326 CLASS xv. 



Sp. Suchosaurus cultridens, the only species known; from the Wealden: 

 OWEN Rep. Br. Assoc. 1841, p. 67, and Odontoyraphy. 



Goniopholis OWEN. Dermal plates strong and bony, quadrilateral, 

 with a conical process received in a corresponding depression of the 

 neighbouring plate. 



Sp. Goniopliolis crassidens; crown of teeth remarkably thick and obtuse, 

 ribbed: vertebrae nearly flat at both ends ; Wealden. 



Poikilopleuron DESLONGCHAMPS. Vertebrae slightly biconcave. 

 The posterior ventral ribs are composed of two pieces held toge- 

 ther by ligament and channelled above ; in this channel rests 

 another rib formed like an S by its ventral portion, whilst the pos- 

 terior part is in connexion with the spinal column. 



Sp. Poikilopleuron Bucklandii; this is the only species known; it was dis- 

 covered in the oolite of Caen ; its length is estimated at twenty-five feet. 

 DESLONGCHAMPS in M6m. de la Soc. Linn, de Normandie, 1836, vi. 

 P- 33- 



Cetiosaurus OWEN. Vertebrae biconcave, breadth and depth 

 great in comparison of length. Wealden and lower Oolite. 



Some of the species surpassed all the modern crocodiles in size, and even 

 rivalled the whales. "In the great expanse of the coraco'id and pubic 

 bones, as compared with the Teleosauri and crocodiles, the enormous 

 Cetiosauri manifested their closer affinity to the Enaliosauria." OWEN 

 Report Brit. Assoc. 1841, pp. 94 102. 



Dinosauria OWEN. 



These gigantic animals made the nearest approach to mammals. 

 The anterior thoracic ribs had a two-fold articulation to the spinal 

 column as in crocodiles. Hence it may be supposed that the respi- 

 ration was similar, and the heart with four chambers. The pectoral 

 arch was lacertine ; the sacrum composed of at least five anchylosed 

 vertebrae. The bones of the extremities had a large proportional 

 size for Saurians, and were provided with large medullary cavities. 

 Hence their habits were terrestrial. See OWEN Rep. 1841, pp. 

 102144. 



Megalosaurus Cuv. 



Sp. Megalosaurus Bucklandi Cuv. Teeth in distinct sockets, of which the 

 outer rim is much the highest, compressed, conical, pointed with trenchant 

 and serrated anterior and posterior edges ; become solid in the course of 

 development ; the smooth anterior surface presents fine polished wrinkles. 

 Vertebrae with articulating surfaces nearly flat. Probable length thirty 

 feet. Wealden and Oolitic periods. 



