Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/178

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Fig. 5. Cerithium kaffrarium, n. sp.

Figs. 6, 6 a. Solarium Wiebeli, n. sp., enlarged ; 6 b, natural size.

Fig. 7. Pecten amapondensis, n. sp.

Figs. 8, 8 a, 8 b. Pectunculus africanus, n. sp.

Fig. 9. Astarte, sp.

Figs. 10, 10 a, 10 b. Arca capensis, n. sp.

Figs. 11, 11 a, 11 b, 11 c. Trigonia Shepstonei, n. sp.

Fig. 12. Cardium denticulatum, Baily.

Fig. 13. Diadema, sp.

Discussion.

Prof. T. Rupert Jones commented on the importance of the paper as throwing so complete a light on the geology of Natal, and proving the geological sequence to be similar there to that in other parts of Southern Africa. He remarked that the author had done special service by the great increase of information furnished by him regarding the Cretaceous rocks of Natal, and their equivalence to those of India. He also pointed out that Mr. Griesbach had proved that the Karoo formation was continuous to the other side of the great dividing range, and formed the floor of the Orange and Waal valleys, and remarked that as Mr. Stow had indicated glacial action on the south side of the Orange valley, it was quite possible that the gravels containing the diamonds were of local origin, as Dr. Grey had suggested.

4. On the Diamond-districts of the Cape of Good Hope.

By G. Gilfillan, Esq.

(Communicated by Warington W. Smyth, Esq., F.R.S., F.G.S.)

[Abstract.]

In this paper the author gave an account of a visit paid by him in June last to the diamond-bearing districts of the Cape of Good Hope.

Between Cradock and Hope Town there seemed to be no indications to warrant the expectation of finding diamonds. The geological structure of the country between Cradock and Middelburg is very uniform, showing few traces of upheavals. The rocks are chiefly sandstones of various degrees of fineness, with alternating beds of red or blue marl, in hard nodules of which Dicynodon-remains are formed.

On the " Karoo " the author noticed that all the springs in that country rise on the eastern side of dykes which run about N.E. and S.W. Near Hope Town there are immense tracts of sand. This village is surrounded by low bluffs of a peculiar rock, consisting of a calcareous matrix with waterworn pebbles. At Hope Town an active trade in diamonds is carried on.

The author crossed the Orange River at Hope Town, and describes the tract of country between that and the Vaal River, called Albania, as very barren of geological interest, being chiefly a sandy waste, with a few low hills, dykes of greenstone, trap, &c, and occasionally