at Pounceford, in Sussex, 601 



America, &c, for example, to find the remains of large species 

 of Mammalia which frequent the banks of rivers, such as the 

 hippopotamus and rhinoceros in the former, the tapir in the 

 latter country, which we know are now annually carried down 

 and entombed in the deltas. 



" It is certainly a very startling proposition," observes 

 Lyell, in his invaluable Principles of Geology (iv. p. 235.), " to 

 suppose that a continent covered with vegetation, which had 

 its forests of palms and tree-ferns, and its plants allied to the 

 dracsena and cycas, which was inhabited by large saurians, 

 and by birds, was nevertheless entirely devoid of land qua- 

 drupeds. If the proofs were confined to the Wealden, we 

 might hesitate to lay much stress on mere negative evidence, 

 since extensive deposits of the Eocene period, such as the 

 London clay, have as yet yielded no mammiferous fossils, and 

 the coal strata of Great Britain, after having been studied for 

 so many years, are only now beginning to produce the bones 

 of saurians. But when we find the same general absence of 

 mammalia in strata of the oolitic and liassic eras, we can hardly 

 refuse to admit that the highest order of quadrupeds was very 

 feebly represented in those ages when the small didelphis of 

 Stonesfield was entombed. Some of the bones, indeed, col- 

 lected by Dr. Buckland from the oolitic series have been pro- 

 nounced by Cuvier to be cetaceous ; but that naturalist has 

 himself remarked how closely the vertebrae of the larger rep- 

 tiles resemble those of certain dolphins ; so that it is highly 

 desirable that the fossils alluded to should be examined with 

 great care." 



We may therefore conclude that, during the periods of the 

 Wealden, the oolite, and the lias, there was, as Lyell observes, 

 " a large developement of the reptilia, at the expense, as it 

 were, of the cetaceous and terrestial mammalia." (Lyell, Prin- 

 ciples of Geology, iv. p. 236.) 



While the species and genera of Testacea found in the cre- 

 taceous beds are very abundant, in the green-sand group alone 

 (including the upper and Shanklin, or lower, green-sands, and 

 the gault) 49 genera, 86 species, and almost exclusively 

 marine ; those found in the Wealden, on the other hand, are 

 much fewer, 10 genera and 30 species only having been 

 hitherto determined, although the individuals are abundant to 

 profusion, and belong, by far the greater part, to fresh water. 

 Notwithstanding these remarkable facts, there are no indi- 

 cations of disturbance, with the exception of part of the coun- 

 try adjoining the strata hereafter described, which is very 

 much dislocated, affording many faults, or " horses " as the 



Vol. VIII. — No. 55. uu 



