31. The same, fine-grained, white, with linear purplish streaks, being the edges of horizontal filmy depositions of iron ochre of that colour. Wady Kawan.
32. A similar variety, exhibiting purplish-yellow and red variegations, thoroughly impregnated with salt, which is also seen efflorescent on the surface. “Hills of Wady Ghrarbi.”
33. Similarly coloured sandstone, in laminar fragments, passing, by decomposition, into soft clay variegated with the same colours. Wady Kawar.
34. Tabular fragment of very close-grained nearly compact variegated sandstone; colours, purplish and two shades of yellow, in irregular stripes. “Sebha district.”
35. Purplish-brown slaty sandstone, micaceous on the planes of separation, passing into cream yellow and white clay-stone of the same structure. “Aluminous slate (sic) in different states, forming a considerable part of the mountain range, Tadrart, Tuarick country.”
36. A tabular fragment, like the preceding; micaceous on the rifts, of reddish-brown colour, being thoroughly penetrated by oxide of iron. Aghadem.
37. Yellowish sandstone, composed of round grains of quartz, with white clayey cement, which, towards the surface of the rolled piece, becomes quartzy. From ditto.
38. A similar large-grained variety, of reddish-yellow colour with brown streaks, in which the cementing clay, become quartzy, is scarcely distinguishable from the grains. “Forming the eastern boundary of the hills near Traghen.”
39. A large fragment of the same quartzy sandstone, of yellow colour, with red streaks and brown nucleus, nearly compact, so as to exhibit on its conchoidal fractural surfaces the traces only of a granular structure. “Strewed over the plain between Ghudwa and Mourzuk.”
40. The same, brownish-red, in the shape of a rolled amorphous fragment, having acquired a uniform glossy surface like red jasper. From ditto.