On some Goryonops'um Skulls. 505 



Since the publication of the original description of this species the 

 palate of the type lias been almost fully cleaned: and its features 

 are such that it has been thought advisable to separate this and the 

 preceding form from the very different Scymnognafhus whuitsi and to 

 erect the new genus Aelurof/nuthux for their reception. It is possible 

 that this genus mav also include other forms from the Cistecephalus 

 zone, such as minor and atit/nstfcejjy. which have hitherto been as- 

 signed to the Kndothiodon /one gem is Scifinnognathus. 



The median portion of the palate is excavated into a very narrow 

 and deep groove bordered by strong tooth-bearing ridges formed by 

 the palatines and pterygoids. The median groove is seemingly pier- 

 ced by an interpterygoid foramen. The pterygoid has a short ante- 

 rior prolongation on the roof of this vaulted area, but there is no 

 median vomer seen on the palate. The posterior nares extend far 

 back to the level of the last molar. The interclioanal bar is 



ridged on its ventral surface. Superiorly it forms a thin median 

 plate with a grooved dorsal edge: this plate is pierced posteriorly 

 by a large transverse foramen. The relations of the prevomer, 

 pterygoid and palatine in their vertical portions seem to be as in 

 the skull which is later to be described as Arctognaihus whalfsi. 



The sphenethnioid meets the frontals and parietals and ventrally 

 touches the median plate formed by the pterygoids and basisphenoid. 



The ventral surface of the palate is essentially similar to that of 

 the Aelurosaurid ligured by Watson. The pter\goid Mange is very 

 massive; and as in Aelurosaurus the ectopterygoid forms the lateral 

 portion of its front face. 



The snout is deep and of rounded section, higher than broad. 

 There is no "step" in the maxillary border. The septornaxilla has 

 a large facial portion with strong tnrbinal processes: the septo- 

 rnaxillary foramen is fairly large. The anterior end of the nasal 

 slightly overhangs the nostril. There is a pronounced antorbital 

 depression, more pronounced than in A. tigriceps. 



GORGONOGNATHUS LONGIFRONS, Htn. 



1<>15. Haughton. Ann. S. Afric. Mus. XII, 3. p. 84. PI. XIII, 

 figs. 13. 



1918. Haughton. Ann. S. Afric. Mus. XII. 6. p. t>09. figs. 56, 57. 

 1921. Watson. Gorgonogndthus. Proc. Zool. Soc. p. 78. 



The type specimen has been split longitudinally in the posterior 

 half, and shows the general shape of the brain-case, although it is 

 not possible to remove the matrix and expose the foramina for the 



