Vol. 57.] PBNDLESIDE GROFP AT PENDLE HILL, ETC. 375- 



plentifully in a bed of shale belonging to the Posidonian schist- 

 series in 



' soft shale charged largely with sulphuret of iron, and in this we have pre- 

 served (converted into that sulphuret) the remains chiefly of cephalopods, 

 Goniatites, and Orthocerata,' ^ 



Position of the Posidonomi/ a-Schist^ in Ireland. 



Beds classed as Upper Limestone Shales are found in County 

 Dublin, and are exposed in the brooks of the Westown Demesne. 

 The fauna found in this series is tabulated as follows in the Memoir 

 of the Geological Survey of Ireland, Expl. Sheets 102 & 112 (1861),. 

 D. 60 :— 



Aviculopecten papyraceus. 

 A. variabilis. 



Fosidonoraya memhranacea. 

 Luniilicardium \_Foo till . 



Goniatites crenistria \^Gl. spimle]. 

 G. Listen. 



Orthoceras [Stein haueri], 

 Dithyrocaris sp. 



In the list of fossils Posidonomya Becheri is stated to be very 

 common in the Upper Limestone Shales at several localities. 



We have had the opportunity of examiniug the goniatites from this 

 locality, and are of opinion that those labelled Goniatites crenistria 

 should be more correctly referred to Glypliioceras sjnrnJe. Prole- 

 canites sp. and Nomismoceras sp. also occur on the same slabs. 

 Further, some of the specimens labelled Posidonomya memhranacea 

 seem to us to be large examples of Posidoniella Icevis. The fauna 

 is therefore completely characteristic of the Pendleside Group. 



The fauna of certain beds on Foynes Island, supposed to be 

 Lower Carboniferous, is interesting, and includes the following : — 



Glypkioceras reticulatum. 

 Gastrioceras Listeri (?) . 

 Nautilus tuherculatus. 



Posidonomya Becheri. 



Avicidopecten papyraceus. 



Orthoceras minimum, Baily, 

 Two gasteropods named by Eaily (Loxonema Galvani and Macrocheihis 

 inflatus) we consider to be identical with Thomas Brown's shells from Hebden 

 Brido-e (see p. 373), Macrocheilina Gihsoni and M. eleyans. 



The section given by the officers of the Geological Survey, Explan. 

 of Sheet 142 (1860), p. 8, shows the beds, supposed to be Lower 

 Coal-Measure, resting conformably and immediately upon the Upper 

 Limestone Series. They may, therefore, very well represent the 

 Upper Limestone- Shales or Pendleside Group, instead of Lower 

 Coal-Measures. The characteristic fauna found in them affords 

 strong presumptive evidence of this view. 



Summary of the Stratigraphical Evidence. 



We have shown by detailed sections that a group of beds, cha- 

 racterized by a definite fauna totally different from that of the 

 Mountain Limestone, exists in the form of a basin rapidly attenu- 

 ating till they finally cease, along a line drawn from the Isle of Man 

 to Harrogate. These beds have their maximum development in- 

 1 ' The Isle of Man ' 1848, p. 133. 



