OF THE MAASTRICHT BEDS. 253 



compressed, and one third on the inner side, which is necessarily 

 more oblique and rounded. 



Since the head of the bone is nearly at right angles to the distal 

 end, it necessarily happens that there is no appreciable increase in 

 width as the bone extends proximally. But on the external surface 

 the bone curves a little outward and forms a compressed area, convex 

 from front to back, which terminates proximally in two small convex 

 condylar surfaces (fig. 3, b). The internal aspect of the proximal 

 surface is decayed, so that no account of it can be given. 



The cnemial crest (fig. 3, a, c) was evidently' developed on the 

 Iguanodont plan ; but its proximal portion has been sawn away. 



The anterior outline of the bone, as preserved, is concave ; the 

 posterior outline is sigmoid (fig. 3, a). The posterior surface shows 

 at 12 cm. (4yZ(5- in.) from the proximal end a large vascular perfora- 

 tion in the bone, which, as it rises proximally, becomes a groove 

 (fig. 3, A). 



As compared with Iguanodon this specimen differs chiefly in being 

 more slender and in some details of conformation of the distal end. 

 But although the differences are suggestive of generic distinction, 

 the condition of preservation does not admit of the enunciation of 

 generic characters. On the other hand the form closely approxi- 

 mates to Hadrosaurus, and is certainly intermediate between Igua- 

 nodon and that type * ; and this combined with the characters of the 

 femur indicate a divergence from Iguanodon in the same direction as 

 m that bone, which justifies the association of the tibia, femur, and 

 metatarsal bone. The metatarsal bone is too imperfect for descrip- 

 tion, but it differs in form from any similar bone that has been 

 figured. 



Discussion. 



The President remarked upon the interest attaching to these 

 latest known of the Dinosaurs. 



Dr. Woodward referred to an Iguanodont vertebra in the British 

 Museum which was dredged from the Dogger Bank. Possibly this 

 was derived from the Maastricht beds, and Prof. Seeley might be 

 able to associate it with the bones described in the paper. 



The Author stated that many Iguanodont remains were found in 

 the Crag and the Drift ; but it would be unsafe to infer any possible 

 relations to one another. 



* It may be also compared with the tibia referred to Megalosaurus by Prof. 

 Owen (Rept. Weald, part iii., 1856), but will be seen to be of distinct type. 



Q.J.G.S. No. 155. 



