Lathkill River, 156. Lead, 33. Leland, 46. Lewsdon, 3. Lias, 27, 28, 29. Lion, 23, 24. Llangollen, 133. Long Hole, 19, 28, 97. Long Kin Hole, 37. Long Wood, 97. Lower Limestone Shales, 2, 4, 5. Loxton, 112, 113. Mammoth, 23, 24. Manifold, 150, 151. Marble Arch, 42. Marshall (Mr.), 11, 13. Martel (Mons.), 17, 19, 30, 34, 37, 39, 57, 145, 160, 161, 164, 165, 167. Master-joint, 34, 131. Matlock, 104. Mazauric (M.), 39. McMurtrie (Mr. J.), 122. Mendip plateau, 36. Middle Hill, 147. Mitchelstown Cave, 159. Monyash, 153. Morfa Rhuddlan, 131. Morland (Mr. J. O.), 83. Murray's Guide, 116, 122. Natural wells, 18. Neolithic barrows, 3. Niagara (Gough's Caves), 30. Nidderdale, 138. North Hill, 3, 60. O'Callaghan's Cave, 162, 165. Offa's Dyke, 133. Ogo, 45, 127. Ogof, 45, 127. Old Red Sandstone, 1, 2, 3, 4, 7, 11, 26, 53, 60. O'Leary's Cave, 161, 164. Ookey, 45. Oonakareaglisha, 159. Outfit, 41, 62. Padirac, 162. Parrett, 3. Peace of Wedmore, 3. Peak, 34, 38, 39, 42, 47, 144, 159. Peak's Hill, 147. Peak's Hole, 145. Peak's Hole (source of water of), 150. Pen Hill, 2, 4, 60. Percolating water, 6. Percy's _Reliques_, 46. Perryfoot, 145, 150. Phelps, 106. Phosphorites, 31. Pilsdon, 3. Pleistocene gravel, 28. Pliocene, 29. Plumley's Den, 100, 103, 104. _Polyolbion_, 47. Pot, 34, 84. Pothole Cavern, 155, 156. Potholes, 6, 68, 72. Pottery, 21, 22, 58, 74. Priddy, 7, 8, 17, 48, 60, 61, 98. Primitive man, 13, 22, 24, 34, 47, 128. Puttrell (Mr. J. W.), 138. Quantocks, 123. Quercy, 31. Radstock, 27. Radstock Coalfield, 10. Rain (action of), 6. Rakes, 33, 38. Ravine formation, 19. Ravines, 6, 20, 23. Raymond, Walter, 98. Red Deer, 23, 24. Reindeer, 23. _Reliquiæ Diluvianæ_, 33. Revolving stones (action of), 6. Rhaetic, 27, 31. Rhinoceros, 24. Rickford, 28, 102, 104. Ricklow Cavern, 157. Ricklow Dale, 153. Risings (extent of flow), 17. "Rock of Ages," 104. Rock shelter, 15. Roman Cave of Cheddar, 93, 95. Roman mines, 97. Romano-British pottery, 21, 22, 58, 74. Rookham, 2, 28. Rowberrow Farm, 17. Rushup Edge, 144, 147. Russet Well, 144, 145. "S" bends, 65, 68. St. Andrew's Well, 5, 28, 31. St. Dunstan's Well, 10, 11. St. George's Cave, 127, 130. "St. Paul's," 86, 88. St. Swithin's Hole, 7. "Salle à Manger," 38. Sand (action of), 6. Sand Pit Hole, 8. Schmidl (Dr. Adolph), 34. Scotchman's Cave, 165. Secondary Rocks, 5, 12, 18, 27, 28. Sedgemoor, 3. Severn, 4. Shakeholes, 29. Sheldon (Dr.), 83, 84, 90, 100. Sheldon (Mr., of Wells), 17. Shipham, 100. Silt, 10, 11. Siphons, 33, 34. Skeheenarinky, 159. Slater (Mr.), 71. Smith (W. W.), 45. Snowdonia, 130. Société de Spéléologie, 34.