TJtc President's Address. By Dr. H. Woodward. 147 



on the sea-weeds just below low-water mark. This theory would 

 afford an explanation of the long, slender neck. The animal, on 

 account of its great weight, would be able to walk in tolerably- 

 deep water and reach the surface to breathe, by means of its neck 

 without the necessity of swimming. 



Another remarkable form met with in America is named 

 Diplodocus. 



The orbits are large and placed far back in the cranium ; the 

 facial portion is elongated and broadened in front; the nasal 

 opening is very large and placed near the apex of the skull. The 

 teeth are very weak, slender, and cylindrical in shape, like a row 

 of bluntly rounded pins, and are all crowded to the front of the 

 jaw, twenty-six above and twenty below, forty-six in all. No- 

 restoration of this Dinosaur has been attempted, but it is believed 

 to have been from 40 ft. to 50 ft. in length. The teeth indicate a 

 herbivorous diet, the animal feeding largely upon succulent vege- 

 tation, and the position of the nares seems to indicate an aquatic 

 mode of life. Morosaurus is placed near to Diplodocus. The 

 limbs suggest a plantigrade progression, as in Brontosaurus. There 

 does not appear to be any representative of Diplodocus out of North 

 America. 



Some of the Dinosaurs had a remarkable defensive armour : for 

 instance, Stcgosaurus had a row of enormous vertical plates forming 

 a single series and reaching from the head to the tail, the extremity 

 being armed by one or more pairs of large spines ; the head was 

 very small, as in Brontosaurus. We have in this country an inter- 

 esting example of an armoured Dinosaur in Scelidosaurus Harrisoni 

 from the Lias of Dorsetshire ; the back was protected by plates and 

 spines ; there were also lateral rows of smaller tubercles ; the head 

 was small and furnished with teeth, like those in the Iguanodon. 



Triccratops was a large Cretaceous Dinosaur, the head being 

 6 ft. in length and broad in proportion ; it had a huge bony frill 

 margined by tubercles, covering the back of the neck and joined 

 to the skull. A pair of bony horns were placed, one over each eye, 

 covered in life by a horny sheath, and a smaller central one over 

 the nasal bones ; the extremity of the beak was provided with a 

 horny bill, both in the lower and upper mandible. The cheek 

 teeth are very singular among reptiles, having two distinct roots, 

 placed transversely in the jaw, with a separate cavity for each 

 fang ; this structure in the teeth is truly remarkable, being charac- 

 teristic of the Mammalia. 



One of the earliest Dinosaurs known in this country is the 

 Iguanodon, originally described by Dr. Mantell and more fully by 

 Prof. Owen, but neither of these anatomists had anything but very 

 imperfect remains and detached bones to guide them in arriving 

 at a correct idea of the form of the entire animal. Mr. Water- 

 house Hawkins, in 1857, commenced a series of restorations of 



