Anomodont Skull- 77 



Wliethei" the element behind the parietal is to be regarded as 

 the iuter-parietal or supra-occipital it is at present difficult to 

 decide. 



It will be observed that in general structure the cranio-facial 

 axis of the Anomodont bears a much greater resemblance to that 

 of the mammal than to that of either the tortoises, the li/.ai'ds or 

 the birds. 



II. — The Relations op the Juoal. 



Though in all the Anomodonts the jugal may be said to 

 articulate with the maxilla in front and the squamosal behind, 

 and to form the lower border of the orbit, it differs in its relations 

 in diffei-ent members of the group so greatly that some account of 

 the conditions seems advisable. 



In Oude/iodoti f/'igoiiiccps the jugal forms almost the whole 

 of the suborbital arch. On its outer and under side it is over- 

 lapped by the posterior part of the maxilla, which reaches to a 

 point a little beyond the level of the middle of the orbit. At the 

 posterior and inferior angle of the orbit the post-orbital (post- 

 frontal) meets the jugal so that the latter forms practically no part 

 of the posterior border of the orbit. The jugal, however, sends u}) 

 a strong process along the posterior and inner side of the post- 

 orl)ital and thus forms the greater part of the lower half of the 

 ])ost-orl)ital arch. Immediately below the point of articulation 

 of the lower end of the post-orbital lies the anterior end of the 

 zygomatic process of the squamosal on the outer side of the jugal, 

 but not articulating with the post-orbital. The posterior or 

 zygomatic portion of the jugal passes along below the squamosal 

 and forms the lower border of the anterior two-thirds of the 

 zygomatic arch. It forms the inner stirface of most of the anterior 

 lialf of the arch, Init only a very small part of the upper 1)order. 



In Oudf'iKxioii t)'iiricahis the anterior part of the zygomatic 

 process of the squamosal is much better developed, and the 

 posterior part of the jugal less developed, so that the jugal forms 

 oidy about a third of the lower border of the zygomatic arch. 

 Otherwise the relations of the bones are pi-ecisely similai- to those 

 found in O. triyoniccp.s. 



In Oudcnodon gracilis the suborbital arch is not very well 

 shown in the type ; but it appears that the maxillary does ii(<: 



