340 



Prof. H. G. Seeley. 



[May 12, 



There is no evidence of limb-bones. 



The other remains which have been attributed to Parieasaurus are 

 referred by the anthor to a new genus named Phocasaurus. This is 

 founded upon the ilium originally attributed to Parieasaurus, and the 

 bones hitherto regarded as the anchylosed scapula and coracoid, are 

 now regarded as the anchylosed pubis and ischium of the same 

 individual animal to which the ilium belongs. The ilium is inter- 

 mediate between that of an Ornithosaur and the ilium of a seaL 

 The further detailed discussion of Phocasaurus is reserved. One 

 ilium attributed to Parieasaurus is referred to Dicynodon. 



Parieasaurus is placed in the sub-order Parieasauria, which is- 

 grouped under the Anomodontia. 



On comparison of Parieasaurus with reputed Dinosaurs from South 

 Africa, it is shown that although the teeth of Anthodon resemble 

 those of Acanthopholis, the bones of the post-orbital region of the 

 skull are arranged upon the Labyrinthodont plan which characterises 

 Parieasaurus. There is no evidence of the affinities -of Tapinoce- 

 phalus except the sections of the teeth, but since they are hollow and 

 implanted as in Parieasaurus, it is probable that that genus also is not 

 Dinosaurian. The only Dinosaurs known from South Africa are the 

 genera Orosaurus and Euskelesaurus described by Professor Huxley 

 in 1866. 



Concerning the affinities of Parieasaurus, the author interprets the 

 blending of Labyrinthodont and Reptilian characters on the hypo- 

 thesis that Parieasaurus exhibits a transition from the Amphibia to 

 the Reptilia. The animal is regarded as technically a reptile ; but as 

 showing both in the skull and vertebral column characters which are 

 typically Labyrinthodont, though they are for the most part unknown 

 among existing Amphibians. The Reptile order to which the resem- 

 blances come closest is the Anomodontia. And since the resemblance 

 in the sacrum and pelvis amounts to absolute coincidence in plan, and 

 in the palate to close approximation, it is inferred that the cranial differ- 

 ences which separate Parieasaurus from the Anomodonts are no more 

 important than those which distinguish the skull of a turtle from the 

 skull of a tortoise ; and that with the acquisition of the single basi- 

 occipital condyle there came about a gradual loss of the distinctive 

 Labyrinthodont characters. But the Labyrinthodontia is a large 

 group including many sub-orders, some of which approximate to 

 living Urodeles, others to living Reptilia, and yet others to fossil 

 Reptilia. It is urged that the Ichthyopterygia form the most primi- 

 tive order, derivative from the Labyrinthodont group, having lost the 

 epiotic bones but retaining the post-orbital and supra- temporal with the 

 covered quadrate bone ; that the form of vertebra in Ichthyosaurus with 

 its articular tubercles for the rib, reproduces the vertebra of Eosaurus 

 and Anthracosaurus and other Labyrinthodonts, while the dorsal ribs 



