42 
THE GEOLOGIST. 
acknowledgements are recorded in my larger work, which, when 
complete, will compose a quarto volume, illustrated by some fifty or 
more plates. I may likewise mention that, with very few exceptions, 
I have had the gi^eat 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 t3^e. 
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 commeix^ed my researches among the British 
Carboniferous Brachiopoda, some two hundred and fifty &o-termed 
species had been recorded ; but after a most searcliing 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 Yorksliire," 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 
Avisli ; and it is very possible and probable that the rocks of that 
island have afibrded 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 gTeat 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 haA^e not been able, as abeady stated, to identify 
more than about seventy-three. Mr. Kelly's Catalogue comprises a 
gTeat number of Siluinan and Devonian species not known to me to 
occur in any Carboniferous rocks hitherto examined; and I may 
T^dthout hesitation assert that the larger number are, at any rate, 
due to 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. 
* " Or the Localities of Fossils of the Carboniferous Limestone of L'eland :" 
Journal of the Geological Society of Dublin : 1855. 
