42 



THE GEOLOGIST. 



acknowledgements are recorded in my larger work, which, when 

 complete, will compose a qnarto volume, illustrated by some fifty or 

 more plates. I may likewise mention that, with very few exceptions, 

 I have had the great advantage of obtaining the loan of the original 

 specimens from which each species had been first described, so that 

 my comparisons have generally commenced with the type. 



As a great many so-termed species have been rejected, it will be 

 desirable to enter upon some few explanatory details. 



At the time when I commenced my researches among the British 

 Carboniferous Brachiopoda, some two hundred and fifty so-termed 

 species had been recorded ; but after a most searching investigation, 

 I could not conscientiously make out more than about one hundred 

 and eight ; and even of this number some few should be located 

 among the varieties, so that the determined species would not, at the 

 present time, in all probability exceed about a hundred. In the second 

 and improved edition of Prof. Morris's " Catalogue," published in 

 1854, one hundred and ninety three species are recorded, but of 

 these about eighty-one only are retained in our lists. 



It would be impossible in . this short paper to enter into many 

 statistical details ; but we may mention that in 1836 Prof. Phillips 

 enumerated about one hundred species, as having been found in 

 England, and of which fifty-two are by us retained. Since the 

 period of the publication of the " Geology of Yorkshire," many more 

 species have been discovered, so that about ninety-seven are pro- 

 visionally catalogued. The species from Scotland haye been care- 

 fully examined, and from forty-nine to fifty retained. The Irish 

 species have not, perhaps, been so completely studied as we might 

 wish ; and it is very possible and probable that the rocks of that 

 island have afforded some few more than the seventy-three here 

 admitted. 



In 1844, Prof. M'Coy described two hundred and twenty-nine 

 species, stated by him to have been found in Ireland, but figured only 

 about sixty ; and to this number several others were subsequently 

 added by other naturalists, so that Mr. Kelly's Catalogue* comprises 

 no less than two hundred and thirty-seven ! If we compare Mr. 

 Kelly's lists with the one here given a very great difference will be 

 perceived ; for notwithstanding all my good will and the liberal 

 assistance of many Irish geologists, who assembled for my use every 

 possible species, I have not been able, as already stated, to identify- 

 more bhari about seventy-three. Mr. Kelly's Catalogue comprises a 

 great number of Silurian pd Devonian species not known to me to 

 occur in any Carboniferous rocks hitherto examined ; and I may 

 without hesitation assert that the larger number are. at any rate, 

 due bo incorrect identification; for the examination of many of the 

 original specimens in Sir Richard Griffith's collections have convinced 

 Prof, de Koninck, Mr. Salter, and myself of this important fact. 



* " On the Localities of Fossils of the Carboniferous Limestone of Ireland :" 

 Journal of the Geological Society of Dublin : 1855. 



