SYSTEMATIC REVISION 



53 



The posterior border of the internal nostril marks a point half-way between the 

 posterior border of the anterior nostril and the anterior border of the orbit. 



"Measurements. nim 



"Total length of skull . 158 



Width posteriorly 152 



Width between nostrils 20 



Length from end of muzzle to posterior border of pterygoid plate 103 



Width between summits of ridges of vomer 10 



Length from posterior border of nostril to anterior border of orbit 41 



Lengthof longest maxillary tooth . 10 



Diameter of longest maxillary tooth at base 3.5" 



Revised description: The original description is correct except with regard to 

 the palate. The paired prevomers are plate-like and close the anterior portion of 

 the palate; following these are distinct palatine and pterygoid bones, the latter 

 coming close together in the median line. Conodectes may, as suggested by Williston, 

 be identical with Seymouria. 



FOREIGN FORMS. 



Genus PAREIASAURUS Owen. 



Owen, Cat. Foss. Rep. South Africa, 1876, p. 9. 



Seeley, Phil. Trans. Roy. Soc., 1888, p. 75. 



Broom, Annals South African Museum, vol. iv, 1903, p. 123. 



Bull. Am. Mus. Nat. History, vol. xxviii, art. xx, 1910, p. 201. 



Broom in his last paper gives the following summary oi Pareiasaurus: 

 "Though four fairly good skeletons of Pareiasaurus have heen discovered 



which reveal most of the general structure of the skeleton there are many details 



of which we are still ignorant. 



"The skull is large with the temporal fossae completely roofed over, but the 



detailed structure of the roof is still doubtful. There appears, however, to be littlt 



i 



Fio. 13 — Palate of Pareiasaurus. After Broom. Slightly restored. 



doubt that there is a quadratojugal. The bones are pitted somewhat like those 

 of Stegocephalians. There is a distinct septomaxillary. The palate is fairly well 

 known and, as shown in the figure (fig. 13), has the typical structure met with in 

 most primitive reptiles. There are paired prevomers bearing teeth, paired palatines 



