_Great Britain._--There are in all about 130 species--83 land, 46 fresh-water; _Limnaea involuta_ (mountain tarn near Killarney) appears to be the only peculiar species. There are 11 _Hyalinia_, 5 _Arion_, and 25 _Helix_, the latter belonging principally to the sub-genera _Xerophila_, _Tachea_, _Trichia_, and _Fruticicola_. Three _Testacella_ are probably not indigenous, but are now so well established as to reckon in the total. Of the four _Clausilia_ two reach Ireland and one Scotland; two do not occur north of the Forth. There are only two land operculates, one of which (_Cyclostoma elegans_) occurs in Ireland but not in Scotland, while the other (_Acicula lineata_) reaches the southern counties of Scotland. Several species, _e.g._ _Helix pomatia_, _H. obvoluta_, _H. revelata_, _H. cartusiana_, _H. pisana_, _Buliminus montanus_, are restricted to the more southern or western counties; _Geomalacus maculosus_ is confined to a district in south-western Ireland. The Pleistocene beds of East Anglia contain a number of species now extinct in these islands, whose occurrence appears to indicate a warmer climate than the present. Such are _Helix ruderata_, _H. fruticum_, _H. incarnata_, _Clausilia pumila_, _Unio littoralis_, _Hydrobia marginata_, and _Corbicula fluminalis_. _Scandinavian Peninsula._--From Norway 121 species in all are recorded, and 148 from Sweden. The milder climate of Norway allows many species to reach a considerably higher latitude than in Sweden, thus in Sweden _Limax maximus_ only reaches 62°, but in Norway 66° 50´. Similarly _Arion hortensis_ and _Balea perversa_ only reach 63° and 61° respectively in Sweden, but in Norway are found as far north as 69° and 67° 50´. _Clausilia_ is represented by 9 species in southern Norway; one of these is found north of the Arctic circle. There are 4 _Pupa_, 9 _Vertigo_, and 11 _Hyalinia_, but _Helix_ dwindles to 14, 9 of which occur north of the Arctic circle. No land operculates are found; _Cyclostoma elegans_, however, occurs in Jutland and Zealand, which practically form a part of this district. _Iceland._--Eleven species, all Scandinavian, occur. These are _Arion_ 2, _Limax_ 1, _Helix_ 2 (_arbustorum_ L. and _hortensis_ Müll., the latter being found only on the warmer southern coast), _Limnaea_ 1, _Planorbis_ 1, _Pisidium_ 4.