71. A rolled fragment of yellowish-grey compact limestone (magnesian), of even and dull fracture; the surface shining, wrinkled by decomposition. “To the north and south of the Wells of Mafrass.”
72. The same variety as the preceding, in the shape of a large conical lump, with uneven and corroded glossy surface, enclosing rounded pieces of the same limestone. From ditto.
73. A similar variety of magnesian limestone, forming a botryoidal group of more or less globular concretions, from upwards of half an inch to half a line in diameter, and intimately grown together with each other. “Meshroo and El Wahr.”
74. Yellowish limestone, of curved-lamellar structure. “Forming veins in the basaltic rocks in Agutefa.”
75. Brownish-yellow limestone, in stalagmitical irregular layers. “On the desert, between Mushroo and El Wahr.”
76. Another fragment, apparently part of a large stalagmitic nodule, in layers on a yellow granular mass of carbonate of lime. From ditto.
77. Greyish-brown and hair-brown fibrous limestone, in tabular pieces; the fibres perpendicular, or in an oblique direction to the horizontal planes, straight or slightly curved. In some specimens, the hair-brown layer is sard-onyx and onyx-like, succeeded by a red and a white stratum, the former generally in the form of a crust, with superficial small acute rhombohedrons of carbonate of lime; in others, the hair-brown layer is traversed by white veins. “Boundaries of Fezzan and Tuarick country.”
78. Sulphate of barytes; a group of bluish and brownish prismatic crystals, (var. rétrécie of Haüy), covered by red marle.
79. Common salt, in white, opaque, granular aggregations, externally stained by ferruginous clay. “Road between Hamara and Zuela.”
80. A saline incrustation, of yellowish-white colour, partly solid, in thin tables, partly in powder, composed of carbonate, muriate, and sulphate of soda. “Near Germa.”