SYSTEMATIC REVISION 37 



of the teeth, so that the presence of canines can not be demonstrated. Those which 

 are visible are on the premaxillary and anterior parts of the maxillary bones. They 

 are small, conic, slightly curved, acute, and absolutely smooth. 



"The muzzle is short and broadly rounded. The narial opening is latero- 

 superior, and is just above the principal convexity where the lores pass into the 

 muzzle. Canthus rostralis rounded oft. Interorbital region wide, convex in section, 

 nearly plane antero-posteriorly, its width a little exceeding the diameter of the orbit. 

 Orbit large and round, its diameter equal to the length of the muzzle in front of it, 

 obliquely measured, and one half the distance from its posterior edge to that of the 

 temporal roof (? squamosal bone). Posterior outline of the skull above truncate, 

 surface slightly convex transversely. 



"The premaxillary spines are short and wide, the nasals are also short and wide. 

 The prefrontals and postfrontals form the superior edge of the orbit excluding the 

 frontals. The intercalaria (or ? pterotics) are very large; at the externoposterior 

 angle is a very small element in contact with the supraoccipital which may be the 

 true intercalare. The supraoccipitals have considerable transverse extent, running 

 out externally in narrow apices. All the bones of the skull are sculptured in honey- 

 comb fashion, the ridges radiating on some of the bones — that is, on the posterior 

 parts of the frontals and parietals and anterior part of the intercalare and squamosal. 

 A groove follows the edge of the orbit and turns inward on the prefrontal bone, 

 forming a rudimental lyra. External surfaces of the mandible grooved below; 

 superior part concealed. 



"Measurements. 



M 



"Width of skull between posterior angles ... 0.018 



Interorbital width . 008 



Axial length of the skull 024 



Axial length from muzzle to between centres of orbits 0096 



Width of muzzle at nares 0095 



Length from orbit to nostril . 00 35 



Depth of skull posteriorly, to mandible OIO 



"The superior part of the posterior region of the inner face of the dentary bone 

 supports a patch of small obtuse teeth, which narrows forwards into the single row 

 on the edge of the ramus." 



Revised description of the genus and species: 



1. Skull low and rounded anteriorly, amphibian in appearance. 



2. Orbits large, located in the anterior haif of the skull. 



3. Teeth more sharply conical. 



4. The teeth are missing in the position of the enlarged cheek tooth of other 



forms so that this character can not be made out. 



5. Teeth in more than one row in the lower jaw; the maxillary series not 



visible. 



6. Basioccipital and basisphenoid not visible. 



7. Supraoccipital plates horizontal in the specimen. 



8. Bones of skull with a fine radiating sculpture. 



9. 10, 11. Not determinable. 



The character of the sculpture, the position of the orbits, the minute size of the 

 pineal foramen (none can be made out with certainty in the specimen), and the 

 presence of a prominent coronoid process on the lower jaw, all indicate that this 



