visual apparatus ever seen in creation. Hence the ichthyosauri could discover their prey at the greatest as well as the shortest distances; in the profound darkness of night, and in the depths of the ocean; the delicate structure of the organ of vision being protected from the shock of the waves by the bony buckler which surrounds the transparent globe.

Naturalists have investigated the remains of these animals with such skill, that in spite of the destruction of the softer organs thousands of years ago, they have been enabled to make out the structure of the intes tinal tube! It has been shown that this was formed exactly like an Archimedian screw, and was strictly analogous to that of our sharks and rays. At the same time the nature of the food of these voracious reptiles has been discovered. The petrified remains of food which were found proved that they devoured an enormous quantity of fish, and even occasionally their own species, for small ichthyosauri have been met with, in the inclosed remains of the large ones.

Freaks of the Animal Kingdom.

With these terrible rulers of the ancient seas lived the plesiosauri, reptiles equally strange, and which Cuvier considered as the most singular races of the early world. They were remarkable for their turtle-like fins, and especially for the thinness and extreme length of their serpent-like necks. The arrangement of the skeleton in the plesiosaurus indicates that it swam ordinarily on the surface of the waves, curving back its long flexible neck like a swan, and darting forward with it from time to time in order to seize the fish which approached it. Their paws, similar to those of the sea turtles, show that the plesiosauri, like these reptiles, sometimes issued from the sea and sought refuge amid the plants, in order to evade their dangerous enemies, which were beyond all doubt the ichthyosauri.

If any of the animals which the remote periods of the globe present to our notice are to be looked upon as monsters, we submit that in this respect the first place is due to the pterodactyli, which remind one of the ancient dragons of legendary tradition. Their structure is so strange that one does not really know where to place them; they were alternately looked upon as birds, mammals, and reptiles. De Blainville, embarrassed, as indeed all the learned world were, formed a separate class for them in the animal kingdom. The aspect of the pterodactyl was necessarily very strange. When naturalists tried to restore their frames, the figures they produced were more like the offspring of some diseased imagination than realities. They were really reptiles furnished with large wings, and resembled enormous bats, having a very pointed head supported on a slender neck.

At the period in the history of the world when the ocean swarmed with such monsters as the ichthyosaurus, the land was tenanted by huge crocodile-like lizards. These were reptiles provided with feet; while those inhabiting the sea were partly like fishes, and had paddles to enable them to swim. The largest of the land species was the iguanodon, so called because it resembled in structure, and in the character of its teeth, the iguana, a lizard common in the tropical parts of America. The iguana of the present day only grows to the length of four or five feet, while the iguanodon of former ages reached astonishing dimensions. The small horn on its nose gave it a strange, dragon-like aspect; but, notwithstanding its enormous size and formidable look, it was probably a harmless creature, like its modern relative, feeding only on vegetable substances. A Terrible Monster.

The megalosaurus, or "great lizard," was, on the other hand, a dreadful carnivorous monster, almost as huge as the iguanodon, but far more terrible; for its immense jaws look as if they could have crushed through a bar of iron, and its formidable rows of teeth were specially adapted for cutting and tearing flesh: for some were arranged like those of a saw, while others were curved backward like a sabre, and sharp all along the inner edge, so that when an animal was seized by them it could not possibly escape. The body of the megalosaurus was covered with strong plates like armor, and its legs were longer in proportion to its size than those of other lizards. As these monsters were not sluggish like the crocodile and alligator, but, from their flexible, lizard-like structure, probably swift and sudden in their motions, the destruction of animal life by such must have been immense; and, indeed, their voracity may have been one cause of their extinction, for when other food failed them they may have attacked each other, the large herbivorous animals, such as the mastodon and mammoth, not being then in existence. From the plants preserved in the same rocks which contain the remains of these creatures, we know that they must have lived in a tropical climate, for the vegetation chiefly consists of tree-ferns and palms, such as only grow in hot countries.

The megalosaurus received its name from its gigantic size, although the size is, in some respects, the character of least importance. The tribe of lizards, one of the most important of the existing reptilian groups, forms a link in the chain by which the animal we are now describing was connected with known forms; but, although analogies unquestionably exist between the lizard and the megalosaurus, and also between this animal and the crocodiles, there yet remain marked and peculiar features separating it from both. It is now considered as one of an extinct family,