DESCRIPTION OF THE PLATES. 



FIG. PAGE 



Plate I. 



1,2. Neritina fluviastilis 1 



3. Neritina fluviatilis, the 



operculum 2 



4.5. Paludina vivipara .3 



6.7. Paludina achatina 4 



S, 9. Paludina impura 4 



10, 11. Paludina ventricosa ... 5 

 12, 13. Assiminia Grayana 6 



14, 15. Valvata piscinalis 6 



16, 17. Valvata piscinalis, var. 7 



18,19. Valvata cristata 7 



20. Valvata cristata, young ... 7 



21,22. Lymnsea stagnalis 8 



23, 24. Lymnsea stagnalis, var. 8 



25. Lymnsea stagnalis, young.. 8 



26,27. Lymnsea minuta 9 



Plate IL 



1,2. Lymnsea palustr is 9 



3, 4, 5, 6, 7, 8, 9, 10. Lymnsea 



palustris, different varieties 9 



11, 12, 13, 14. Lymnsea auri- 

 cularia 11 



15, 16, 18, 19. Lymnsea peregra 11 



17, 20, 21, 22, 23, 24, 25. Lym- 



nsea peregra, different 



varieties 12 



27. Lymnsea involuta 13 



Plate in. 



1, 2, 3, 4. Lymnsea elongata. 10 



5.6. Amphipeplea lacustris... 14 



7.8. Amphipeplea glutinosa . . 13 

 9, 10. Physa acuta 16 



11, 12. Physa fontinalis, var. 1 15 



FIG. PAGE 



13,14. Physa fontinalis 15 



15, 16. Physa fontinalis, var. 2 15 



17, 18. Physa hypnorum 16 



19, 20. Planorbis spirorbis 23 



21, 22, 23. Planorbis corneus . 17 



24, 25. Planorbis contortus 24 



26, 27, 28. Planorbis marginatus 20 



29. Planorbis marginatus, a 

 lusus naturcE 21 



30, 31. Planorbis albus 18 



32,33. Planorbis vortex 22 



34, 35, 36. Planorbis carinatus. 20 



.37,38,39. Planorbis laevis .... 18 



40, 41. Planorbis imbricatus ... 19 



42, 43. Planorbis imbricatus, var. 19 



Plate IV. 



1,2. Planorbis nitidus 23 



3,4. Segmentina lineata 25 



5, 6. Planorbis marginatus, 



young 21 



7. Planorbis carinatus, var. ... 20 



8, 9. Carychium minimum ... 28 

 10, 11. Cyclostoma elegans ... 26 



12. Bulimus lubricus 34 



13, 14. Cyclostoma marmorea. 27 



15. Acme fusca 28 



16. Acme minuta 29 



17. 18. Bulimus montanus 34 



19. Succinea oblonga 31 



20,21. Succinea amphibia 30 



22, 23. Succinea gracilis, var. 31 



24, 24.* Bulimus obscurus 33 



26,27. Succinea gracilis 30 



28,29. Achatina Acicula 32 



30. Balsea fragilis 36 



