LYSOROPHUS, A PERMIAN URODELE. 



233 



these pairs also seems to have a thickened and recurved posterior 

 extremity. The mandibles are rather stout, extending a short 

 distance back of the cotylus, expanded and flattened, somewhat 

 spout-Hke in front. Each bears about twelve, conical, simple teeth 

 on the anterior, somewhat concave margin, which is about two 



Fig. 2. Lysorophus tricarinatus, skull from above, enlarged five diameters. «, 

 nasal ; f, frontal ; pf, prefrontal ; /, parietal ; so, supraoccipital ; eo, epiotic ; pa, 

 proatlas. 



fifths the length of the mandible ; the teeth are directed some- 

 what obliquely outward. 



The sides of the skull are in a nearly vertical plane, directed 



