EXTINCT AMPHIBIA OF NORTH AMERICA 75. 
show the coarse sculpturing of the larger species of the Microsauria and 
it consists more of radiating grooves than of pits. The skull, as 
restored, is broadly ovate, with the posterior border truncate. The 
muzzle is broad and the nostrils are, apparently, located near the 
anterior margin. The pineal foramen cannot be detected. The 
posterior border of the orbits les near the median transverse line of 
the skull. They are circular and are removed some distance from 
the margin of the cranium. Only the frontal and parietal can be 
Fic. 19.—The cranium of Sauropleura longidentata. Natural size. 
determined with certainty. These are seen to be rather large and 
have the usual relations of those elements. 
The lower jaw is heavy and it is provided with heterodont teeth, 
which were possibly pleurodont, though this cannot be determined 
since the specimen lies on its inner side. Near the anterior end of the 
mandible there is a very long fang-like tooth, longitudinally striated, 
which rises from a broad base and rises to considerable prominence. 
It is slightly recurved. The other teeth are smaller though the next 
