Dr. T. Wright on the Palaontology of the Isle of Wight. 89 



iiientary form ; the anterior cusp is absent at the base of the 

 external lobe, and the posterior cusp is a small process which rises 

 between the external and internal lobes. 



Locality. — I found this rare fossil in a bed of greenish tough 

 tenacious clay, being No. 35 of my section*, and which stratum 

 I have shown to be the equivalent of No. 14 of my section of 

 Hordwell, Beacon, and Barton Cliffsf^ from whence Mr. Falconer 

 obtained the specimen which formed the subject of Professor 

 Owen^s paper. It is important, therefore, to note that these 

 mammalian remains have been found in precisely the same geo- 

 logical horizon on both shores of the Solent sea ; thus affording 

 another link in the chain of evidence which proves the former 

 union of these tertiary beds. I have promised the loan of this 

 specimen to Professor Owen, who will figure it in the forthcoming 

 new edition of his ' British Fossil Mammalia ;' for this reason I 

 have not figured it here. 



Tooth of an unknown Saurian. 



I had the good fortune to meet with a very perfect reptilian 

 tooth in the Wealden clay of Brixton Bay; the accompany- 

 ing figure, of the natural size, was drawn on wood by Mr. W. 

 H. Baily, as it is important that palseontologists should possess 

 a faithful drawing of its singular form, to enable them to com- 

 pare future discoveries with the subject of this note, and even- 

 tually to determine the genus of Saurians to which it belonged. I 

 had the pleasure of showing this tooth to Professors Forbes, Ger- 

 vais and Owen, Dr. Mantell, and Messrs. Waterhouse and Wood- 

 ward, who were all unacquainted with the form. Dr. Mantell 

 thought it had some resemblance to a tooth found in the Wealden 

 of Tilgate Forest, and which he imagined belonged to the Hy- 

 laosaurits. " These teeth," he observes, " are about 1^ inch in 

 height, and commence at the base with a cylindrical shank, 

 which gradually enlarges into a crown of an obtusely lanceolate 

 form, convex in front, slightly depressed, and terminating in an 

 angular rounded apex, the margins of which are generally more 

 or less worn, as if from dentrition. The crown is solid, but the 

 fang encloses a small pulp-cavity ; the surface is enamelled, and 

 covered with very fine longitudinal striaj ; the base in every spe- 

 cimen appears broken transversely, and has not a smooth sur- 

 face, as if it had been loosened by absorption and shed natu- 

 rally X ■" The Doctor has given a figure of this tooth which dif- 



* Dr. Wright, Geology of the North-West coast of the Isle of Wight 

 (Annals of Nat. Hist. S. 2. vol. vii. p. 14). 

 t Annals of Nat. Hist. S. 2. vol. vii. p. 433. 

 X Hand-Book of the Fossils of the British Museum, p. 326. 



