An almost Perfect Skeleton of Pareiasaui'us serridens 127 



■apparently 7 cusps. The posterior teeth — at least from the 7th tooth 

 — are longer than they are high, and have 9 cusps. The front teeth 

 have the cusps arranged as follows : — 3 subequal on the top followed 

 on each side by another, and considerably further down by a second. 

 Whether there may be another very small pair making 9 altogether 

 is not evident. The posterior teeth have 5 subequal cusps arranged 

 round the top, followed on each side at a little distance by a larger 

 cusp and then by a second large cusp, making 9 altogether. None 

 ■of the teeth show any appearance like that figured by Seeley in the 

 teeth of P. russouioi. 



The following are some of the principal tooth measurements : — 



The 7th upper tooth measures in length 16mm. 



,, 8th ,, ,, ,, „ height 15mm. 



M 2nd „ ,, ,, „ length 15mm. 



,, ,, ,, ,, ,, ,, height 21mm. 



The VERTEBR.E. 



There are 20 presacral vertebrae, 2 sacral, and probably 30 caudal 

 vertebrae. In Seeley's first paper on Pareiasaurus he gives the 

 number of presacral and sacral vertebras in P. bombidens as 18 

 and 2, and definitely states that " no bone is missing from any 

 part of the column." In his second paper, in describing a second 

 specimen of P. bombidens he says, " 19 presacral vertebrae are 

 preserved." In P. baini there are stated to be 18 presacral 

 vertebrae. 



The various vertebr® do not differ very greatly from those of 

 P. baini. 



The centrum of the atlas, though distinct from the axis, is so 

 closely united to it that there was probably very little movement if 

 any between the two bones. The arch of the atlas, of which a small 

 portion remains, was probably very small, I find no evidence of any 

 ribs having arisen from the atlas. The axis is represented only by 

 the body. It has given articulation to a fairly strong two-headed 

 rib. The lower articular surface is near the middle of the body, the 

 other on a level with its top. A small intercentrum has lain between 

 the atlas and axis and a larger intercentrum between the axis and 

 the 3rd cervical vertebra. 



The 3rd, 4th, and 5th cervicals resemble each other fairly closely. 

 The body of each has two articular surfaces for each rib, the lower 



