54 



GEOLOGY. 



the sheaths of the claws. One foot also shows the hind-claw of the 

 bird (not positively known before) still attached to the foot. 



Three nearly entire skeletons of Dinornis are placed in cases, one 

 (Fig. 22) in front of the window on the East side, and two on the 

 South side against the wall of this Room, the tallest being over 10 

 feet in height and the smallest only 3 feet. 



Gallery " D." Class 3.— REPTILIA. 



Quitting the S.E. Gallery, near its eastern end, we pass by a passage 

 into Gallery " D," which runs parallel with the former on its northern 

 side. 



This Gallery is devoted to the exhibition of the remains of fossil 

 Reptilia, a class which includes the Tortoises and Turtles, Snakes, 

 Lizards, Crocodiles, and a large number of extinct forms, tbe exact 

 zoological position of many of which we can only judge by analogy. 

 Like the Mammalia, the Reptilian class lived both on land and in the 

 water ; some being evidently fitted for terrestrial locomotion by 

 their well-developed legs ; others, as shown by their paddle-shaped 



Fig. 24. —Restoration of Rhamphorhynchus pkyllurus (Marsh), one-seventh natural size, 

 from the Lithographic Stone, Solenhofen, Bavaria. 



limb-bones, must have passed their entire existence in the water, j 

 One group, now extinct, possessed, like the Bats and the Birds, the j 

 power of flight. 



In Wall-case 1, and in Table-cases 1 and 2, are placed the fossil 

 remains of this last-named group of " Flying Lizards " or Pterodac- 

 tyles. 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-limb had a short humerus, a long 



r * A remarkable genus of Pterodactyles has lately been discovered and described by ; 

 Prof. Marsh in North America, and named Pteranodon ; they were wholly destitute 

 of teeth, and probably had their jaws encased in horny beaks like birds. 



