Belemnites two feet long have been found, so that, to judge by analogies, the animals to which they belonged as cuttle-bones must have measured eighteen or twenty feet from end to end. Provided with prehensile hooks on their long arms, and with a formidable parrot-like bill, these huge creatures must have proved most dangerous antagonists, even to the well-protected fishes that lived in the same seas. But of all the denizens of the Mesozoic Ocean none were more powerful than the large marine or enaliosaurian reptiles, which, flourishing throughout the whole of the Triassic period, were lords of all they surveyed down to the end of the Cretaceous epoch. First among these monsters appears the gigantic Ichthyosaurus, which has been found no less than forty feet long—a creature half fish, half lizard, and combining, in strange juxtaposition, the snout of the porpoise, the teeth of the crocodile, and the paddles of the whale. But the most remarkable of its features is the eye, surpassing a man’s head in size, and wonderfully adapted for vision both far and near. [Illustration: ICHTHYOSAURUS COMMUNIS.] [Illustration: PLESIOSAURUS DOLICHODEIRUS. (British Museum—Found in the Lias of Street, near Glastonbury.) ] In the quarries of Caen in Normandy, at Lyme Regis in Dorsetshire, and particularly at Kloster Banz in Franconia, where the largest known specimen has been discovered, entire skeletons of the formidable Ichthyosaurus have been exhumed from the Liassic shale—memorials of the ages long since past, when lands now far removed from the ocean still lay at the bottom of the sea, and formed the domain of gigantic lizards. The enormous jaw-bones of the Ichthyosauri, which in the full-grown animal could be opened seven feet wide, were armed along their whole length with powerful conical teeth, showing them to have been carnivorous, and the half-digested remains of fishes and reptiles found within their skeletons indicate the precise nature of their food. The size of the swallowed object proves also that the cavity of the stomach must have corresponded with the wide opening of the jaws. Thus powerfully equipped for offensive warfare; excellent swimmers from their compressed cuneiform trunk, their long broad paddles, and their stout vertical tail-fin; provided, moreover, with eyes capable of piercing the dim light of the ocean depths, they must have been formidable indeed to the contemporaneous fishes.