INDEX. 



PLATE 1. 

 Pig. Page. 



1 Unio margaritiferus ... 13 



2 Cyclas rivicola 7 



3 Cyclas cornea 8 



4 Cyclas caliculata 8 



5 Cyclas lacustris 8 



6 Pisidium obtusale 9 



7 Pisidium pusillum 9 



8 Pisidium cinereum 10 



9 Pisidium nitidum ...... 10 



10 Pisidium pulchellum ... 11 



11 PisidiumHenslowianum 11 



1 2 Pisidinm amnicum 12 



PLATE II. 

 1 Anodonta cygnea ...14, 15 



PLATE III. 



1 Unio pictorum 13 



2 Unio tumidus 12 



3-4 Dreissena polymorpha . . 16 



PLATE IV. 



1 Neretina fluviatilis 16 



2 Assiminia Grayana 19 



3 Valvata cristata 19 



4 Valvata piscinalis 19 



5 Paludina Listeri 17 



6 Paludina vivipera 17 



7 Bithinia tentaculata ... 18 



8 Bithinia Leachii 18 



9 Limax agrestis 21 



10 Limax Sowerbii 24 



11 Limax gagates 24 



1 2 Limax cinereus 22 



13 Limax tenellus 23 



14 Limax arborum 22 



PLATE V. 



1 Avion empiricorum 20 



2 Limax brunneus 23 



Fig. Page. 



3 Anon hortensis 21 



4 Limax flavus 23 



5 Testacella haliotoidea... 24 



6 Geomalacus maculosus. 21 



7 Arion flavus 20 



8 Zonites cellarius 26 



9 Zonites nitidulus 27 



1 Zonites radiatulu s 28 



1 1 Zonites cry tallinus 30 



12 Vitrina pellucida 25 



13 Zonites alliarius 26 



14 Zonites purus 27 



15 Zonites nitidus 28 



16 Zonites excavatus 29 



17 Helix pomatia 31 



PLATE VI. 



1 Helix aperta 30 



2 Helix aspersa 31 



3 Helix nemoralis 33 



4 Helixhybrida 34 



5 Helix arbustorum 32 



6 Helix hortensis 33 



7 Helix hispida 38 



8 Helix pisana 34 



9 Helix Cantiana 32 



10 Helix virgata 34 



11 Helix sericea 39 



12 Helix Carthusiana 33 



13 Helix lamellata 39 



14 Helix fulva 40 



15 Helix caperata 35 



16 Helix lapicida 36 



17 Helix aculeata 40 



18 Helix ericetorum 35 



19 Helix rufescens 37 



20 Halix pulchella 41 



21 Helix obvoluta 36 



22 Helix revelata 38 



23 Helix rotundata 41 



24 Helix fusca .. ..40 



