say; but at any rate the situation did look serious, since rescuers might have taken days to discover our position in this remote corridor, of whose very existence, probably, our guide was the only man in Ireland that knew anything. But where there is a way in, there is a way out, as I very well knew from several similar experiences; and after a pretty bad half-hour, we did manage to recover the trail, and got back to our friend, who had been completely mystified by our disappearance, and was almost as relieved as we by our return. After many hours of fatiguing work, we were glad to follow our guide back through the labyrinthine passages, by the most direct route to the open air. Our chief regret was that we had relied too much on the completeness of previous surveys, and had not taken materials for correcting the map. We had secured many photographs of the earlier chambers, but had not taken the camera into the innermost cavities, where photography would be most profitable. M. Martel's dictum can still be endorsed that there is a great field for research in the Mitchelstown Cavern. INDEX Abergele, 123. _Abîmes, Les_, 34, 39. Adelsberg, 43, 162. Albanets of Couvin (Belgium), 31. Alfred (King), 3. Alps, 43. Anemolites, 90. _Angels and Men_ (quotation), 45. Antiquity of caverns, 18, 21, 25. Apjohn (Dr.), 161. Arragonite, 119, 124. Arthur (King), 2. Attrition, effect of, 29. Avalon, Isle of, 2. Aveline's Hole, 99, 103. Aven de Vigne Close (Ardèche), 37. Avignon, 33. Axbridge, 106. Axe, the river, 2, 3, 5, 7, 23, 25, 26, 27, 31, 36, 46, 57, 70, 82. Badger Hole, 13, 23. Bagshawe Cavern, 42, 93. Balch (Mr.), 31, 36, 37, 48, 61, 71, 83, 101. Bamforth (Mr. H.), 71, 83, 85, 100, 138. Banwell Cave, 22, 28, 113. Barnes (Mr.), 71. Bath, 10, 69. Bats, 54, 93, 125. Bear, 14, 23, 24. Beehive, 30. Beehive Chamber, Lamb's Lair, 117. Betsy Camel's Hole, 14. Bishop's Lot Swallet, 8. Bishop's Palace at Wells, 5. Bison, 23, 24. Blackdown, 3, 17, 99, 104. Blackwater, 159. Blue John Mine, 38, 88, 90. Bonheur (Gard), 39. Bos, 14. Boule (M.), 31. Bouvier (M.), 33. Bowling Alley, 139. Bramabiau (Gard), 39. Bristol, 1, 2, 69. Bristol Channel, 3. Brogden's Cave, 166. Brue, 2, 3. Buckland (Dean), 33. Bull Pit, 147, 148, 149. Bunter Sandstone, 129. Burrington, 17, 28, 42, 62, 97, 99, 102, 104. Buxton, 29. Cadbury, 3. Calamine, 33. Cales Dale, 154, 155, 156. Camden's _Britannia_, 46. Camelot, 3. Canyon, 64, 65, 72, 73, 81, 150. Carbonic acid (action of), 4. Carboniferous or Mountain Limestone, 1, 2, 3, 4, 5, 7, 10, 11, 26, 28, 29, 53, 106. Cascades, 6. Castle of Comfort, 17, 29. Castleton, 37, 144, 157. Causse de Gramat (Padirac), 40. Cave-earth, 21. _Cave Hunting_, 47. Cave Man of Cheddar, 85, 86. Ceiriog Valley, 133. Cevennes, 37.