Mr. A. Robertson on the Freshwater Fossils of Brora. 71 



Pinna sulcifera. Terebratula biplicata. 



Perna mulleti. elegans. 



Gervillia anceps. sella. 



aliformis. Auricula incrassata. 



Avicula ? Natica. 



Pholadomya Prevosti, Turritella laevigata. 



rhomboidalis. Dupiniana. 



Lima elegans ? Rostellaria ? 



Pecten interstriatus. ? 



Hinnites Leymerii. Nautilus pseudo-elegans. 

 Exogyra sinuata, var. N 



subsinuata. 



Ostrea Leymerii. Pycnodus 



There is still direct evidence in the Isle of Portland that a part of 

 the south of England rose into dry land at the close of the oolitic 

 aera : and other considerations make it very probable that at that 

 time the extent of dry land in the northern latitudes was very con- 

 siderable. The range of the Neocomian deposits along the south of 

 Europe shows the amount of submersion, next after the oolitic epoch, 

 and we see in the Boulonnais, in the Pays de Bray, in the Paris 

 basin, Franch Cerate, Neufchatel, and part of Germany, how very 

 close the upper marine Neocomian beds approach to our own fresh- 

 water or tertiary Wealden : so that consistently with the views of 

 the continental geologists, we seem to have ascertained some inter- 

 esting points in the physical geography of a part of the surface of 

 the earth during the secondary period ; such as the direction from 

 which the waters of the vast Wealden stream flowed, and the line 

 where (approximately at least) they joined those of the sea. No 

 one who has either traced the cretaceous series in the range along 

 the southern portion of England, has seen it abroad, or studied the 

 numerous fossil remains which the formation contains, together with 

 their geographical range, can entertain the least doubt but that the 

 sea which deposited it was brought from the south northwards by a 

 gradual process of overlap. For this reason it is that the cretaceous 

 series of the continent, and of the south of Europe in particular, is so 

 much more fully developed than our own ; and it becomes of interest 

 to ascertain at what precise period it was that its waters reached our 

 latitudes ; in other words, how much of the series is represented here. 

 The groups of this country must cease to be the measure and type 

 of the cretaceous epoch, of which they only represent a part. 



" Notice of the occurrence of Beds containing Freshwater Fossils 

 in the Oolitic Coal-field of Brora, Sutherlandshire." By Alexander 

 Robertson, Esq., F.G.S. 



Among the reefs of shale and coal opposite the old salt-pans at 

 Brora, Mr. Robertson has discovered two beds abounding in Cyclas 

 and other freshwater fossils, approachable only at low water. The 

 rise of the tide on the occasion of his visit to the locality, prevented 

 a minute examination of their relations. Their position was however 

 satisfactorily made out, and is, in the descending order, as follows : — 



a. Beds of calcareous sandstone, considered by Mr. Phillips to re- 



