“There were then, perhaps, existing on or near the land, some of those reptiles which I shall describe in the next chapter; and with them were associated true crocodilians, not much unlike the fresh water gavial inhabiting the Ganges. These, also, might occasionally swim out to sea, and be found in the neighbouring shoals. “But these shoals were alive with myriads of invertebrated animals; and crowds of sharks hovered about, feeding upon the larger tribes. There were also numerous other animals, belonging to those remarkable groups which I have attempted to describe in some detail. Imagine one of these monstrous animals, a plesiosaurus, some sixteen or twenty feet long, with a small wedge-shaped crocodilian head, a long, arched, serpent-like neck, a short compact body, provided with four large and powerful paddles, almost developed into hands; an animal not covered with brilliant scales, but with a black slimy skin. Imagine for a moment this creature slowly emerging from the muddy banks, and, half walking, half creeping along, making its way towards the nearest water. Arrived at the water, we can understand from its structure that it was liable to exhibit greater energy. Unlike the crocodile tribe, however, in all its proportions, it must have been equally dissimilar in habit. Perhaps, instead of concealing itself in mud or among rushes, it would swim at once boldly and directly to the attack. Its enormous neck stretched out to its full length, and its tail acting as a rudder, the powerful and frequent strokes of its four large paddles would at once give it an impulse, sending it through the water at a very rapid rate. When within reach of its prey, we may almost fancy that we see it drawing back its long neck as it depressed its body in the water, until the strength of the muscular apparatus with which this neck was provided, and the great additional impetus given by the rapid advance of the animal, would combine to produce a stroke from the pointed head which few living animals could resist. The fishes, including perhaps even the sharks, the larger cuttle-fish, and innumerable inhabitants of the sea, would fall an easy prey to this monster.