M. Marcou thought that the difficulties in regarding these beds as of freshwater origin were greater than the author supposed. The absence of fossils in gypsum, though almost universal, was not total. He had himself seen three specimens of Trigonia in gypsum from Stuttgart.
Mr. Tate mentioned the discovery by Mr. Burton of marine fossils in the Bed Marl, in one instance in combination with vegetable remains. He commented on the sharp demarcation observable in Ireland between the Rhaetic beds and the marl below, whereas it was almost impossible to separate them from the Lias above. He doubted, however, whether the true relations of the Rhætic beds were to be worked out in this country. As to the fossils of the Sutton Stone, they were all purely Liassic.
Mr. Burton stated that the fossils from the Bed Marl came from a spot about five miles from Retford, in the direction of Gainsborough, but he had not seen them in situ. There are, however, no Rhætic beds within some miles.
The Rev. Mr. Winwood, in the absence of Mr. C. Moore, from ill health, inquired whether the author regarded the White Lias as Rhætic, or Liassic.
Prof. Ramsay, in reply, was quite willing to accept marine fossils as coming from the Bed Marl. The fact of Estheria, a brackish or freshwater form, occurring in certain bands was in favour of his views; as he considered that at intervals the saltness of the water in such a lake as he had suggested must have varied. He could not accept the probability of oxide of iron having been deposited in a large sea-area to such an extent as to colour the sands. All rocks that could be proved to be of marine origin, even when they contained iron, were not stained red unless by infiltration from above. He pointed out that the old area of the Caspian was far larger than the lake in which he had suggested that the New Bed Marl had been deposited. If, as was more than probable, there had been during all geological time continental areas somewhat in the same positions as those of the present day, there must have been large areas of inland drainage in which some such deposits as those in question must of necessity have been formed.
[Plate XI.]
It is remarkable that so little is known of the skulls of the Wealden Dinosauria, the more so as their other remains have been procured in some abundance in the south-east of England and the Isle of Wight during the fifty years which have elapsed since Dr. Mantell's discovery of an Iguanodon's tooth in the quarry near Cuckfield. Hypsilophodon Foxii is, I believe, the only one the form and a great part
