MOLLUSCS The number of species recorded for the county of Norfolk amounts to I GO, and this out of a total of 139, known to occur in the British Islands, may be considered a very high county average. It is an essentially British assemblage, offering no example of forms typical of the south-western or northern districts. So far as the distribution of its snails is concerned the county is roughly divisible into the low-lying marshy tracts of the river valleys, and the uplands. The ditches in the former yield an abundance of species, but the broads are tenanted by only a few kinds. In the uplands the hedgerow forms predominate ; but isolated ponds, even those which are nearly dry in summer, yield unexpectedly large numbers of specimens. An introduced species, Stenogyra goodalli (Mill), whose home is in the West Indies, has been found in hothouses at Carrow. A. GASTROPODA I. PULMONATA a. Stylommatophora Testacella haliotidea, Drap. Aylsham ; Did- dington Hall, Brandon ; Norwich (?) — scutu/um, Sby. Norwich, Foulsham, Lynn Lintax maximus, Linn. — flavui^ Linn. — arhorum, Bouch.-Chant. Agriolimax agrestis (Linn.) — iavis (Mull.) Amalia sowerbii (F^r.) — S^S^*^^ (Drap.) Vitrina pellucida (Mall.) Vitrea crystalHna (MUll.) — alliaria (Miller). Recorded from several places ; but specimens thus labeled have, so far as seen, proved to be the next species — glabra (Brit. Auct.). Costessey — cellaria (MuU.) — nitidula (Drap.) — pura (Aid.). Caistor St. Edmunds, Dun- ston — radiatula (Aid.). Near Norwich — nitida (MuU.). Plentiful in the Broad district — fitlva (Mull.) Arion ater (Linn.) — hortensis, F6r. — circumscriptus, Johp. St. Germans — intermedius. Norm. One or two places south of Norwich Punctum pygnneum (Drap.) Pyramidula rotundata (Mull.) Helicella virgata (Da C.) — itala (Linn.) — caperata (Mont.) — cantiana (Mont.). More plentiful south of Norwich than elsewhere in the county — cartusiana (Mtill.). One dead specimen near Long Stratton Hygromia granulata (Aid.) — hhpida (Linn.) — rufescens (Penn.) — Acanthinula aculeata (MUll.). Norwich, Stratton Strawless Vallonia pukhella (MuU.) Helkigona lapicida (Linn.). Norwich, Fram- ingham Earl — arbuitorum (Linn.) Helix aspersa, MuU. — nemoralis, Linn. — hortensis, MuU. Buliminus obscurus (Mull.) 87
