ORDER I 



STEGOCEPHALIA 



127 



Kilkenny, Ireland. Lower Permian ; Niirschan, Bohemia. U. scalaris, 

 Fritsch. 



Acanthostonia, Credner (Fig. 213). Skull 25-35 cm. long, sharply para- 

 bolic in outline, externally pitted. Orbits relatively small, rounded, placed 



Fig. 211. 



Keraterpeion erassum, Fritsch. Lower Permian ; Niirschau, 

 Bohemia. Restored. 1/1 (after Fritsch). 



Fig. 212. 



Urocordyhis wandetfordii , Huxley. 



Coal Measures; Kilkenny. Ireland. 

 Caudal vertebrae, V] (after Huxley). 





Qui! 



Fig. 213. 



Palatal aspect of skull of Acanthostonia 

 vorax, restored. Vi (after Credner). .1, 

 Orbit; N, Internal nares ; Pmx, Pre- 

 maxilla ; Mx, .Maxilla; Qui, Quadrato- 

 jugal ; PSph, Parasphenoid ; /'/. Ptery- 

 goid. 



in posterior half of the skull, and with sclerotic ring. All bones of the 

 buccal cavitv set with teeth. Lower Permian ; Saxony. 



Family ±. Aistopodidae. MialL (Aistopoda.) 



Body serpentiform, without either limbs or arches for their support. Vertebrae 

 constricted amphicoelous cylinders. Teeth simple, conical, hollow. l!i l >s slender, 

 with one or two processes. Carboniferous and Permian. 



