KORRtirK MKMOKIAi, XUMRRR. I67 



furtlier delayed. In 191 7 a special fund to provide for publication 

 was successfully inaugurated, and Roebuck began a revision of the 

 records, but for various reasons no further progress could be made. 

 On 15th February, 1919, Roebuck died, leaving his books and 

 papers in such good order that the reduction of his data to their 

 present form has not been difficult, though lack of familiarity with 

 his plans has unduly delayed, and doubtless maimed, their presenta- 

 tion. In accordance with his intention, the whole of the records 

 from the beginning have been examined and re-catalogued for this 

 edition, which is therefore something more than the version of 1902 

 brought up-to-date. 



The census consists entirely of records based on actual specimens of 

 snails and slugs 7vhich have been seen and identified by the Society's 

 referees ; no records have been admitted unless voucher specimens have 

 been authenticated in this zvay. The uniformity of truth — or error as 

 the case may be — is thus considerable. But it is not absolute ; it 

 could not have been in any human scheme and the records are not 

 all of equal vahdity. In the great majority of cases the specimens 

 have been submitted to the referees through the recorder by the 

 actual collectors, mostly at the time. In other cases they have reached 

 him through collections, public or private, and among these is a 

 certain number of museum records which are less satisfactory. It lias 

 been difficult to decide in some cases whether museum specimens 

 should be regarded as good records or not : generally speaking 

 importance has been attached to the presence or absence of details 

 of locality and collector, to prima facie probability and to collateral 

 evidence. Thus " Pupa cylindracea, Caerlaverock Castle, Dumfries- 

 shire ; R. Rimmer, 6th Sept., 1S89," in the Edinburgh Museum raises 

 no reasonable doubts. Ena nwntana in the Alder Collection at 

 Newcastle labelled " Whipstead, Suffolk," would be suspicious were it 

 not known {Journal, xi, 337) that the species has been collected in 

 more than one place in West Suffolk. Contrariwise, a specimen in 

 the Parfitt Collection at Exeter, labelled " Plymouth " is not reckoned 

 as a valid record in the absence of any other evidence that the species 

 has occurred in such an unlikely neighbourhood. Nor can Clausilia 

 cravenensis from " Suffolk " in the National Museum of Wales be 

 regarded as satisfactory. These museum records form a very small 

 proportion of the whole and in view of these considerations they have 

 been catalogued separately and when they are of importance they are 

 specially noted. In the same way improbable and ill-defined localities 

 attached to specimens in private collections have been regarded as 

 suspicious in the absence of some extraneous confirmation ; where 

 possible they have been referred to the original collectors. In these 

 ways therefore we get two categories of records, those which seem 



