PKOCOLOPHONID^}. 13 



Seeley (Phil. Trans, for 1889, p. 272, pi. ix. figs. 7-9) regards the 

 large bone identified by Owen (Cat. Foss. Rept. S. Africa, pi. xx 

 fig. 6) with the squamosal (27 in figure) as the quadratojugal. The 

 extension of this bone behind the quadrate, which Seeley remarks 

 is so peculiar in a quadratojugal, is characteristic of a squamosal (as 

 in Chelonia), and it seems more probable that the bone in question 

 represents a squamosal or supratemporal rather than a quadrato- 

 jugal. 



Family PROCOLOPHONID^. 



Dentition of a carnivorous type, but not differentiated into 

 incisors, tusks, and cheek-teeth ; marginal teeth completely anchy- 

 losed to the bone, and teeth borne upon the vomer and pterygoids. 



Genus PROCOLOPHON, Owen 1 . 



The type and only described genus. Skull short, triangular, and 

 somewhat depressed, with a straight posterior border ; its general 

 contour approximating somewhat to that of Sphenodon, but with a 

 much shorter postorbital portion. Premaxillse projecting in advance 

 of mandibular symphysis, which is but loosely united. 



Procolophon trigoniceps, Owen 2 . 



Syn. Procolophon griersoni, Seeley 3 . 



The type species. Of the approximate size of Sphenodon punc- 

 tatus ; skull somewhat convex, with a comparatively narrow inter- 

 orbital bar, and a broad lateral plate of bone in the quadratic 

 region. 



Hob. South Africa. 



R. 1726. The imperfect skull ; from the Karoo system of Tafelberg. 



{Fig.) The type specimen ; figured by Owen in his ' Catalogue 

 of the Fossil Reptilia of S. Africa,' pi. xx. figs. 4-7. 

 From the imperfection of this specimen it was considered 

 that the genus had a single narial aperture; the notch 

 marked as the temporal fossa in the figure is really the 

 notch at the side of the occiput. The skull figured by 



1 Cat. Foss. Kept, S. Africa, p. 25 (1870). 



2 Loc. cit. 



3 Quart. Journ. Geol. Soc. vol. xxxiv. p. 797 (1878). 



