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 

 Paheonto graphical 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 would not require to lie printed and unpublished for upwards of one 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 monograph 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 further 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 



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