Proceedings of the British Association. 329 



been found in the Kimmeridge clay of Market Rasen, Weymouth, 

 and Shotover. From differences in the relative proportions of 

 these bones, Prof. O. considers them to have belonged to two 

 distinct species of Pliosaurus. The remains of the Saurians of 

 the crocodilian family, which complete the transition from the 

 Enaliosaurians to the terrestrial lizards, were next noticed. The 

 Report included descriptions of the fossil crocodiles in the British 

 formations below the eocene tertiary strata to the oolite inclu- ~ 

 sive ; and it was observed, that the extinct species deviated from 

 the organic type of the existing crocodiles, in proportion as their 

 remains occurred in strata geologically more remote from the 

 present time. Not any of the species were identical with those 

 now known to exist, and the modifications of structure in which 

 they differed, were much more considerable than any which dis- 

 tinguish the skeletons of existing species from each other. The 

 extinct species agreeing with the present crocodiles in possessing 

 the ball-and-socket articulation of the vertebrge, in which the 

 cavity is on the fore part, were first described. Of these, the 

 Crocodilus Toliapicus is found in the London clay of Bracklesham, 

 at Sheppey, and in beds of sand underlying the red crag at Ky- 

 son. The Crocodilus cultridens of the Wealden formation Prof. 

 O. now considered sub-generically different from the crocodiles, 

 and proposed for it the name of Suchosaurus. Goniopholis cras- 

 sidens, another species from the Wealden, was described by Prof 

 O. as more completely mailed than any of the crocodile family ; 

 its remains occur in the Tilgate Forest and near Battle Abbey, 

 and in the Purbeck limestone at Swanage. The next family of 

 extinct crocodilians considered by Prof. Owen, are characterized 

 by the biconcave structure of the vertebrae. Remains of the 

 first of these, Teleosaurus Chapmanni, are abundant in the lias 

 of the Yorkshire coast ; and T. Cadonensis, which abounds in 

 the oolitic formations near Caen, in Normandy, also occurs in the 

 oolite near Woodstock, and at Stonesfield. Remains of two other 

 species were noticed. The second genus, Steneosaurus, distin- 

 guished from the last by the sub-terminal position of the nostril, 

 is from the Kimmeridge clay at Shotover, and from the oolite of 

 Stonesfield. One of the most interesting specimens, exhibiting 

 the form of the brain in a cast of that part, is in the Woodward- 

 ian Collection at Cambridge. A third division was for the first 

 time described as occurring in British strata, possessing the ball- 



Vol. xLii, No. 2.— Jan.-March, 1842. 42 



