From these facts Geologists have been led to conclude:--that the strata in question were deposited on the bed of an ancient sea in which these fishes swam; that the waters of the sea were suddenly rendered noxious, probably by the eruption of volcanic matter; that the fishes in consequence perished in large numbers, and were then almost immediately embedded in the calcareous deposits of which the strata are composed. These views receive no small confirmation from a very remarkable phenomenon to which we may be allowed, in passing, to call attention. In the year 1831 a volcanic island was suddenly thrown up in the Mediterranean between Sicily and the African coast; and the waters of the sea were at the same time observed to be charged with a red mud over a very wide area, while hundreds of dead fish were seen floating on the surface. Is it not pretty plain that when the mud subsided many of the fish were enveloped in the deposit, and thus preserved to future times? If so, then, we should have an exact modern parallel to the fossil fishes of Monte Bolca. But for the present it is our purpose rather to describe facts than to develop theories.[74] Near the town of Aix, the ancient capital of Provence, in the south of France, is a group of strata, consisting chiefly of Conglomerate, Marl, Gypsum, and Limestone, which has earned for itself no small fame in the annals of Geology. Besides many curious relics of an extinct vegetation, these strata yield also an abundance of Fossil Insects, which emerge from the rocky bed in which they have slept for ages, with a surprising freshness and a life-like reality. But the quarries of Aix, like those of Monte Bolca, are chiefly famous for their Fossil Fish. And in this case, too, as in the former, it would seem as if vast multitudes had suddenly perished together from some mysterious cause, and were then as suddenly entombed. They exhibit no mark of mechanical violence: and yet they are found, not unfrequently, crowded together as closely as they can fit, in every variety of position, on the same slab of limestone. A good example of such a block is represented in our woodcut. [Illustration: Fig. 16.--Fossil Fish from Aix.]