667 



head road, but the pebbles are there sometimes a foot in 

 diameter. 



2. Thin bed of the same sandstone. 



3. A thick deposit of red marl, containing numerous angular and 



water-worn pebbles, interspersed thickly with shells appa- 

 rently belonging to the Ludlow rocks. This marl forms a 

 considerable part of Ffernant Dingle ; but it alternates with 

 a compact marl, and is sometimes speckled green or yellow. 

 The beds dip at a high angle to the north. Similar pebbles 

 are found on the top of the limestone precipices, and beyond 

 them on the beach. 



4. Compact, hard, arenaceous conglomerate, composed of pebbles 



more or less rounded, of liver-coloured and green micaceous 

 shelly sandstone, also of pebbles of quartz, and the reddish 

 subjacent limestone. 



5. Thin beds of compact reddish limestone containing few organic 



remains. It passes occasionally into a calcareous sandstone. 



6. Near the lower end of the dingle, the limestone rests on a bed 



of very fine blue clay. 



7. Blue clay-slate, finely grained, slightly micaceous, and containing 



occasionally a layer of small shells. It sometimes presents 

 obscure indications of vertical cleavage. This rock constitutes 

 the whole of the southern portion of the dingle, and in one 

 place is traversed by a fault. 

 The rill in Ffernant dingle flows into Melin y Person brook. The 

 red marly conglomerate is there succeeded, on the south, by alluvium 

 containing slate pebbles. Above the village of Bettws Abergele the 

 slate rocks occur, but are greatly contorted; and on the height a little 

 further south, and to the east of the road, is a hard finely grained rock 

 inclosing joints of small encrinites. Still further south this rock alter- 

 nates with beds of breccia, containing encrinital and other organic 

 remains, the imbedded angular fragments consisting of glossy clay- 

 slate. A little south of this quarry, towards Garthewin, the non- 

 fissile blue slate again occurs, and the author found in it abundance 

 of small fragments of encrinites, with univalves and bivalves. These 

 fossils occurred apparently in layers, but were much decomposed. 

 Similar remains were noticed, by Mr. Bowman, in the debris of the 

 lead mines at the Bronhaylog, to the north-east of Garthewin. 



The paper was accompanied bya list of fossils preparedby Mr. James 

 de Carle Sowerby, including the following species which have been 

 found by Mr.Murchison in the Ludlow Rocks elsewhere : Leptcenalata, 

 Terebratida nucula, T. pulchra, T. navicula, Conularia quadrisulcata, 

 Atrypa affinis, Orthis orbicularis, Cypricardia cymbceformis, var., JVm- 

 cula ovalis, Euomphalus funatus, Orthoceras striatum, Avicula re- 

 trojlexa, and Pleurotoma corallii. 



A notice " On the Occurrence of Wealden strata at Linksfield, near 

 Elgin ; on the Remains of Fishes in the Old Red Sandstone of that 

 neighbourhood ; and on raised beaches along the adjacent coast ;" by 

 J. Malcolmson, Esq., F.G.S., was then read. 



