64 



MR. D. M. S. WATSON ON THE 



exactly in size and every point which can be compared with 

 A. curvimola. The section of the palate shown on its posterior 

 fracture is represented in text-fig. 20. 



There is a median element bearing a high dorsal ridge, now 

 detached, with a very deep groove on its mid-ventral surface and 

 carried out laterally in a long wing, which is overlapped by the 

 pterygoid. This bone bears a powerful irregular roughened 

 projection carrying small teeth: laterally its surface is smooth, 

 and is continued to the hinder end of the maxilla by that of the 

 ectopterygoid. The two bones scarcely meet, but are joined 

 together by a thin film of bone, undoubtedly the palatine, which 

 covers their dorsal surfaces. 



Text-figure 20. 



Arctognathus. Type-specimen of Lycosaurus tigrinus Owen. X §. 

 Obliquely transverse section as a plane corresponding to A A in text-fig. 19. 



If this section be compared with that which the palate of 

 Arctognathus would present if cut along the line A-A, there can 

 be no doubt, of the close affinity — indeed, specific identity— of 

 the two forms, for even the possible measurements are in very 

 close agreement. 



Thus we have confirmation for the view that the roof of the 

 median groove in the palate of Arctognathus is formed by a 

 median vomer. 



The epipterygoid of the type-specimen of A. curvimola is 

 shown to meet the parietal in a long suture, exactly as does that 

 of Diademodon. 



The preceding series of description is based on the more 

 complete and satisfactory remains of Gorgonopsids in the British 

 Museum, largely Endothiodon- zone forms. Of recent years 

 Broom and Haughton, either independently or together, have 

 described many complete Gorgonopsid skulls, chiefly from the 

 Cistecephahcs-zone. They have, however, never given so complete 

 an account of any form as that of Scymnognathus included in 

 this paper, and it is seldom that they have given more than one 



