l68 JOURNAL OF CONCHOI.OCV, VOI.. l6, NO. 6, JUNE, I92I. 



satisfactory and those which " require confirmation " ; the latter are 

 printed in italics in the table and often mentioned in the notes. 



All the older records of the smaller species of Pisidhim {i.e. all 

 except amniciim) are arranged under the five Jeffreysian species ; since 

 1913 a certain number have been identified according to the classifi- 

 cation of B. B. Woodward. All these have been discarded and 

 replaced by fresh records for which R. A. Phillips and A. W. Stelfox 

 have since 1918 acted jointly as referees on behalf of the Society. 

 Indications for fitting their nomenclature on to previous systems will 

 be found in t\\& Journal, xv, 235, 260, 289. 



There has been no systematic attempt to collect holocene records. 

 Incidentally a fair number have been included which are mentioned 

 in the notes when they appear to be of interest, but not in the table of 

 distribution. 



The list contains 163 species, 157 of which have been authenticated 

 for England, 127 for Wales, 115 for Scotland, and 126 for Ireland. 



COMITAL AND ViCE-COMITAL ArEAS. 



The areas adopted or the Census were those devised about 1845 by 

 H. C. Watson [Cybele Britannica, iv, (1859) 1 39 ff.) for England, Wales and 

 Scotland, and about 1858 by C. C. Babington (see Irish Nat. v, 29) for Ireland. 

 These corresponded to counties as they then existed, except that the larger counties 

 were sub-divided, some of the smaller united with a neighbour and all detached 

 portions included in the county by which they were surrounded. The political 

 boundaries have in some cases since been altered so that reference to old maps may 

 be necessary ; Watson used one published by the Useful Knowledge Society. Since 

 the last edition of the Census the Irish areas have been arranged so as to correspond 

 with those used by R. L. Praeger {Proc. Roy. Irish Acad. (3) vii (i9oi))and 

 shown on his map. There is unfortunately no corresponding map for the rest of 

 the British Isles. As may be imagined, the precise definition of dividing lines is a 

 large question, involving a great mass of topographical detail. Roebuck gave con- 

 siderable attention to it and was preparing to treat it on an ample scale. Here we 

 can reproduce only a short summary of the deviations of the boundaries of areas 

 from those of counties. 



1-2: Cornwall W. and E. ; road rom Truro through Ladock to St. Columb 

 and Wadebridge. 3-4 : Devon N. and S. ; along the watershed from the 

 Tamar at Leigh Barton, about midway between Tavistock and Launceston, 

 over the ridge of Dartmoor by Cawsand Beacon, Spreyton, Morchard Bishop, 

 Puddington, Tenipleton to Tiverton and thence along Grand Western Canal 

 to county boundary. 5-6 : Somerset N. and S. ; rivers Parrett and Yeo to 

 county boundary at Mudford. 7-8: Wiltshire N. and S. ; Kennet and Avon 

 Canal. Ii-I2: Hants. N. and S. ; high roads from Winchester westwards 

 through Stockbridge and eastwards through Chilcombe and Petersfield to 

 boundary on Rogate road. 13-14 : Sussex E. and W. ; high road from 

 Brighton by Hassocks Station to Cuckfield and Crawley to Surrey boundary. 

 15-16 : Kent E. and W. ; rivers Medway and Beult to Maidstone — Goud- 



