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the same manner that sea-water now does, might be safely inferred from such parts of the ocular apparatus of the fossil reptiles and fish as are still preserved to us, although the soft parts of the eye are, of course, absent. But in the Trilobites, those most ancient and extinct crustaceans which inhabited the bottom of the old seas, we have the eye itself petrified; and this, when compared with the similar compound eyes of the Serolis and Limulus, or King Crab, which now exist, proves, as Dr. Buckland has pointed out, that, the visual organs of both were fashioned for media essentially the same, and entirely dispels the dream of those geologists who believed that a turbid chaotic fluid holding in solution the precipitates from which the earth's crust was deposited, then prevailed.

In the same sea wherein the Ichthyosaur and Plesiosaur took their pastime, swam shoals of the finny tribe, now extinct and potted in their ancient mud,-among them the great Sauroid fishes, which must have almost disputed the mastery with some of the younger branches of the enaliosaurian families. Starfishes, or Ophiuri, not unlike those which at present occur on our shores; crinoideans, or stone-lilies as the collectors term them; and extinct crustaceans, organized, however, in the same manner as existing species, were present; Belemnites and Cornua Ammonis, which have left no living representative, and Orthocerata, with numerous other testaceous mollusca, were there, to say nothing of turtles; so that the ancient and respectable enaliosaurian corporation must have fared sumptuously; and, certainly the Ichthyosaurian branch of it had a more than aldermanic development of the mouth-and-stomach power.

The enaliosaurians, Professor Owen observes, are immediately connected with the crocodilian reptiles by the extinct and gigantic Pliosaurus, which is more closely allied to the true Saurians, and whose remains occur in the Kimmeridge and Oxford clays. The teeth are remarkable for their thickness and strength, and the cervical vertebræ for their shortness, the enormous jaws having been wielded by a neck, if neck it may be called, as short and strong as that of the whales.

But there were other sea-dragons besides the enaliosaurians, framed, however, upon a somewhat different principle, and according to the Lacertian type, such as the Mosasaurus or great animal of Maastricht.

This marine giant appears to have been most nearly allied to the Monitory lizards, as they are called, which now frequent the river-sides and marshy places in warm countries, and have had the credit, not very deservedly, we believe, of warning the traveller, by a peculiar whistling sound, of the approach of cro

codiles and their congeners. Five feet is a great length for an existing Monitor to attain; but the Mosasaur must have reached twenty-five feet. The noble head in the Paris Museum, of which we have casts in this country, is four feet long: that of a large existing Monitor does not measure more than five inches in length.

The fossil was found in the calcareous freestone, near Maastricht, the most recent deposit of the cretaceous formation, in company with Ammonites, Belemnites, and other organic remains of the chalk formation in 1780, and for some time adorned that city. But it was a very sphinx's riddle to the learned. Some thought it was an enormous crocodile; others would have it to be very like a whale; but at last Camper suggested, and Cuvier afterwards confirmed its true zoological relations.

Fancy a marine Monitor of the length and bulk of a Grampus, with four paddles instead of legs, and a high and deep oar-like tail formed for propelling the animal through the wave, instead of the long and slender tail of the living species-and you have some notion of the Mosasaur.

Its jaws and teeth were tremendous. Nothing comparable to them can be imagined, excepting the ancient caricature, which may be known to some of our readers, representing a learned gentleman in his robes, not quite at his ease, between a pair of Saurian jaws, worthy of Munchausen's creation, and underwritten,

A LAWYER AND A SAWYER.

The rush of the Mosasaur through the water must have been most rapid; and its whole structure bespeaks an agent for keeping down the larger races of ancient fishes, more active and destructive than the great Ichthyosaur itself.

The Paris specimen belonged to the collection of Hoffman, from whom it was said to have been taken by the chapter of Maastricht, by virtue of some droits vested in them, and was given up by the Dean to the French army when it invested the city. Fortunate was the inhabitant whose dwelling lay near the place where the head of the Mosasaur was deposited: for the story goes, that to prevent the possibility of injury to a prize, which the besiegers were determined to possess, the French cannoniers were enjoined not to point their artillery towards that part of the city which held the remains of this grand Sea-Dragon.

ANCIENT AMPHIBIOUS AND TERRESTRIAL

DRAGONS.

"Through many a dark and dreary vale

They passed, and many a region dolorous,

Rocks, caves, lakes, fens, bogs, dens, and shades of death."

PARADISE LOST.

Ir, with the eyes of the imagination aided by the lights afforded by the strata and the ancient inhabitants buried therein, we look back upon our earth when the forms of crocodilian reptiles first came upon it, we may picture to ourselves an oozy, spongy, reeky land, watered with wild rivers, and largely overspread by a vast expanse of lakes, on whose dreary, slimy banks gigantic crocodiles reposed amid enormous extinct bog-plants, or floated log-like in the fenny sunshine on their waters, while the silence of the desolate scene was broken by the clank of their monstrous jaws, as they ever and anon closed upon the bygone generations of fishes, or by the growlings and explosions of the distant volcano.

With, perhaps, one exception-the crocodile of the Ganges namely-none of the ancient crocodilians exhibit specific identity with the alligators, crocodiles, and gavials now existing. And while they differ from the present races, the modifications of their osseous structure in which they so vary, as well as from each other, are much greater than any of those by which the skeletons of the existing species differ among themselves.

"Not only," says Professor Owen, "do the form and proportions of the peripheral parts, as of the jaws, the teeth, and the locomotive extremities vary, but the spine or central axis of the skeleton, offers modifications of the articular surfaces of the component vertebræ, which are quite unknown in the alligators, crocodiles, and gavials of the present epoch. In these existing species the anterior surface of the vertebral centrum is concave,

the posterior convex, except in the atlas and sacrum. But besides this mode of junction, Cuvier has recognised in the crocodilians of the secondary formations two other types of vertebral structure in one of these the positions of the ball and socket are reversed; in the other, and more common modification, both the articular surfaces of the vertebra are flat or slightly concave. Remains of extinct crocodilians, exhibiting all the three systems of vertebral articulation, occur in English formations."

The professor then divides the extinct British species which, generally, agree with the existing crocodilians into two sections. First, those with concavo-convex vertebræ: secondly, those with biconcave vertebræ.

In the first of these divisions he notices and describes a single species-Crocodilus Spenceri.

In the second he arranges and gives a description of the following: Suchosaurus cultridens, Goniopholis crassidens, Teleosaurus Chapmanni, Teleosaurus cadomensis, Teleosaurus asthenodeirus, Steneosaurus rostro-minor, Poikilopleuron Bucklandi, Streptospondylus Cuvieri, Cetiosaurus brevis, Cetiosaurus brachyurus, Cetiosaurus medius, and Cetiosaurus longus.

The destructive nature of these ancient inhabitants of the swamps which once occupied the place of the fair fields and cities of these islands, may be imagined from the multitude of weapons that armed their jaws.

It has been calculated that Teleosaurus cadomensis had one hundred and eighty, and Teleosaurus Chapmanni at least one hundred and forty teeth. The gavial of these degenerate days cannot boast of more than one hundred and twelve.

But terribly voracious as these and other crocodilians, (the enormous Sewalik crocodilian for example*) must have been, their efforts in keeping down the animals of the ancient Fauna of Britain could only have been feeble compared with those leviathans the Cetiosauri, some of which, according to Professor Owen's well-grounded statement, must have rivalled the modern great whales in bulk, and which he holds-with reason, we think were strictly aquatic, and most probably marine in their habits. The larger alligator of the Ganges has been known in our own times to descend beyond the brackish water of the delta into the sea, though now frightened from its propriety by the steam-paddles that constantly vex that sacred

river.

The evidence from which Professor Owen comes to this con

* See the work of Dr. Falconer and Major Cautley above noticed, p. 321,

note.

clusion rests on the sub-biconcave structure of the vertebræ, and the coarse cancellous tissue of the long bones, which show no trace of a medullary cavity. In the great expanse of the coracoid and pubic bones, he tells us, as compared with the Teleosaurs and crocodiles, the gigantic saurians in question manifested their close affinity to the true Enaliosaurs which formed the principal subject of our last chapter; whilst their essential adherence to the crocodilian type is marked by the long bones of the extremities, especially the metatarsals, and above all, by the toes being terminated by strong claws.

The main organ of swimming is, the professor adds, shown by the strength and texture and vertical compression of the posterior caudal vertebræ, to have been a broad vertical tail; and the webbed feet, probably, were used only partially, in regulating the course of the swimmer, as in the puny Amblyrhynchus of the Gallapagos Islands.

But what is an Amblyrhynchus ?

There are terrestrial and marine Amblyrhynchi; but it is the aquatic species Amblyrhynchus cristatus, to which the professor alludes. Here is its portrait drawn by the master hand of Darwin :

"It lives exclusively on the rocky sea-beaches, and is never found, at least I never saw one, even ten yards inshore. It is a hideous-looking creature, of a dirty black colour, stupid and sluggish in its movements. The usual length of a full-grown one is about a yard, but there are some even four feet long: I have seen a large one which weighed twenty pounds. On the island of Albemarle, they seem to grow to a greater size than on any other. These lizards were occasionally seen some hundred yards from the shore, swimming about; and Captain Colnett in his voyage, says, 'they go out to sea in shoals to fish.' With respect to the object, I believe he is mistaken; but the fact stated on such good authority cannot be doubted. When in the water the animal swims with perfect ease and quickness, by a serpentine movement of its body and flattened tail, the legs, during this time, being motionless and closely collapsed on its sides. A seaman on board sank one with a heavy weight attached to it, thinking thus to kill it directly; but when, an hour afterwards, he drew up the line, the lizard was quite active. Their limbs and strong claws are admirably adapted for crawling over the rugged and fissured masses of lava which everywhere form the coast. In such situations, a group of six or seven of these hideous reptiles may oftentimes be seen on the black rocks, a few feet above the surf, basking in the sun with outstretched legs."

This extraordinary animal, notwithstanding its disgusting appearance, seems to be very harmless. Mr. Darwin found the

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