Oeological Society, 451 



forming the southern end of the Pennine anticline, with a few 

 small outliers. The base of the Limestone is not shown, and the 

 whole series exposed constitutes a greatly-expanded development 

 of the uppermost zone of the typical Avonian succession of the 

 (South- Western Province, namely, the Dihunoj)hylhwi-Zone. The 

 most extensive section — that along the Midland llailway, between 

 Longstone and iJuxtou — shows a thickness of about 1500 feet. 

 Three subzonal divisions are distinguished, as follows : — 



D3. Subzono of Cyathaxonia nishiana : represented in the South-Western 

 Province bj horizon e and the lower part of the Millstone Grit. 



D^. Subzone of Lonsdalia floriformis : correlated with the Upper 

 Bibtmophyllum-Zone (D^) of the Soutb-West. 



D,. Subzone of Bihnnophyllum 9 : correlated with the Lower Dihuno- 

 phyllum-Zoi\Q (Dj) of the South -West. 



An abnormal development of the Lonsd((lia-s,\ihzonG, consisting 

 of richly-fossiliferous brachiopod-beds, in which the typical coral- 

 fauna has very little representation, forms a conspicuous local 

 feature in various parts of the western half of the area. The 

 passage-beds between the Carboniferous Limestone and the Pendle- 

 side Series are included in the Cijathaxonia-9,n\)7.o\ic. Locally, these 

 passage-beds attain a thick development. A local unconformity 

 between the Carboniferous Limestone and the Pendleside Series, indi- 

 cating contemporaneous elevation and erosion, occurs in the eastern 

 part of the area. A close general similarity exists between the 

 Dihunophiillnm-ZoxiQ of the Midland area and that of North Wales. 

 These two areas should be regarded as constituting a Midland 

 Province. A comparison of the Dibunophyllum-zoiio of the Midland 

 with that of the South-Westcrn Province brings out the following 

 more important differences : — (a) The brachiopod-fauna of the 

 Lonsdalia-snhy.on.e of the Midland Province is considerably richer 

 than tliat of the ecjuivalent part of the South- Western sequence. 

 (h) The Cijatha.vonia-suhzone of the Midland Province, which attains 

 a maximum development in Derbyshire and North Staffordshire, is 

 practicallj^ undeveloped in the South- Western Province. 



The paper concludes with a description of certain corals and 

 brachiopods from the Midland area, some species and varieties 

 being new. 



2. ' Brachiopod Homoeomorphy : '' /Sj^trifer glaber".'' By S. S. 

 Buckman, F.G.S. 



The smooth, catagenetic, stage of shells may have been attained 

 by the loss of different distinctive features, pointing to ])olygcnetic 

 origins. The series of shells figured ])y JJavidson as S/nrifcra 

 cjlahra do not all agree in being smooth ; some are radially costate, 

 some have a pronounced mesial fold, others hardly any, some are 

 very transverse, others are narrow. There is good evidence that 

 several of the forms ranged under this species are lleticularia? 

 (^f'Coy), more or lees smooth. Thus Sp. obtiisus, regarded by 

 Davidson as a synonym of Sp. tjlabra, shows faint reticulution, has 



