Notices of Memoirs — Carboniferous Zones. 521 



break down to the present day the continuity is so marked that we 

 may conclude that the present face of the earth is merely the last 

 in a long succession in the Tertiary Period. 



II. The Carboniferous Limestone Zones op N.E. Lancashire. By 

 Albert Wilmore, D.Sc. 



rnHE sequence is well seen in the neighbourhood of Clitheroe, 

 JL where numerous quarries have been opened up. The lowest 

 beds exposed are near Chatburn Mill, and are dark, thinly-bedded 

 limestones with calcareous shale partings. Fossils are very scarce. 

 There is a great thickness of these almost unfossiliferous beds, the top 

 parts of which are dolomitic. 



Bold Venture Quarry, Horrocksford Quarry, and several other 

 exposures show beds in probably lower zone C, with numerous small 

 Zaphrentids (chiefly Zaphrentis omaliusi, with the variety ambigua of 

 Mr. R. G. Carruthers very common). Higher parts of these beds 

 contain Caninia cylindrica, which has been found at Brungerley 

 Bridge, in Bold Venture Quarry, at Pimlico, and at Downham. This 

 species is not so common or well developed as in beds farther east, 

 towards Hellifield and district. Among the Brachiopods are Chonetes 

 comoides, Orthotetes crenistria, etc. Large Gasteropods such as 

 Euomphalus pentangulatus and Bellerophon cornuarietis are common. 

 Conocardium hibernicum is a characteristic Lamellibranch. 



Above these beds come the lowest beds with Productus sub-lcevis t 

 and the Knoll beds of Goplaw, lower part of Worsaw, etc. Here are 

 the typical zone C, knolls with numerous Brachiopods, the Gasteropods 

 mentioned above, but few Corals. Amplexus coralloides is, however, 

 common and Michelinia sp. 



Above these are well-bedded crinoidal limestones leading up to the 

 knolls of Salt Hill, Bellman Park, "Worsaw, etc., which are probably 

 in the upper C or lower S of Dr. Vaughan's zonal scheme. These 

 beds contain a rich Brachiopod fauna, quite distinct, however, from 

 that of Elbolton. Whilst Productus pustulosus, Pr. semireticularis, 

 Spirifer striatus, etc., are quite common, one never finds Pr. striatus, 

 Pr. martini, and other P. forms so common in those eastern knolls. 



A fairly rich coral fauna has lately been discovered in these higher 

 Clitheroe knolls ; it has not yet been worked out, however. There is 

 probably an unconformity at this level, and then there succeeds a 

 great thickness of shales with limestones, with few fossils. These 

 would appear to be on the same horizon as the richly fossiliferous 

 beds of Elbolton. Above these shales with limestones come the 

 Pendleside limestones, black limestones with cherts, and with 

 irregular bands of moi*e fossiliferous limestone. The Ravensholme 

 limestone appears to be similar and to contain some of the same fauna 

 as the highest limestone at Cracoe and the limestone of the railway 

 quarry atRylstone described by the writer. 



The Bowland shales succeed these beds, and lead up to the Millstone 

 Grit series. A map was exhibited on which some of these generaliza- 

 tions were shown. 



