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JOURNAL OF CONCHOLOGY. 



Vol. i6. JUNE, 1921. No. 6. 



CENSUS OF THE DISTRIBUTION OF BRITISH LAND 

 AND FRESHWATER MOLLUSCA. 



By the late W. DENISON ROEBUCK. 



Introduction. 

 From the printed records of the Society it is not very clear when 

 Roebuck began a systematic record of the distribution of British 

 land and freshwater moUusca, but he used to reckon himself (e.g. 

 Journal, v, p. 200 ; vi, 314) that the census began in 1877, and the 

 first entry in the books was made on 25th October, 1876. They 

 show plenty of fresh entries up to the end of 19 18, so that the data 

 summarised here are the product of forty-two years' work. For the 

 first three years or so the project was practically confined to York- 

 shire, but at the sixty-fifth meeting of the Society, held in Leeds in 

 the early part of 1881, Roebuck read a paper {^Journal, iii, p. 138) 

 on a " proposed system of conchological locality records," in which 

 he advocated that " the Conchological Society should commence a 

 system of recording the localities of British moUusca," it being " an 

 indispensable requirement that everv record be accompanied by a 

 voucher specimen," and H. C. Watson's arrangement of county 

 areas being used — the whole in imitation of the methods of the 

 Botanical Record Club. The plan was presumably approved by the 

 Society, for at the annual meeting in December, 1882, Roebuck was 

 definitely appointed " Recorder of the Conchological Society," and 

 a year later reported that 2,965 records had been added during the 

 year, bringing the total to 5,636. Progress was annually reported 

 each year till 1891, when a total of 31,405 for fourteen years' work 

 is noted {Journal, vii, p. 16). Roebuck continued to be official 

 recorder till 1895, when E. Collier succeeded him, to be replaced 

 the following year by T. Rogers for four years, followed by L. E. 

 Adams (1900-1903), C. Oldham (1903-1906), and F. Taylor (1907- 

 1910) ; in 1911 Roebuck resumed the appointment, and continued 



The expenses of publication have lieen partly defrayed by a grant from the Royal -Society. 



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