THE GEOLOGIST. 
FEBRUARY, 1861. 
ON BRITISH CARBONIFEROUS BRACHIOPODA. 
By Thomas Davidson, Esq., F.R.S., F.G.S., etc 
Four years have elapsed since I first commenced my researches 
among the Carboniferous Brachiopoda of Great Britain ; and I should 
certainly by this time have completed my task, had not the unfortu- 
nate delay in the publication of the last two or three volumes of the 
Palaeontographical Society induced me to undertake other work which 
would not require to lie printed and unpublished for upwards of one 
year and a half My monogTaph cannot, consequently, be completed 
or entirely published for some time to come, perhaps a year or more ; 
but as my researches in connection -with the subject are almost ended, 
since the whole series of species at present known have been as 
carefully examined as my means and materials would permit, it may, 
perhaps, be as well that I should at once expose the results of my 
laborious enquiry, in the hope that by so doing some fm'ther assistance 
and advice may be proffered ; which might enable me to make the 
monograph still more complete, and at the same time admit of my 
correcting in the concluding pages those unavoidable mistakes which 
have been commited during the interval which has elapsed since the 
commencement of its publication. 
It may be thought by some while perusing the accompanying cata- 
logue that the work to be gone through was but small in comparison 
with the time employed, but such would be an erroneous assumption, 
and a sad return to the numerous friends in England, Scotland, and 
Ireland, who have so zealously afforded their valuable and valued 
assistance, by incessantly ransacking the country in order to obtain 
every possible specimen that might assist and tend to complete the 
history of British Carboniferous species. Thousands and thousands 
of specimens have been assembled and transmitted to me by rail and 
post ; and if I refrain from mentioning names it is because my full 
VOL. IV. F 
