An almost Perfect Skeleton of Pareiasaurus serridens 125 



original type has either been badly weathered or imperfectly cleared 

 •of matrix, and in the cast it is impossible to tell what represents 

 bone and what matrix, so that one can only compare the larger 

 features. The present specimen is certainly distinct from P. haini, 

 and probably distinct from P. bombidens. 



In the present paper, while giving a description of the hmb bones, 

 vertebrae, and to some extent of the skull, I shall refrain from 

 dealing at length with the question of the affinities of the genus in 

 the hope that I may have an opportunity of examining a well- 

 preserved skull and thus be able to settle one or two points of 

 dispute in the anatomy before dealing with the affinities. 



The Skull. 



The skull differs from that of P. bombidens Ow., apparently in the 

 greater development of the "cheeks," and from P. baud Seeley, in 

 the greater prominence of the bony bosses. As these bosses are 

 well shown in this skull their arrangement will be described in detail, 

 as it will be of use for comparison with future specimens. 



Though a little difference can be detected in the relative degrees 

 of development of the tubercles and bosses on the two sides, the 

 arrangement is practically bilaterally symmetrical. Above each 

 orbit are three well-developed protuberances. The anterior one is 

 rounded and prominent ; the middle one much smaller ; and the 

 posterior very large but not greatly elevated. This third pro- 

 tuberance passes inwards towards the middle line almost half-way 

 from the margin of the orbit. Near the front of its inner end is 

 a small narrow tubercle. A little way behind the nostrils are a pair 

 of very prominent bosses about -OeSm. apart. A little tubercle lies 

 behind each, and another at the outer side. Between the anterior 

 supraorbital boss and the nostril lie a pair of moderate-sized pro- 

 tuberances forming part of a ridge that extends outwards from 

 the nasal boss. In the posterior part of the skull the large " cheek " 

 has its posterior border protected by a series of four large and two 

 smaller bosses. The two upper lie close together and are probably 

 both situated on the post-temporal, or as it is more usually, though 

 erroneously called, the " epiotic " bone. The inner is of moderate 

 size, but the outer very large and prominent. Below the large outer 

 tuberosity are two other large oval bosses. These are probably 

 situated on the " supratemporal," or, as it may perhaps be better 

 called, the prosquamosal bone. Under the second of this pair is a 

 small tubercle. At the lower angle of the cheek are two large oval 



