566 



THE WONDERS OE GEOLOGY. Lect. V. 



22. Reptiles of the Permian. — The earliest certain in- 

 dications of the existence of reptiles on our globe, have been 

 obtained from the deposits of the Permian system ; for no 

 teeth or bones of any animals of a higher order than fishes, 

 have been discovered in any of the more ancient formations. 

 Impressions of the footsteps of quadrupeds have however re- 

 cently been observed on limestones of the carboniferous epoch 

 in North America ; and during the present year, the skele- 

 ton of a saurian, four feet long, is said to have been found in 

 strata of the same age in Germany.* It is therefore pro- 

 bable, that we shall ere long, obtain proofs that cold-blooded 

 quadrupeds were coeval with the luxuriant flora of the coal. 



In the Zechstein of Thuringia, and in the Dolomitic con- 

 glomerate of Somersetshire, the remains of several genera 

 of large thecodont*)* lizards have been disco \ered. 



Thecodontosaurus and Palceosawus. — These British fos- 

 sils were obtained from Redland, near Bristol, and are pre- 

 served in the museum of that city ; they consist of jaws, 

 teeth, vertebrae, and bones of the extremities, referable to 

 two genera of saurians, named as above by Dr. Riley and 



forment im groupe des plus remarquables par sa faune ichthyologique, 

 Des Chimerides de forme etrange, les Ceratodus, et les Nemacanthes 

 sont nombreux : des Cestraciontes appartenant aux genres Dictcea, 

 Janassa, Acrodus, et Strophodus, et des Hybodontes, sont a cette 

 epoque les representans de l'ordre des Placoides. Parmi les Ganoides 

 on distingue des L6pidoides des genres Platysomus, Gyrolepis, et 

 Palaeoniscus ; des Sauro'ides des genres Acrolepis, Pygopterus, et 

 Saurichthys, des Celacanthes et des Pycnodontes, parmi lesquels les 

 genres Placodus et Colobodus sont surtout caracteristiques pour le 

 Muschelkalk." — Becherches sur les Poissons Fossiles, tome i. p. xxix. 



* Mr. Lyell has shown me a slab of stone from the middle of the 

 coal strata of Pennsylvania, on which there are decided footprints of a 

 quadruped, apparently of the Batrachian order. See "American 

 Journal of Science," vol. ii. new series, p. 25. Footmarks of this kind 

 were first discovered and described by Dr. A. T. King of Greensburg; 

 see Op. cit. vol. i. p. 268. 



t Thecodont ; i. e. having the teeth implanted in distinct sockets, 

 like the crocodile. 



