412 MR. G. C. CRICK OX CARBONIFEROUS CEPHALOPODA [Aug. I9II T 



Gl. diadema), Orthoceras JconincHanum and 0. obtusum l ; though it 

 should be mentioned that all these forms, excepting 0. JconincJci- 

 anum, have been recorded either as occurring in the Lower Coal- 

 Measures or as passing up into the grits and Lower Coal-Measures. 

 The two forms which seem to indicate a somewhat lower horizon 

 than the ' Pendleside Group ' are Glyphioceras crenistria and Gl. 

 sphcericum, species characterizing the Carboniferous Limestone. 

 These, as already said, are stated to have been found at Bonhay 

 . Road (Yicary), and it is to observed that their mode of preserva- 

 tion differs from that of the rest of the fossils in that they are 

 pyritized, more or less uncompressed, and exhibit the suture- 

 lines. 



Respecting the ' Pendleside Series,' which in the Midlands is 

 stated to consist of about 1000 feet of black shales, resting on the 

 top of the massif of Carboniferous Limestone, Dr. Hind states that " 



' The Pendleside Series thins out rapidly to the south of Derbyshire, and is 

 only represented by a few feet in Leicestershire and Shropshire. Still further 

 south, I consider that the Bishopton Beds in South Wales and the Lower Culm 

 Series of Devonshire are the hoinotaxial equivalents of the Pendleside Series 

 of the Midlands. The lithological similarity of the series in Devonshire, and 

 especially the peculiar fauna of the Lower Culm, agree so markedly with the 

 characters of the Pendleside Series that one cannot be blind to the evidence. 

 Moreover, the Lower Culm is overlaid by grit beds, which are in turn over- 

 laid by soft shales with bullions at Instow containing : — 



Pterinopecten papyraceus. j Gastrioceras carbonarium. 



Posidoniella lesvis. Dimorphoceras gilbert soni. 



Gastrioceras listeri. Orthoceras sp. 



a fauna which is abundant in the Lower Coal-Measures of Lancashire and the 

 Midlands ; and at Robert's Quarry, near Bideford, immediately above beds 

 containing a fairly rich and typical Coal-Measure flora, is a band of fawn- 

 coloured, iron-stained shale with Carbonicola acuta, a characteristic shell of 

 the middle portion of the Coal-Measures, so that one may safely infer that the 

 Culm-Measures of Devonshire represent the Carboniferous sequence of the 

 Midlands, minus the massif of Carboniferous Limestone.' 



During the visit of the Geologists' Association to North Devon at 

 Easter 1910, Dr. Wheelton Hind gave a lecture on the correlation 

 of the Carboniferous rocks in North Devon with those in other 

 areas. The report 3 of the lecture states that the species which 

 Dr. Hind regards as the most important zonal forms, and, taken 

 together, form the faunal sequence which characterizes the lower 

 part of the Upper Carboniferous rocks, are : — 



Zone of Gastrioceras listeri 4 Millstone Grit. 



„ Glyjphioceras bilingue i Millstone Grit. 



„ Glyphioceras spirale and Gl. diadema .. 1 



,, Glyphioceras reticulatum (maximum) l-p -,, ., ~ . 



,, Nomismoceras rotiforme and Posidonomya j 

 becheri , J 



1 This species is not recorded by Dr. Wheelton Hind from the ' Pendleside 

 Series' ; but the type-specimen (see antea, p. 410) came from High-Green Wood, 

 near Hebden Bridge, and we have also seen the species from the ' Pendleside 

 Series ' of Hebden Bridge. 



2 ' Monogr. Brit. Carb. Lamell.' (Pal. Soc.) vol. ii, pt. 3 (1904) p. 174. 



3 Proc. Geol. Assoc, vol. xxi (1910) pp. 463-64. 



4 By the list given above (p. 411) it will be seen that both these forms were 

 included by Dr. Hind & Mr. Howe in the fauna of the ' Pendleside Group.' 



