Dr. Wheelton Hind — Carboniferous Life- Zones. 65 



overlap. However correct those facts may ultimately be shown to 

 be in Belgium, there is in the Carboniferous beds of Great Britain 

 and Ireland nothing at all comparable to such exactness in the 

 vertical distribution of the faunas of the Carboniferous period ; 

 and if one fact is emphasized more than another, it is that many 

 species of Brachiopoda and Mollusca reappear again and again at 

 various horizons, and survived throughout the whole of the epoch. 



In Great Britain, Productiis giganteus is a fossil very frequently 

 met with, and of very wide vertical range. In the Pennine area it 

 is met with in all the limestones from the Great Scar to the Crow 

 Limestone, thus passing from the base of the Carboniferous Limestone 

 to the top of the Yoredale Series. In Northumberland, it occui's 

 with P. cora throughout the whole of the rocks grouped by the 

 officers of the Geological Survey as the Carbonaceous division ; and 

 in Scotland is characteristic of the limestones of the Carboniferous 

 Limestone Series, both upper, middle, and lower divisions. In 

 North Wales, P. giganteus j)asses from the Middle White Limestone 

 of Mr. Morton to the top of the series, accompanied in the Middle 

 White and Upper Grey Limestones by P. cora, which shell is found 

 alone in the lowest member (the Lower Brown Limestone) of the 

 series. In South Wales, Mr. Morton finds F. giganteus and F. cora 

 in the limestones of Gower, and Mr. Stoddart records both these 

 fossils in the Carboniferous Limestone of the Bristol district. 

 Mr. Stoddart published (Proc. Bristol Nat. Soc, new ser., vol. i, 

 1874-6, p. 318) a very careful account of the various beds of the 

 Lower Carboniferous Shales and Carboniferous Limestone of the 

 Bristol Coalfield, and the fossils contained in them. The majority 

 of the Mollusca and Brachiopoda are not, however, zonal forms, but 

 are found at various horizons in the Carboniferous series, both there 

 and elsewhere. M. Max Lohest, after going over the ground, 

 published a small pamphlet entitled " Sur le parallelisrae entre le 

 Calcaire Carbonifere des environs de Bristol et celui de la Belgique " 

 (Ann. Soc. Geol. Beige, torn, xxii, p. 7), in which he would establish 

 an almost complete identity between the Bristol and Belgian series. 

 This author recognizes zones indicated by A, B, D, E, F. 



A. Beds with Modiola Ilacadamii and Avictda Damnoniensis, which 

 correspond with those of Comblain au Pont. Mr. Stoddart, however, 

 pointed out the close connection of the fauna of these beds with that 

 contained in the Marwood, Coomhola, and Moyola beds. 



B. This bed is a red crinoidal bed, with Spirifer glaber, S. bisul- 

 catus (?), S. Tornacensis, and Spiriferina octoplicata, identified with 

 the lower part of the Tournaisian beds of Belgium ; but, with the 

 exception perhaps of Spirifer Tornacensis, all the other fossils are 

 found in the zone of Froductus giganteus, if not near Bristol, in the 

 topmost beds of the Carboniferous Limestone of Derbyshire and 

 Yorkshire. M. Lohest says : " Le base du terme B parait bien etre 

 I'equivalent de notre assise a Spirifer glaher ; les schistes du sommet 

 representant nos schistes a Spiriferina octoplicata " ; but in Great 

 Britain both these forms are most abundant in the upper part of the 

 Carboniferous Limestone. 



DECADE IV. VOL. T. NO. II. 5 



