DESCRIPTION OF THE PLATES. 



141 



Plate XXIV. 



1,2,3. Cyclas rivicola 116 



4. Cyclas cornea 117 



5. Cyclas lacustris 117 



6. Cyclas calyculata 118 



7. Pisidium obliquum 118 



8. Pisidium fontinale 119 



9. Pisidium obtusale 120 



10. Pisidium appendiculata .... 120 



11. Pisidium nitidum 121 



12. Pisidium pusillum 121 



13. Pisidium cinereum 121 



14. Pisidium pulchellum, Leach 119 

 15,15. Cyclas citritia 131 



16. Neritina fluviatilis, animal. 123 



17. Assiminia Grayana, animal 123 



18. Valvata piscinalis, animal.. 123 



19. Paludiua vivipara, animal.. 123 



20. Paludina vivipara, young . . 123 



21. Operculum of Paludina 

 vivipara 123 



22. Succinea amphibia, animal 125 



23. Vertigo sexdentata, animal 126 



24. Cyclostoma elegans, animal 124 



25. Ancylus fluviatilis, animal. 129 



26. Planorbis cornea, animal... 124 



27. Physa bypnonun, animal... 124 



28. Clausilia nigi-icans, animal. 125 



29. Spawn of Planorbis contor- 



tus 125 



30. Spawn of Planorbis contor- 

 tus, magnified 125 



31. Spawn of Lymnseus pere- 

 gra, var. ovata 124 



32. Spawn of Lymnasus pere- 

 gra, var. ovata, magnified. 124 



33. Spawn of Physa fontinalis. 124 



34. Spawn of- Planorbis corneus 124 



35. Spawn of Paludina impura 123 



36. Spawn of Succinea amphi- 

 bea 125 



37. Spawn of Succinea amphi- 

 bea, magnified 125 



38. Spawn of Valvata cristata, 

 magnified 123 



FIG- PAGE 



40. Spawn of Paludina impura, 

 magnified 123 



4 1 . Spawn of Lymnaea peregra, 

 natural size 124 



4 2 . Spawn of Lymnsea peregra. 



eggs magnified 124 



43. Spawn of Lymnsea peregra, 

 magnified 124 



44. Lymnsea stagnalis, animal. 124 



45. Egg of Physa fontinalis, 

 magnified 124 



46. Spawn of Physa fontinalis, 

 magnified 124 



55. Spawn of Valvata obtusa.. 123 



Plate XXV. 



1. Vitrina pellucida, animal... 126 



2. Heli-x nemoralis, animal ... 126 



3. Helix cellaria, animal 126 



4. Helix caracolla, animal .... 126 



5. Helix aspersa, animal 126 



6. Orifice of Heli.x aspersa ... 126 



7. Dart of Helix aspersa 126 



8. Section of Helix aspersa... 126 

 9 Eggs of Helix nemoralis... 126 



10. Eggs of Limax rufus 126 



11. Eggs of Helix Pomatia ... 126 



12. Limax Sowerbii 128 



13. Limax Sowerbii, resting 

 position 128 



14. Limax gagates, young 129 



15. 16. Limax gagates, var. ... 129 



17, 19, 20. Limax gagates, rest- 



ing position 129 



18. Limax gagates 129 



21,22. Limax flavus 128 



Plate XXVI. 



1 . Testacella Haliotoidea, ani- 

 mal 127 



2, 8. Limax arboreus, var. ... 127 



3. Limax arboreus 127 



4, 5. Limax arboreus, resting 



position 127 



6, 7. Limax arboreus, young, 127 



