Fauna and Stratigraphy of the Stormberg Series. 381 



form are longer than those of Massospondylus carinatus. The relations 

 of the lengths of the metatarsals in Massospondylus harriesi is different 

 from that in our form. In Massospondylus harriesi metatarsal II is 

 longer than metatarsal IV, whereas in our form metatarsal II is 

 shorter than metatarsal IV. 



In comparing with Ammosaurus and Gijposaurus I need only refer 

 to the great difference in the ilea. 



The only other genus of the family is Thecodontosaurus. Super- 

 ficially there is great resemblance between our form and the known 

 species of Thecodontosaurus. A closer study, however, reveals remar- 

 kable differences. 



A comparison of the ileum of our form with, that of Thecodonto- 

 saurus antiquus shows that in the latter the spina posterior is much 

 more produced. The acetabulum cuts deeper into the ileum of our 

 form, which resembles the Plateosauridae in this respect. The 

 highest point of the acetabular concavity is situated much nearer 

 towards the middle of the bone than in our form, and this is another 

 point of resemblance with the Plateosauridae. The ilium of our form 

 is manifestly different from that of Thecodontosaurus cylindrodon, and 

 also in the direction of the Plateosauridae. 



The pubis of our form differs considerably from that of Thecodonto- 

 saurus antiquus, as far as the latter is known. In our form the 

 lateral edge of the pubis is regularly concave, whereas in Thecodonto- 

 saurus antiquus its upper end is sigmoidal. There is also great 

 difference in the shape of the pubic foramina. The shape of the 

 proximal end of the ischium of Thecodontosaurus antiquus, as far as 

 preserved, is quite different from that of our form, a, difference 

 which is best understood from a comparison of the figures. 



Another difference becomes conspicuous when the length of the 

 humerus is expressed in lengths of dorsal vertebrae. Taking one of 

 the hinder vertebrae v. Huene came to the following results: In 

 Thecodontosaurus antiquus the humerus is about five times as long 

 as the vertebra, and in Thecodontosaurus skirtopodus about four and 

 a half times. In our form the length of the eleventh dorsal vertebra 

 is 29 mm. The length of the right humerus is 93 mm., which 

 means that the humerus is only 3'2 times as long as the vertebra. 

 Therefore, the humerus of our form is relatively much shorter than 

 that of Thecodontosaurus antiquus and of T. skirtopodus. 



There is great difference between the ischium of Thecodontosaurus 

 minor and that of our form. 



The points of difference enumerated above show sufficiently that 

 our form does not belong to any of the known genera of the Anchi- 



