1845.] MANTELL ON THE WEALDEN OF^TITE ISLE OF WIGHT. 95 



sptindylus and Iguanodon are the most numerous. The author di- 

 rects especial attention to a large thigh-bone together with portions 

 of ribs and vertebras (exhibited to the Meeting when this paper was 

 read) which he obtained lately from the clay at the foot of the cliif 

 near Brook. The thigh-bone is three feet four inches long ; it well 

 exhibits the peculiar characters of the femur of the Iguanodon, 

 namely, the head with its flattened lateral trochanter, the middle of 

 the shaft with the mesial lateral process, and the inferior extremity 

 with its double condyles separated by a deep sulcus or furrow both 

 anteriorly and posteriorly. With this femur was found a tooth, frag- 

 ments of ribs and other bones, and several vertebrae, caudal and 

 dorsal. The tooth is large and worn down to a stump, and the fang 

 has been absorbed owing to the pressure of a successional tooth. 

 Like the femur it evidently belonged to an aged animal, and very 

 probably to the same individual. The caudal vertebrae may also be 

 assigned to the same reptile without hesitation, but the dorsal ap- 

 pears to be referable to the Cetiosaurus. 



Another bone of Iguanodon to which the author directs particular 

 attention is from Sandown Bay, the locality whence was obtained a 

 large toe-bone, figured by Dr. Buckland in the Geological Trans- 

 actions*. This specimen is the low^er extremity of a tibia, or large 

 bone of the leg, and its proportions are more colossal than those of 

 any bone of this reptile hitherto described. The Sandown speci- 

 men exceeds by four times in linear dimensions the tibia of a young 

 Iguanodon from Tilgate Forest one foot in length. It was therefore 

 probably four feet long when entire ; and from the relative propor- 

 tion of the thigh-bone and leg-bone of the Iguanodon, as shown by 

 specimens of the same individual in the British Museum, the femur 

 of the limb to which this tibia belonged must have measured five 

 feet, so that the entire length of the leg and thigh would be nine 

 feet. 



Besides these bones, the author has collected a fine metatarsal 

 from the Wealden near Atherfield, as well as several very large and 

 well-preserved vertebrae of the Streptospondylus, and fragments of 

 the ribs of a large Iguanodon. 



Section of the Wealden strata exposed by the cutting in the Timhridge 

 Wells Railway near Timhridge, 



"As connected with the subject of tliis paper, though situated in a 

 district remote from the Isle of Wight, I add a few remarks on a 

 section of the Wealden beds recently exposed, which is so interest- 

 ing and so easily accessible, and may possibly be so soon obliterated, 

 that a brief notice of it will bo useful. 



" This section has been formed by the cutting for the railway lately 

 opened from Tunbridge to Tunbridge Wells, the line traversing 

 Wealden strata along the whole distance, Innnediately on leaving 

 the Tunbridge station tliere is a deep cutting which ex])oses two 

 bands, from three to four feet thick, of fawn-coloured sandstone rc- 

 * Geol. Trans., 2iid Scr. vol. iii. pi. 41. 



