772 



HISTORICAL GEOLOGY. 



3. Fishes. — Hybodont and Cestraciont sharks of the genera Hyhodus, 

 Acrodus, and Strophodus here first appear : Fig. 361, a tooth of Hyhodus 

 minor Ag., from the Keuper, and Fig. 362, of H. pUcatilis Ag. There were 

 also Ganoids of the genera Saurichthys, Gyrolepis, Amhlypterus, Palceoniscus, 

 Pycnodus, etc. ; and Ceratodus of the Dipnoans. 



4. Amphibians. — The Labyrinthodont, Mastodonsaurus g ig ayiteus, wa.s a 

 scale-covered species ; Fig. 1263 represents its cranium, which was two feet 

 long, and Fig. 1263 a, a tooth three inches long. Several other species of 

 Labyrinthodonts are known from British and European beds. The tracks. 

 Fig. 1264, named Chirotherium (from )(eip, hand, and drjpLov), are supposed to 

 be those of a Labyrinthodont. 



1263 a. 



1263. 



1263-1265. 



1265. 



Amphibians. — Fig-. 1263, Mastodonsaurus giganteus (x j'j) ; 1263 a, tooth of same ; 1261, Chirotheriuni (x ^) ; 

 1265, track of a Turtle ? Figs. 1263, 1263 a, Braun ; 1264, 1265, D'Orbigny. 



5. Reptiles. — The British and other foreign Triassic Reptiles comprise 

 species of Ehynchocephs, Anomodonts, Belodont Crocodilians, Dinosaurs, 



1266. 



Ehynchoceph. — Fig. 1266, Telerpeton Elgineuse. From Mantell. 



Chelonians, and Sea-Saurians. Under the Rhynchocephs, there are the 

 genera : Hyperodapedon of Huxley, species of which occur in the Triassic 



