THE MOST ANCIENT FISHES.
Among the important results of Sir Roderick Murchison’s establishment of the Silurian system is the following:
That as the Lower Silurian group, often of vast dimensions, has never afforded the smallest vestige of a Fish, though it abounds in numerous species of the marine classes,—corals, crinoidea, mollusca, and crustacea; and as in Scandinavia and Russia, where it is based on rocks void of fossils, its lowest stratum contains fucoids only,—Sir R. Murchison has, after fifteen years of laborious research steadily directed to this point, arrived at the conclusion, that a very long period elapsed after life was breathed into the waters before the lowest order of vertebrata was created; the earliest fishes being those of the Upper Silurian rocks, which he was the first to discover, and which he described “as the most ancient beings of their class which have yet been brought to light.” Though the Lower Silurian rocks of various parts of the world have since been ransacked by multitudes of prying geologists, who have exhumed from them myriads of marine fossils, not a single ichthyolite has been found in any stratum of higher antiquity than the Upper Silurian group of Murchison.
The most remarkable of all fossil fishes yet discovered have been found in the Old Red Sandstone cliffs at Dorpat, where the remains are so gigantic (one bone measuring two feet nine inches in length) that they were at first supposed to belong to saurians.
Sir Roderick’s examination of Russia has, in short, proved that the ichthyolites and mollusks which, in Western Europe, are separately peculiar to smaller detached basins, were here (in the British Isles) cohabitants of many parts of the same great sea.