203 



justifies the fullest confidence in the accuiacy of any facts stated upon 

 his authority. Mr. Moore, on the other hand, denied the presence of 

 the Rhjetic beds in the section referred to, but admitted that the 

 occurrence of the Rhsetic Oyster fOstrea interstriata) would afibrd 

 strong primA fade evidence of the fact, should its presence there be 

 proved. In order to test the matter, Messrs. Moorb and Tomes met at 

 the Bridgend section, and there found 0. interstriata in company with 

 G. incurva, as Mr. Tomes had stated, but under circumstances which led 

 to the conclusion that the Ostrea was out of its true horizon— an emigrant, 

 not a native— derived from the underlying beds, where it was found 

 "growing in profusion on a floor of Mountain Limestone, from which the 

 waves had removed the superincumbent Lias." But this is not all: "A 

 Gryphite was picked up, on which were growing no fewer than six small 

 specimens of 0. interstriata," which, in the words of Mr. Tomes, "disposes 

 of the whole question:"— "at this locaHty, at any rate, the species are 

 coeval." A most remarkable and instructive discoveiy is this; one 

 which shews with how jealous an eye we should scrutinize the most 

 minute facts in connexion with geologic enquiry; while at the same 

 time it should prompt us to exercise the utmost caution in laying down 

 dogmatic formulas for the government of such a science, seeing that the 

 occurrence of an Oystqr out of its place may suffice to raise doubts 

 respecting the presence of an entire epoch of creation. 



It is clear that from henceforth Ostrea interstriata can no longer be 

 looked upon as typical of the White Lias; but like so many border forms, 

 which are common to two adjoining but wholly distinct formations, is 

 characteristic of neither. Its place is ti-uly and naturally in the White 

 Lias- but we have here incontrovertible evidence of its having crossed 

 the boundary of the Rhsetic beds into those of the Lower Lias, where, 

 however, it would seem to have encountered circumstances no longer 

 favourable to its growth and extension, and, after a short struggle, to 

 have become extinct. 



On the return voyage by the canal, Mr. Jones read a paper on the 

 Reptilia of the county, and exhibited a fine pair of horns from the bed 

 of the Severn, which Professor Owen has decided to belong to £o8 

 primigenius. There is reason to beUeve that the horns in question have 

 been derived from extensive peat deposits, which have been traced for 

 great distances along both banks of the Severn, containing trees and 

 well-preserved leaves, fruits, and roots, in all respects similar to those 

 which characterise the submerged forests found in so many localities 

 around our coasts. Antlers of large size have been procured from thence. 



