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 ZOOLOGY MOLLUSCS Although the county of Hereford is fairly prolific in MoUusca, being hilly and well wooded, it is not a very happy hunting ground, the soil not favouring moUuscan life. Nine-tenths of the area consists of Old Red Sandstone, with only here and there some impure limestone nodules. This is largely masked in the valleys by drift beds of gravel, clay, and sand. There are some limestone bands exposed in the small patch of Silurian beds in the north, as well as at Woolhope and to the east of Ledbury, while in the south-east corner the Wye cuts its way through cliffs of Carboniferous Limestone. These limestone areas are more prolific of snails. The rapid current and frequent floods of the Wye and smaller streams cause them to yield little, though the more sluggish Lugg, with its rich water meadows, shelters a good many species. Small ponds are numerous, but frequently fouled by cattle or cleaned out by ducks. Of the 146 or so species recorded for these islands, Herefordshire may be credited with about 94, including two. Vertigo substriata and V. pusilla, from a Holocene deposit at Ledbury, and Planorbis corneas introduced into a pond at Broomy Hill. Several records have had to be rejected on account of error in locality, a collection in the Hereford Museum having been labelled ' Hereford ' that had been brought together from many parts of England. On the other hand, several more species should be forthcoming with further research. The most interesting occurrence of those chronicled is, perhaps, that of • Helicella cantiana, the Kentish snail, at Dinmore (although this is only on the authority of an isolated record), especially in view of the fact that attempts made to establish colonies of it near Hereford failed. The species belongs to the southern and eastern parts of England, and is not plentiful in the Severn valley. With the exception of 'Jaminia = Pupd anglica, none of the more typically western forms are present in the district. The published papers dealing with the moUuscan fauna of Herefordshire are indeed scanty ; in fact there is only one memoir of any note, and that is the excellent and most thorough monograph by A. E. Boycott and E. W. W. Bowell,^ on which, supplemented by the Records of the Concho- logical Society, this account is based. The nomenclature adopted in the following list is that of the Conchological Society issued in 1904, and differs from that employed in the earlier county histories of this series. Where the names here used differ from those previously given, the latter are added in square brackets in order to facilitate comparison. ' Trans. Woolhope Nat. Field Club, 1888-9, ^^'^■^^ paper, pp. 104. 77