On the Skeleton of a New Pareiasaurian. 21 



height, 119 mm.; height of spine, 48 mm.; width between points 

 of postzygapophyses, 74 mm. 



The vertebrae from the 10th to the 19th are roughly similar, 

 increasing gradually in size and strength backwards. The neural 

 spines become longer and more regularly diamond shaped in section. 

 The 16th to 19th inclusive differ from the others in that the centra 

 in these are considerably wider than long. The following give the 

 measurements of one of each of the typical vertebrae : 



12th (anterior dorsal) : length of centrum, 59 mm. ; width of 

 centrum, 60 mm. ; distance between points of transverse processes, 

 154 mm. ; distance between points of postzygapophyses, 128 mm. 



18th (posterior dorsal) : length of centrum, 52 mm. ; width of 

 centrum, 65 mm. ; whole height, 163 mm. ; height of spine, 

 38 mm. ; distance between points of transverse processes, 174 mm. ; 

 distance between points of postzygapophyses, 165 mm. 



The articular surface for the 13th rib is 62 mm. long, while that 

 for the 18th rib is 34 mm. long. The surfaces decrease in size on 

 passing backwards. 



The sacrum consists of four anchylosed vertebrae, differing thus 

 from that of Pareiasaunis serridens, in which the sacrum is formed 

 of two vertebrae only. The sacral vertebrae diminish in length and 

 width from the first to the last, while the following give the 

 heights : Whole height : 20th, 138 mm. ; 21st, 107 mm. ; 22nd, 

 103 mm. ; 23rd, 120 mm. ; height of dorsal spine, 43 mm., 40 mm., 

 40 mm., 48 mm. respectively. The first sacral pleurapophysis is very 

 massive. From the body of the vertebra to the ilium it measures 

 158 mm., while its articulation with the ilium measures 127 mm. in 

 length. The articular surface is hollowed out into a deep groove, 

 which accommodates the inwardly bent lower portion of the anterior 

 part of the ilium. The second and third sacral ribs are compara- 

 tively small and thin, and apparently coalesce into a single thin 

 plate above the posterior part of the articulation of the ilium and 

 first sacral rib. The fourth sacral rib is stouter, being 82 mm. long 

 and 50 mm. broad. The last three ribs seem to have been attached 

 to the ilium partly by ligament. 



The caudal vertebrae present are 11 in number, and decrease 

 regularly in size : the 1st is 110 mm. high, the llth 50 mm. The 

 first six resemble the praesacrals in form, having similar dorsal 

 spines and bodies. From each side of the centra of these six lateral 

 processes are formed, the longest being 72 mm. long. Chevrons 

 begin on the 7th caudal. The series is incomplete. 



A fairly complete set of ribs is preserved. The largest measures 



