate-bone and the double temporal 

 arches of the bird-like skull. The teeth, when present, are conical 

 and implanted in distinct sockets confined to the margins of the jaws. 



Restoration of a Long-tailed Pterodactyle (RhamjpJiorhynchus phyllurus) , from 

 the Upper Jurassic Lithographic Stone of Bavaria ; one-seventh nat. size. 



There are only four digits in the fore-limb, but five in the hind-one. 

 Many of the bones are hollow. The tail is of variable length ; in 

 the long-tailed Rhamphorhynchus (38) it terminated in a racket- 

 shaped membranous expansion. In Pterodactylus, Rhamphorhyn- 

 chus (36), and Scaphognathus (36 and 37) teeth are present, but they 

 are wanting in Pteranodon of the Cretaceous, some of the species of 

 which had a wing-spread of twenty feet. In spite of certain resem- 

 blances, Pterodactyles have no affinity to Birds, as is shown by the 

 difference in the structure of the wing (figs. 2 and 3). 



Order II.— DINOSAURIA (extinct). 

 (Case 4 and middle of gallery.) 



The members of this order, which includes the largest of all 

 known land animals, are confined (in the main, at least) to the 

 Mesozoic, or Secondary, period of geological history, and thus ceased 

 to exist many thousands of years before man made his appearance 

 on the globe. In most characters Dinosaurs are closely allied to 

 Crocodiles, with the typical forms of which they agree in the fixed 

 quadrate-bone and the double temporal arches of the skull, the 

 restriction of the teeth, which may be implanted in distinct sockets, 



