64 ME. E. LYDEKKEE OUT A lOlW 



latter suborder of the Crocodilia with the Sauropoda as for taking 

 the course proposed by Prof. Seeley. 



What, however, I have especially to say in regard to the Sauro- 

 poda, is to endeavour to point out the relationships of the two best- 

 known English genera, to notice a maxilla which I refer to one of 

 them, and also to show how extremely unsatisfactory is our know- 

 ledge in respect of other specimens to which generic names have 

 been applied. First, in regard to Ornithopsis, it appears to me to 

 be incumbent to take as the type of the genus, and therefore also 

 of the type species 0. Hulkei, the vertebra from the Isle of Wight 

 (B.M. No. 28632), which probably belongs to the anterior dorsal 

 region ; although I am aware that Mr, Hulke has proposed to take 

 in this sense the smaller Sussex specimen, described b}'' Prof. Seeley 

 as generically identical with the former, but which appears to me 

 as probably belonging to a different genus. 



The dorsal and cervical vertebrae of this genus, thus regarded, 

 closely resemble those of the American Brontosaurus, while the 

 resemblance between the ischium and pubis, figured by Mr. Hulke 

 in vol. xxxviii. pi. xiv., and the corresponding bones of the last- 

 named genus is (as Mr. Hulke has already indicated) so close as to 

 leave no doubt as to the near alliance of the English and American 

 forms. This being so, and seeing that Brontosaurus has amphi- 

 ccelous caudal vertebrae with closed chevrons, it becomes necessary 

 that I should retract the opinion expressed in a paper published in 

 the last volume of the Society's ' Journal ' * that the caudal vertebrae 

 on which Titanosaurus was founded might perhaps be referable to 

 OrnitJiopsis ; to the former genus I shall have to allude again, later 

 on, but its apparent distinctness from the latter removes all grounds 

 for referring that genus to a family distinct from the Atlantosauridse 

 of Prof. Marsh. 



Here I may notice a very interesting specimen which may, I 

 think, be probably referred to 0. HulJcei. Some years ago the late 

 Dr. Wright figured in the 'Annals and Magazine of Natural 

 History ' t a reptilian tooth from Brixton Bay, in the Isle of Wight, 

 of which he was unable to determine the affinity, the figure being 

 subsequently reproduced by Sir E. Owen in his ' British Eossil 

 Beptiles ' t and jDrovisionaUy referred to Cetiosaurus or Pelorosaurus, 

 This specimen has now come into the possession of the British 

 Museum (No. E. 964), and from its close resemblance to the tooth 

 of the American Morosaurus, figured by Prof. Marsh, there can be 

 no doubt that it belongs to the Sauropoda, while from its large size 

 I am inclined to refer it to Ornithojpsis rather than to Cetiosaurus. 

 A figure of its inner surface is given in Plate III. fig. 4. So far as 



* Vol. xlii. pp. 156-160. I take the opportunity of correcting two misstate- 

 ments on p. 159 of that paper. First, it appears that the beds regarded by 

 Prof. Marsh as Upper Jurassic are classed by Prof. Cope as Lower Cretaceous, 

 BO that Amphiccelias and Camarasaurus are of the same age as Brontosaurus, 

 and may be identical with that or some of the allied forms. Secondly, misled 

 by Sir R. Owen's reference of Iguanodont vertebrse to Cetiosaurus hrevis, I have 

 stated that the vertebral centra of that genus are solid. 



t Ser. 2, vol. x. p. 90 (1852). + Ser. 2, vol. iii. p. 422. 



