19. Turbo 60 On the sh.o.r.es of Tropical seas.

Phasinella 30 Australia, Pacific, W. Indies, Mediterranean.

Imperator 20 S. Africa, India, etc.

Trochus 150 World-wide--from low water to 100 fathoms.

Rotella 18 India, Philippines, China, New Zealand.

Stomatella 20 Cape, India, Australia, etc.

20. Haliotis 75 Britain, Canaries, India, Australia, California--on rocks at low water.

Stomatia 12 Java, Philippines, Pacific, etc.-- under stones at low water.

21. Ianthina 6 Gregarious in the open seas of the Atlantic and Pacific.

22. Fissurella 120 World-wide--on rocks from low water to 5 fathoms.

Emarginula 26 Britain, Norway, Philippines, Australia--from low water to 90 fathoms.

23. Nerita 116 On the sh.o.r.es of all warm seas.

Neritina 110 In fresh waters of all warm countries, and in Britain.

Navicella 24 India, Mauritius, Moluccas, Australia, Pacific--in fresh water, attached to stones.

24. Patella 100 On all coasts--adhering to stones and rocks.

25. Dentalium 30 World-wide--buried in mud.

26. Chiton 200 World-wide--low water to 100 fathoms.

ORDER II.--Pulmonifera.

Division _a_.--_Inoperculata._

No. of Family. Genus. Species. Distribution.

27. Helix 1,600 } Succinea 68 } World-wide--on land in moist places.

Bulimus 650 } Achatina 120 World-wide--burrowing at roots and bulbs.

Pupa 236 World-wide--amongst wet moss.

Clausilia 400 Europe and Asia--in moist spots.

28. Limax 22 Europe and Canaries--on land in damp localities.

Testacella 3 S. Europe, Canaries, and Britain-- burrowing in gardens.

29. Oncidium 16 Britain, Red Sea, Mediterranean--on rocks on the seash.o.r.e.

30. Limnaea 50 Europe, Madeira, India, China, N.

America--in ponds, rivers, lakes, etc.

Physa 20 America, Europe, S. Africa, India, Philippines--in ponds, rivers, lakes, etc.

Ancylus 14 Europe, N. and S. America--in ponds, rivers, lakes, etc.

Planorbis 145 Europe, N. America, India, China--in ponds, rivers, lakes, etc.

31. Auricula 50 Tropical--in salt marshes.

Siphonaria 30 World-wide--between high and low water.

Division _b_.--_Operculata._

32. Cyclostoma 80 S. Europe, Africa } Cyclophorus 100 India, Philippines }--on land.

Pupina 80 Philippines, New Guinea } 33. Helicina 150 W. Indies, Philippines, Central America, Islands in Pacific--on land.

34. Acicula 5 Britain, Europe, Vanicoro--on leaves and at roots of gra.s.s.

Geomelania 21 Jamaica--on land.

ORDER III.--Opisthobranchiata.

Division _a_.--_Tectibranchiata._

No. of Family. Genus. Species. Distribution.

35. Tornatella 16 Red Sea, Philippines, j.a.pan--in deep water.

36. Bulla 50 Widely distributed--low water to 30 fathoms.

37. Aplysia 40 Britain, Norway, W. Indies--low water to 15 fathoms on sea-weed.

38. Pleurobranchus 20 Britain, Norway, Mediterranean.

Division _b_.--_Nudibranchiata._

39-44. All sh.e.l.l-less.

ORDER IV.--Nucleobranchiata.

No. of Family. Genus. Species. Distribution.

45. Firola 8 Atlantic, Mediterranean.

Carinaria 5 Atlantic and Indian Oceans.

46. Atlanta 15 Warmer parts of the Atlantic.

CLa.s.s III.--PTEROPODA.

Division _a_.--_Thecosomata._

No. of Family. Genus. Species. Distribution.

1. Hyalea 19 } Cleodora 12 } Atlantic, Mediterranean, Indian Ocean.

2. Limacina 2 Arctic and Antarctic Seas.

Division _b_.--_Gymnosomata._

3. Clio, etc. Sh.e.l.l-less.

CLa.s.s IV.--LAMELLIBRANCHIATA.

No. of Family. Genus. Species. Distribution.

Division _a_.--_Asiphonida._

1. Ostrea 100 World-wide--in estuaries, attached.

2. Anomia 20 India, Australia, China, Ceylon-- attached to sh.e.l.ls from low water to 100 fathoms.