134 



AMPHIBIA 



CLASS II 



Mastodonsaurus, Jaeger (Figs. 204, 206, 226). Largest of all Labyrintho- 

 donts, skull T25 m. long, depressed, and with large orbits behind the 

 middle. External bones sculptured, sensory canals prominent. Premaxillae 

 pierced for the passage of the two greatly enlarged teeth at symphysis of 

 lower jaw. Vomers with a pair of tusks in front of the posterior nares, and 

 another near the hinder margin ; palatines with a 

 single series of large teeth. Dentine excessively 

 complicated. Interclavicle rhomboidal, clavicles 

 triangular, all strongly sculptured. Ischium very 

 large, pubis small, ilium elongated, and articulating 

 with the sacral ribs. Limbs very imperfectly 

 known, and dermal armour not 

 observed. The most perfect re- 

 mains are from the Lettenkohle of 



ang 



Skull of Mastodonsaurus giganteus, Jaeger. A, 

 Orbit ; N, External nares ; X, Openings for the 

 passage of the tusks of lower jaw ; Pmx, Pre- 

 maxilla ; Mx, Maxilla ; Na, Nasal ; La, Lachrymal ; 

 Pfr, Prefrontal ; Fr, Frontal ; Ptf, Postfrontal ; 

 Pa, Parietal ; PtO, Postorbital ; Sq, Squamosal ; 

 SO, Supratemporal ; Ep, Epiotic ; J, Jugal ; Qj, 

 Quadrato-jugal ; ExO, Exoccipital (after E. Fraas). 



Fig. 227. 



Lower jaw of Capito- 

 saurus nasulus, v. 

 Meyer. Trias Bern- 

 burg^ 



Fig. 22S. 



Footprints of Cheirotheriwm 

 barthi, Kaup. Buntsandstein; 

 Hessberg, near Hildberghausen. 

 1/6 (after Owen). 



Gaildorf and Oedendorf in Wiirtemberg. Fragments occur also in the Upper 

 Trias of England and India, and possibly also in the Buntsandstein of Alsace 

 and the Black Forest. 



Labyrinthodon, Owen. Upper Trias ; England. fihyfidosteus, Owen. 

 Karoo Formation ; Orange Free State. Pachygonia, Gonioglyptiis, Huxley. 

 Trias ; East India. 



Footprints. — Stegocephalian footmarks are not uncommon in the Coal 



