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BRITISH DEVONIAN BRACHIOPODA. 



in part at least, the ' Coomhola series' of Jukes, which stratigraphically would belong to 

 the Carboniferous system, but which contain a great majority of Carboniferous species 

 with a very few hitherto known only as Devonian. 



The fossils occur abundantly in these lower shales, slates, and sandy rocks in the 

 condition of imperfect distorted internal casts and impressions, and are often so obscure 

 as to render their specific determination impossible, or at least very uncertain. We are, 

 however, sometimes able to reproduce the shell, with its natural shape and character, by 

 pressing a piece of softened gutta-percha into the impressions the shell has left in the 

 rock ; and I must here observe, that the aspect of the rock and its accompanying fossils is 

 quite similar to what we find in North Devon, viz., the Marwood and Pilton group. I 

 am moreover indebted to Mr. Jukes for having forwarded for my inspection some hundred 

 specimens collected from those beds by the Geological Survey of Ireland. 1 



In his paper on the " Upper Old Red Sandstone, &c," published in the ' Journal of 

 the Geological Society' (Nov. 1863), Mr. Salter considers the Carboniferous Slate of 

 Ireland to overlie and to be distinct from the Coomhola series, which last he looks 

 upon as equivalent to the Marwood series of Devonshire, referring it to the Upper 

 Devonian and not to the Carboniferous series. It may therefore be more con- 

 venient for the sake of reference and comparison to arrange into three columns those 

 species of Brachiopoda which I have found, by personal examination, to occur in the 

 Carboniferous Shales, ' Coomhola series' of the county of Cork, and the Marwood and 

 Pilton beds of Devonshire and East Somerset. It will not, however, be necessary to 

 mention every species that occur in true and well-known Carboniferous Slates, as these will 

 be found enumerated in the Monograph that treats of that formation, but only to note 

 down those forms which occur likewise in the Coomhola and the Marwood series. We 

 will take no account at present of three or four very obscure and indeterminable fragments 

 which occur both in the Coomhola series and that of Marwood and Pilton, and 

 which may perhaps belong to different species from those we are about to enu- 

 merate. 



1 An allusion to these beds and fossils will be found in the footnote p. 42, &e., but a complete 

 account by Mr. Jukes, Mr. Baily, and myself, will be seen in the ' Memoirs of the Geological Survey of 

 Ireland,' or the 'Explanations to accompany Sheets 192 and 199 of the Geological Survey of 

 Ireland, illustrating part of the Counties of Cork and Kerry,' 18C4. 



