A reference to the geological sequence will show the stratigraphical position of the phosphatic series of the oasis, consisting of hard bands composed of fish-remains, coprolites, and phosphatic nodules. The beds have a wide extension in Northern Kharga, and are especially well developed on the flanks of Jebel Tarwan and Jebel Têr, in the centre of the depression. As a rule, they consist of an upper brown-coloured series, individual beds of which in places have a thickness of 2 or 3 metres, and a lower division consisting of three or four thin, hard, and lighter-coloured bands, in which the phosphatic nodules are often cemented by iron pyrites. The upper bands may contain anything up to 60 per cent. of tricalcium phosphate, so that the deposit may be regarded as of considerable potential value. CHAPTER XVI SOME NOTES ON SPORT AND NATURAL HISTORY The Libyan Desert as a Sporting Region — The Dorcas Gazelle — Snipe — Wild-Fowl — The Local Sportsmen — An all-night Sitting — Quail — Sand-Grouse — Rock-Pigeons — Turtle-Doves — Various — Striped Hyæna — Jackals — Three Species of Fox — The Desert Fox — The True Fennec. Sportsmen who reckon the success and pleasures of a shooting expedition only by the contents of the resulting bag are advised to give a wide berth to the Libyan Desert, as in that arid region—with the exception of one restricted area far removed from the oasis under description—no game is to be found which cannot be obtained far more easily, and in much greater quantities, in the cultivated plains of the Nile Valley and on the adjoining desert margins. On the other hand, the sportsman who does not regard too seriously the actual head of game brought to bag, and who has no objection to hard work, will find in the oases undoubted attractions in the way of rough sport. Provided with a few camels to carry the necessary impedimenta, so as to be rendered independent and able to wander about at will, a very enjoyable time can be spent exploring the various isolated portions of the depression where gazelles abound, and visiting the numerous outlying wells where wild-fowl, snipe, quail, sand-grouse, and rock-pigeons are to be met with in fair quantities.