11 



John Hoptown Forbes, Esq. of Ely Place, were elected Fellows of 

 this Society. 



The reading of a paper was concluded, " On the coal-field of 

 Brora in Sutherlandshire, and some other stratified deposits in the 

 north of Scotland;" by R. I. Murchison, Esq. Sec. G.S. F.R.S. 



The Brora coal-field forms a part of the deposits, which on the 

 S.E. coast of Sutherlandshire occupy a tract of about twenty miles 

 in length, from Golspie to the Ord of Caithness ; and three miles in 

 its greatest breadth: — divided into the valleys of Brora, Loth, and 

 Navidale, by the successive advance to the coast of portions of the 

 adjoining mountain range which bounds them on the W. and N.W. 

 The first of these valleys is flanked on the S.W. by hills of red-con- 

 glomerate ; which pass inland on the N.E. of Loch Brora, and give 

 place to an unstratified granitic rock that forms the remainder of 

 the mountainous boundary. 



With a view to the comparison of the strata at Brora with those 

 of England, the author had previously examined the N.E. coast of 

 Yorkshire, from Filey-Bridge to Whitby, comprising the coal-field 

 of the Eastern Moorlands above the lias. 



The highest beds at Brora consist of a white quartzose sandstone, 

 partially overlaid by a fissile limestone, containing many fossils, — 

 the greater number of which have been identified with those of the 

 calcareous grit beneath the coral rag; — and along with these Mr. 

 Sowerby has discovered several new species. The next beds, in a 

 descending order, are obscured, in the interior, by the diluvium which 

 is generally spread over the surface of these valleys, but are ex- 

 posed on other places on the coast ; and they consist of shale with 

 the fossils of the Oxford clay, overlying a limestone resembling 

 Cornbrash and Forest Marble, the latter associated with calciferous 

 grit. To these succeed sandstone, and shale containing belemnites 

 and ammonites, through which the shaft of the present coal-pit is 

 sunk, to the depth of near 80 yards below the level of the river Brora. 

 The principal bed of coal is 3 feet 5 inches in thickness, and the roof 

 is a sandy calcareous mixture, of fossil shells and a compressed as- 

 semblage of leaves and stems of plants, passing into the coal itself. 

 The fossils of this and the superior beds are identical for the greater 

 part, with those which occur in the strata above the coal in the E. of 

 Yorkshire : and of the whole number of species collected by the au- 

 thor, amounting nearly to fifty, two-thirds are well known fossils of 

 the oolite ; — the remainder belonging to new species represented in 

 the last numbers of the Mineral Conchology. The plant of which 

 the Brora coal appears to have been formed, is identical with one of 

 the most characteristic vegetables of the Yorkshire coast, but differs 

 essentially from any of the plants found in the coal measures be- 

 neath the new-red-sandstone : — It has been formed into a new genus 

 by Mr Konig, and is described by him in the present memoir, under 

 the name of Oncylogonatum. 



The author, therefore, considers the Brora coal, from its asso- 

 ciated shells and plants, as the equivalent of that of the Eastern 

 Moorlands of Yorkshire. 



At Loth, Helmsdale, and Navidale? shale and sandstone overlie 



