Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/668

 are few either natural or artificial cuttings through these strata anywhere.

In the uppermost stratum, No. 1, Section G, I found a number of Astarte Longlandsiana. In one small mass of rock I obtained upwards of twenty specimens of different sizes. In a small kloof near the top of one of the hills, near the Modder Drift, Col. Rocke and I discovered a place where this fossiliferous bed was exposed, containing innumerable remains of Pinna Atherstonei. I have never seen such a collection of these shells at any other spot. From this circumstance we named it " Pinna Kloof." Trigonia Herzogii is also numerous here. If these rocks prove to be, as I suppose, the equivalents of those at McLoughlin's, there is to be noticed that, whereas at the latter place the whole series occupies a space of but some 40 or 50 feet in thickness, here, above the Modder Drift, the fossiliferous beds are not only thicker themselves, but are separated by wider spaces of non-fossiliferous rock, it being a height of some 200 or 250 feet from the lowest stratum to the top of " Pinna Kloof."

I was not able to make any satisfactory observation of the dip of these lower rocks during my visit ; but some four or five miles to the west, on the plateau over which the road passes from the Bay to Tunbridge's, I found that the dip of the upper sandstones was at an angle of 9°, with an apparent direction of 32° E. of S., taking a slope from the higher portions of Grass-ridge towards the coast. These latter rocks, where I obtained this observation, are at a higher elevation than those examined along the banks of the Sundays River ; but whether the dip here taken is likely to indicate the true dip of the lower rocks under notice I am not at present able to say. A quantity of fossil wood was strewed among the debris of these strata, although I did not find any in situ ; and Dr. Rubidge informed me that he had found Ammonites in the same locality.

As a recapitulation of the foregoing, I would observe that the facts here stated, imperfect as they are, and modified as the conclusions here arrived at no doubt may be with increased information, show that most of the fossiliferous bands in the different localities of the " Uitenhage Formation " form portions of a series, and are not continuations of the same zone, as was once thought. This, I believe, will be proved to be the case, very convincingly, as soon as their fossils are more accurately tabulated. Thus, in No. 13, at the old road near Rocke's Bluff, Astarte Bronnii is in very large numbers, both valves of most of these shells beautifully perfect. This is the only band from which this Astarte, as far as I can learn, has been obtained, while I am not aware that a single Trigonia has ever been found there. In No. 12, Exogyra imbricata is exceedingly numerous ; but not one specimen of Astarte Bronnii has been discovered in it. Here one or two Trigonioe make their appearance, but are very scarce ; while in No. 11, near the drift, on the old road to Grahamstown, Trigonia Herzogii becomes one of the characteristic shells. In No. 11 also, Cuculloea Kraussii, Astarte Her-