North-west from the diamond walls is a gallery to the Selina Cave. Midway, or about 20 yards from the junction at the diamond walls, is "Cook's Grotto," named after Mr. Samuel Cook, of Marrickville. It is a lovely nook, with stalactites of rare purity and beauty. This grotto is about five feet high and from 2 to 10 feet wide. In front is a conical sloping rock with a waxy-looking reticulated surface; and the grotto itself is filled with stalactites as white as the foam of an ocean billow dashed upon the rocks of an iron-bound coast. Between two of the principal stalactites is a fine "shawl" or "scarf," made of the purest meerschaum. Over the Grotto is some pretty formation, and round about are many coloured stalactites, which make a striking contrast. To the left is a splendid alabaster stalagmite, semi-transparent, like camphor, and the little stalactites above, from which it has been formed, are of similar character, being slightly opalescent, and without any stellar reflection of light. The Selina Cave, 30 yards north of Cook's Grotto, is about 20 feet high, 20 yards long, and 25 feet wide. It is named in honour of the wife of the Hon. E. B. Webb, M.L.C., of Bathurst, and in recognition of the interest in the caves taken by the Webb family from time to time. The walls are heavily laden with ornament. There is on the right hand side a lavish supply of variously-coloured stalactites. A large mass of formation has flowed from the fore part of the ceiling to the left, and assumed all sorts of graceful and fantastic shapes, until it reaches a shell pattern composite dwarf wall on the floor, about a foot thick at the base, and thinning off to about an inch at the top. The best of the stalactites are objects of great curiosity on account of the peculiar way in which they are embellished by small gnarled and twisted projections, and protuberances like miniature stalactitic Protea in every conceivable kind of tortuosity. In front of the cave is a magnificent stalagmite called "Lot." It is about 18 feet high and two feet in diameter, and may be supposed to represent the Patriarch after his capture by the confederate monarchs who made war against the Kings of the Cities of the Plain. It is rather large, but then it is recorded--"there were giants in those days." It is not on record why this particular column is called "Lot." Perhaps it was thought that the briny tears shed by the son of Haran on account of the loss of his wife would be sufficient to make a second pillar of salt of similar dimensions. The roof opening into the cave is adorned with stalactites, and on the floor there are besides "Lot" two other remarkable stalagmites, which may be taken to represent members of his family. In shape they are probably quite as representative as Noachian figures of Mesdames Shem, Ham, and Japhet, that give variety to the contents of those wonderful arks which are supposed to convey to the juvenile mind the principal incidents associated with the Deluge.