Fauna and Stratigraphy of the Slormberg Series. 387 



The suture between the basioccipital and basisphenoid is not 

 traceable, but I am inclined to believe that it runs along the trans- 

 verse ridge. If this be so, the structure is different from that of 

 Sphenosuchus, where the suture runs along either side of the inter- 

 tympanic foramina which lie wholly in the basioccipital, and agrees 

 with that in Plateosaurus and Thecodontosaurus. The median ex- 

 cavation is smaller than in Sphenosuchus. The distance between the 

 hinder end of the basisphenoid and the pterygoid apophyses of the 

 bone is comparatively greater than in Thecodontosaurus. These 

 apophyses are as in the European genus. Seen from above the 

 anterior portions of the two apophyses meet superiorly to form a 

 crest in advance of the circular hole for the hypophysis cerebri 

 (pituitary fossa). The basisphenoid is furnished laterally just behind 

 the root of the pterygoid apophysis with a deep groove corresponding 

 in position to the recessus basisphenoidei of Thecodontosaurus figured 

 by von Huene. The bottom of this pit is presumably pierced by the 

 carotid foramen opening into the pituitary pit. Superiorly the relation 

 of the basisphenoid with the bones of the side-wall of the brain 

 case are obscure. 



The foramen ovalis is only presented in section on the left side. 

 It occupies the same position as in Thecodontosaurus, perforating the 

 side-wall of the brain behind the sella turcica. 



The exoccipital is of the form seen in Thecodontosaurus. Its lower 

 border is grooved proximally, the groove running inwards and forwards 

 to the foramen lacerum for the exit of nerves IX-XI. This opens 

 into the bottom of the side-wall of the brain-case. Separated from 

 this foramen by a thin plate of bone is a larger opening, the foramen 

 jugulare for the passage of the VHIth nerve. Mesial to the internal 

 opening of this foramen is a shallow pit in the brain case. The 

 opening for the Xllth nerve is only seen in vertical section passing 

 through the exoccipital above the level of the condyle. Behind and 

 above the foramen lacerum the side wall of the brain is furnished 

 with two small foramina, presumably venous. 



The exoccipital articulates with the basioccipital below and the 

 supraoccipital above. It has a strong paroccipital process. 



Save in details of relative sizes, this basicranium is similar to that 

 of Thecodontosaurus, and differs in certain features more from 

 Sphenosuchus. 



A portion of the right side of the skull and lower jaw is preserved, 

 attached to a part of the top of the skull. The snout is missing. 



The orbit was large, its length as preserved being 54 mm. Its 

 anterior border is formed by the pillar-like lachrymal which divides 



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