APPENDIX AND CONCLUSION. 



Five years have elapsed since I first commenced my researches among the Carboniferous 

 Brachiopoda in connexion with this Monograph, and although the time employed may be 

 thought great, it must be remembered, in justice to the many gentlemen who have so 

 zealously afforded me their valuable assistance, that the country and strata has during 

 that interval been continually searched in order to obtain every specimen that might 

 tend to complete the history of our species. 



During this lengthened investigation, a vast number of specimens have turned up, 

 and been attentively studied, so that it will be necessary in these supplementary pages to 

 propose some few alterations to the published portions of the work, as well as to add 

 further observations and new species which, having become subsequently known, could 

 not be included in the regular succession of described species. 



At the time I commenced my researches, about 260 so-termed British carboniferous 

 species of Brachiopoda had been recorded by different palaeontologists, but after a most 

 searching investigation, I could not conscientiously admit more than about 100 of these, and 

 in order to arrive at such a reduction, no small labour was required, nor was I unmindful of 

 the danger Palaeontologists should guard against in the breaking down of species, Avhich 

 if injudiciously done, would be as great an evil as that of uselessly multiplying them. 1 



1 It may be as well to mention that in the second and improved edition of Prof. Morris's ' Catalogue,' 

 published in 1854, 193 species are recorded, but of these about 93 only are retained on my lists. 



In 1836, Prof. Phillips enumerated 100 species as having been found in England, of which about 

 52 are retained. 



In his ' Synopsis of the Carboniferous Fossils of Ireland,' published in 1844, Prof. M'Coy described 

 230 so-termed species of Carboniferous Brachiopoda stated to have been found in Ireland, but he figured 

 only 62. Of the 230, not more than 70 appear to me good species, about 61 are Devonian or Silurian 

 names not known or proved to have been found in true Irish carboniferous strata, and about 117 are 

 either synonyms, or are due to incorrect determinations. 



In his memoir ' On the Localities of Fossils of the Carboniferous Limestone of Ireland,' Mr. Kelly 

 enumerates no less than 240 so-termed Irish species ! the catalogue comprising the 230 described in the 

 ' Synopsis,' and some others from Portlock's 'Report on the Geology of Londonderry, &c. ;' and if we add 

 a few more subsequently discovered, about 250 species ! would be put down to Ireland, while my most 



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