Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/687

 a Tapes ; these shells are perfect ; but, although they are so numerous, many of the shells found in the banks at the creek and Ferreira's River are wanting. It is worth considering whether or not this indicates a series of these deposits. All the shells in the lowest part of the stratum at this spot have both valves perfect, some of the Mactroe still retaining a portion of their colour ; those imbedded in the limestone, nearer the surface, are in a more fragmentary condition.

The section I have called " the raised-beach " is, as above stated, some 40 or 50 feet above the level of the sea; but unfortunately the upper portion is the only part sufficiently exposed for examination. From the indications on the beach below, it most probably rests on a sandstone there shown. Almost every shell in the remains of this ancient beach is broken, in the same manner as those now found on the present sea-shore where exposed to the full action of the waves rolling in from the ocean.

At the creek on the Grahamstown Road this deposit has been cut through for some 12 feet in depth. Here, again, most of the shells are perfect, and do not seem to have been exposed to the action of rough water. This is eminently the case with the contents of the shell-bank further up Ferreira's River, and near Cradocktown. At this place the deposit rests upon a bank of drift, with bands of large angular pieces of quartzite ; this drift overlies a loose gritty sandstone. In the drift there are scarcely any indications of fossils ; but in the deposit above there are strata of innumerable shells in a sandy calcareous matrix. This shell-bed, capped with a red clay, several feet thick, is the most prolific portion of the deposit we are now treating of. The shells are all perfect, with the most delicate ornaments preserved.

With the exception of a Psammobia, none of the shells found here have, up to the present time, been found on the shores of the bay. Still, in the whole series of shells collected, there is a nearer approach to those of the present ocean, while there is a marked difference in character between these fossils and those obtained from the Akera- stratum.

These shell-deposits at Ferreira's River &c, must have been laid down in the waters of a bay, stretching from the Zwartkops to the Port-Elizabeth hills, and extending some miles inland. On the intervening ridges no signs of them are to be traced. In fact, it seems almost certain that the ridges must have stood out of the surrounding waters as islands. This is remarkably the case at the creek, where the high ridges alluded to will be seen. When standing on the shell-bank at Ferreira's River, one cannot help being strongly impressed with this idea, and that the sea must have been as calm there as in a land-locked bay, protected as it evidently was from the roll of the open ocean. The appearance of the shells themselves strengthens this view of the case, from the beautifully perfect state in which almost all of them are found — with all their most delicate outlines preserved, and the bivalves almost invariably having both valves uninjured and closed. These