182 



MR. R. lydi:kker ox remains of small 



11. On Remains of Small Sauropodous Dinosaurs from the. 

 Wealden. By it. Lydekker, Esq., B.A., F.G.8., &c. (Head 

 December 4, 1889.) 



[Plate IX.] 



Among the Dinosaurian remains from the Upi)er Jurassic of the 

 United States, recently described by Prof. Marsh, none are perhaps 

 more interesting than the vertebrse and teeth upon which the genus 

 Pleuroccelus^ has been based, since they indicate a comparatively 

 small form closely allied to the gigantic Morosaurus, and less nearly 

 so to the still more huge Brontosaiirus. In the type species of 

 Pleurocoelus the teeth are said to be of the same general type as those 

 of Morosaurus, but are not distinctly spoon-shaped, and are thus 

 more like a compressed cone. The centra of the dorsal vertebrae, 

 which are less than four inches in length, are elongated and very 

 markedly opisthocoelous, with a long and deep lateral cavitj^, of 

 which the upper portion gradually shelves towards the arch. 



Outer and profile views of a tooth of P/curoea'lu.s valdensis ; 

 from tlie Wealden. 



Recognizing the Sauropodous nature of the teeth from the Wealden 

 of Sussex and tlie Isle of Wight, provisionally referred by Mantell 

 and subsequently by Sir R. Owen to Hyloiosaurus (one of which is 

 shown in the woodcut), I proposed f some time ago to regard them 

 provisionally as indicating a European representative of the American 

 genus, with the name of Pleurocoelus valdensis. These teeth indicate 

 a very small member of the Sauropoda, and, although their crowns 

 are subject to considerable variation in form, many of them show 

 the absence of a decided spoon-shape, characteristic of those of the 

 type species. 



In the same notice I referred to the imperfect centrum of a dorsal 

 vertebra from the Wealden of Cuckfield, preserved in the British 



* Amer. Journ. ser. 3, vol. xxv. pp. 90-02 (1888). 

 t Geol. Mag. decade 3, vol. vi. p. 32r) (1889). 



