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from which they differ by the absence of the hooks in their crests.

What is further known concerning the osteology of the lophiodons indicates manifest affinities with the tapirs, rhinoceroses, and in some particulars, with the hippopotamuses. There are several species of them; the whole remains of which are found enveloped in beds containing exclusively freshwater shells; associated with amphibious animals, such as the crocodile and trionyx, which now inhabit the freshwaters of hot countries; but in a few places, these remains are covered with a stratum undoubtedly of marine formation.

This is of all the fossil animals of very great size, the most lately discovered, and hitherto the rarest ; and yet it is the one whose osteology was first completely understood, in consequence of all its bones being found assembled in one place, and of their being immediately mounted into a skeleton with the utmost care. To the praise of the Spaniards it

must be said, that they first gave this useful lesson, since followed by Mr. Peale in the American Mastodonte, and by Mr. Adams in the Siberian elephant.

From the publication of Don Joseph Garriga, it appears that Spain has been long in possession of considerable portions, of at least three different skeletons. The first and most complete is that in the Royal Cabinet of Madrid. It was sent thither in the course of September 1789, by the Marquis de Loretto, viceroy of Buenos Ayres, with a notice intimating that it had been found in excavations made on the borders of the river Luxan, a league south-east of the city of the same name, which itself is 3 leagues to the west-south-west of Buenos Ayres. The soil in which it was found is raised only about 36 feet above the level of the water. A second skeleton arrived in 1795, at the same Cabinet, sent thither from Lima; and a third, which father Fernando Scio of the pious schools possessed, had been presented to him by a lady returning from Paraguay. These two cannot now be found.

The first animal of 1789 was mounted up by Jean-Baptiste-Bru prosecteur of the Royal Cabinet of Madrid, who delineated the entire figure of it, and its different parts in five plates which he got engraved, and published with a minutely detailed description. In 1818 the megatherium was inspected by a Livonian anatomist and a German draughtsman conjointly, who published at Bonn in 1821 an exact description and representation of the skeleton.

The first glance at its head lays open to us the most marked relations with the structure of the sloths and their aï species of Buf fon. The most striking point of resemblance is the long descending apophysis on the cheek, placed at the anterior base of the zygomatic arcade. This is as long in proportion in the aï, as in the megatherium, but in the latter it has a more upright direction. The fossil has also the arcade in one piece, whilst it is discontinuous in

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both species of sloths even when full grown; however traces may still be seen in the arcade of the megatherium of the structure peculiar to sloths.

The long oblique process which rises from the upper edge of the arcade exists also in the aï. The multitude of holes and little canals with which the front part of the fossil muzzle is riddled, would allow vessels and nerves to pass through proper for cherishing a considerable organ like a proboscis, which must however have been very short, seeing the length of the neck. As the head has a moderate size and carries no tusks, a long neck was not so injurious as it would be in the elephant.

The grinder teeth amount to four on each side, both of the upper and under jaw, and like those of sloths, have a prismatic form and crown traversed by a furrow. The sloths have one tooth more in the upper jaw. The former have two roots, the latter a single one.

If the number of seven vertebræ seen in the neck of this skeleton be real, as the analogy of other quadrupeds would make us readily believe, the megatherium will differ much in this respect from the sloth aï, which deviates in its nine cervical vertebræ from all kown quadrupeds. There are in the megatherium sixteen dorsal vertebræ and consequently sixteen ribs on each side, and there are three lumbar vertebræ. This is exactly the number in the aï. The relative proportion of the extremities is not the same as in the sloths, which have the forelegs double the length of their hind legs. Here that inequality is much less. On the other hand the disproportionate thickness of the bones of the thigh and leg, which begin to be visible in the sloth, the armadillo, and especially the pangolin or short-tailed manis, is carried in the fossil skeleton to an excessive degree, the thigh bone having a length only double of its greatest thickness, which makes it grosser than any animal known, even the great mastodonte of the Ohio. This general disposition of the extremities leads us to judge that this animal had a slow and regulated gait, and that it advanced neither by running nor by leaping, as animals which have their forelegs shorter than the hind ones, nor by creeping, like those with relatively long hind legs, as the sloths; which the megatherium otherwise so much resembles.

The shoulder blade alone would indicate the family of the animal, and the genus to which it is most allied. It has not only, on a

great scale, the same proportions as the sloths, but it exhibits also the round hole observable in this genus, as well as in the middle ant-eater (tamandua); and further it possesses in common with the sloths this character unknown elsewhere among the mammifera, that its acromion process is prolonged in form of an arc, and goes forwards to join itself with the coracoid beak, affording through it an articulation with the clavicle. The presence of clavicles removes the megatherium considerably from all the quadrupeds which might be confounded with it on account of its huge size, as the elephant, rhinoceros, and all the large ruminating animals, none of which possess these bones.

The humerus (shoulder-bone) of the megatherium is very remarkable by the breadth of its lower end, arising from the great surface of the ridges placed above its condyles. We thereby see that the muscles attached to it, and which served to move the palm and the toes, must have been very considerable;—a new proof of the great use this animal made of its anterior extremities. In like manner this great breadth of the bottom of the humerus is also found in the ant-eater, which is known to employ its enormous claws for suspending itself to trees, or for digging up the solid nests of termites. In it, the breadth is three-fifths of the length, while it is only one-half in the megatherium ;-the proportion of the scaly ant-eater with a long tail or the phatagin (Manis tetradactyla Lin.). In the rhinoceros this breadth is only onethird, and in the elephant one-fourth of the length. In the ruminating animals, which make almost no use of their toes, these ridges nearly disappear.

Thus the affinities of our fossil begin to extend. From a head and a shoulder-blade almost exactly like a sloth, we have come to a humerus nearly of an ant-eater.

The basin resembling in its enormous size, that of the elephant and rhinoceros, indicates that the megatherium had a large belly in accordance with the form of its grinder teeth, and shows that it lived on vegetable substances. The thigh bone is too large for comparison with any other animal. The nearest is that of the rhinoceros, but this differs in having a third trochanter, which is wanting in the fossil thigh, giving it a close analogy in form with that of the pangolins.

The inspection of a skeleton so complete, and

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fortunately preserved, enables us to form conjectures somewhat plausible on the nature of the animal to which it had belonged. Its teeth prove

that it lived on vegetables, and its robust fore-feet, armed with sharp claws, testify that it was chiefly their roots which it sought after. Its magnitude, and its talons, supplied it with abundant means of defence. It was not swift in running, but this was unnecessary, as it had no occasion either to pursue or to fly. It would therefore be difficult to find in its organization alone the causes of the final destruction of the genus; and yet if it still exists, where can it be? How can it have escaped all the researches of hunters and naturalists? Its analogies approximate it to different genera of the edental or toothless family of animals. It has the head and shoulder of a sloth-a creature possessing both tusks and grinders; while its limbs and its feet exhibit a singular mixture of characters belonging to the ant-eaters and the armadillos. It has no analogy whatever with the felis or tiger tribe. The wood-cut represents exactly the form of its skeleton, which is fully 13 feet long from the muzzle to the coccyx, and 9 feet high at the saddleseat. The term megatherium signifies a huge wild beast.

XI. The megalonyx is another large fossil animal of the edental family, of which, however, only a few bones were found at a depth of two or three feet, in a cavern of the county of Green Briar, in the south-west of Virginia. The district is calcareous, and consequently similar to that of the mineral strata of Germany and Hungary, where the famous