An almost Perfect Skeleton of Pareiasaurus serridens. 137 



blance to that of the Anomodonts, is essentially very dissimilar, 

 inasmuch as the Anomodonts have a small though distinct obturator 

 foramen, and some of the Theriodonts have a large obturator 

 foramen, while in Pareiasaurics there is merely a pubic foramen. 

 In P>vcolop]io}i also there is a pubic foramen, but the type of pelvis 

 differs considerably, as in it the pubis and ischium are plate-like bones 

 held together by cartilage. 



The femur of Pareiasaurus differs considerably from that in 

 Procolophon, and resembles, at least superficially, rather that of 

 the Anomodonts. The femur in the Pelycosaurians is apparently 

 of a type somewhat similar to that of Pareiasaurus, as are also the 

 tibia and fibula. In Procolophon the tibia and fibula also bear some 

 resemblance to those bones in Pareiasaurus. 



In Procolophon the tibiale is united with the intermedium, and 

 there is a distinct fibulare. If the fibulare were also united there 

 would be produced a proximal tarsal bone such as is found in 

 Pareiasaurus. 



In conclusion, I must express my indebtedness to Mr. Eogers and 

 Mr. Schwarz for the care they have taken in collecting the fragments, 

 and to Miss M. Wilman for the great assistance she has given me in 

 the development of the specimen. 



