Notices of Memoirs — G. A. Boiilenger — Triassie Re])tilia. 357 



As in Syperodapedon, the nasal aperture is single, but, in 

 accordance with the shape of the premaxillaries, it is more elongate, 

 its length being to its width as 2^ : 1 ; its posterior border extends 

 to the level of the orbits, which are entirely directed upwards. The 

 inter-orbital region is narrow, especially behind. The supra- 

 temporal fossae are very large, separated from the orbits' by the 

 narrow post-orbital arch and from each other by the sharp median 

 crest of the parietals. The latero-temporal fossa is kidney-shaped, 

 and proportionately larger than in Hijperodapedon, but smaller than 

 the supra-temporal fossa. The maxillary bone is deep and nearly 

 vertical, with an oblique ridge extending downward and backward 

 to the jugal; the maxillary teeth, so far as they are preserved, 

 appear very similar to those of Hyperodapedon, and form a single 

 series in front and two behind. The palate is imperfectly preserved, 

 but what is left of it agrees in essential points with Hyperodapedon ; 

 the palatine teeth are disposed in three series behind. 



3. Ornithosuchiis Woodwardi, E. T. Newton. 



The specimen on which this species was founded by Mr. Newton 

 in 1894 indicated a reptile about 2| feet long. Specimens more 

 than twice as large are now described, and afford much information 

 •on points which remained obscure. Clavicles were present, large 

 and widely expanded at their inner extremity, where they over- 

 lapped the inter-clavicle. A plastron, or system of abdominal ribs, 

 was also present, resembling very closely that of Sphenodon, each 

 segment being formed of a median angulate piece, to which a lateral 

 limb is attached, the segments, however, being much more numerous 

 and closer together than in the New Zealand reptile. 



The presence of clavicles and of a plastron show that OrnitJiosucTius 

 cannot be included among the Dinosaurs, as originally suggested, 

 but must be placed in the order Thecodontia of Owen, which 

 contains Belodon and Aetosaiirus. The Thecodontia should be kept 

 distinct from the Crocodilia or Emydosauria ; they agree with the 

 latter, the Dinosauria, and the Pelycosauria, to which they are 

 very closely related, and differ from the Ehynchocephalia, in the 

 truly thecodont dentition ; they agree with the Rhynchocephalia 

 and Pelycosauria, and differ from the Emydosauria and Dinosauria, 

 in the presence of clavicles, whilst they show close resemblance to 

 the Ehynchocephalia proper in the structure of the plastron. The 

 presence of clavicles' and the condition of the pelvis, in which the 

 pubis enters the acetabulum, together with other characters showing 

 greater generalisation, afford ample justification for the separation of 

 the Thecodontia or Parasuchia, as a group of ordinal rank, from the 

 Emydosauria. The author also expresses the opinion that precision 

 in the definition of the higher group of reptiles would gain much 

 by the order Dinosauria being restricted to the carnivorous, truly 

 thecodont forms, the others deserving to form an equivalent order 

 under the name of Orthopoda,Cope (Predentata, Marsh ; Ornithischia, 

 Seeley). 



