312 SAMUEL W. WILL1ST0N 



thought that I found in two specimens a suture separating the 

 posterior part of the squamosal, and recognized it as the "epiotic," 

 following Cope. A skull acquired very soon thereafter showed 

 clearly that there was no such suture, and that the ascription of a 

 tabular was an error, as recorded by Branson {op. cit.). The 

 sutures given in the present figures have been corroborated in at 

 least a dozen skulls, and there can no longer be any doubt about 



Fig. 2. — Labidosaurus{7). Skull, from the side. Three-fourths natural size. 

 No. 183. 



them. The figure given by v. Huene {op. cit.), I regret to say, has 

 a number of inaccuracies. There is a distinct quadrotojugal, a 

 bone found in nearly all the American Permocarboniferous reptiles; 

 there is no supratemporal, absent also in Procolophon and Cap- 

 torhinus; and no tabular, present in all other cotylosaurs, and 

 in many theromorphs. Of the structure of the under side of 

 the skull I have no corrections to make of my earlier figures. In 

 none of the large specimens is there a trace of the parasphenoid ; 

 it is certainly absent in some; in two of the smaller skulls it is 

 present though small. Perhaps its absence is a generic or a specific 

 character. Nor have I any changes to make in my figures of the 



