No. of
Family. Genus. Species. Distribution.
35. Tornatella 16 Red Sea, Philippines, Japan--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.