830 M E G M E H adapted for the support of immense claws, the middle one being especially large. The outer or fifth digit has no claw, and it may be considered as certain that the weight of the foot was, in standing and walking, chiefly thrown upon this, and that it was protected by a callous pad below as in the existing great Anteater, while the other toes were curved inwards towards the palm, only coming in contact with the ground by their outer surfaces. The mechanical arrangements by which the weight of the body was thrown entirely upon the outer side, of the foot are very curious, and are fully described in Professor Owen s memoir. The pelvis is remarkably wide, even more so than that of the Elephant, but it is formed on the same principle as in the Sloths. The femur is extremely broad and flattened ; the tibia an.l fibula are short and strong, and united together at each end. The hind foot, contrary to the usual rule in the Edentata, is even more singularly modified than the hand. The ankle-joint is formed upon a peculiar plan, quite un like that of the Sloths, or of any other mammal, except the Megatherium s nearest allies. The calcaneum projects nearly as far backwards as the fore part of the foot does forwards. There is no trace of great toe or hallux, or of its corresponding cuneiform bone. The second toe is rudimentary. The third has an enormous ungual phalanx, which, like those of the hand, is remarkable for the immense development of the bony sheath which is reflected from its proximal end around the base of the claw. The two outer toes have large and very peculiarly-shaped meta- tarsals, but only small phalanges, and no claws. The creature probably walked upon the outer edge of the sole, so that the great falcate claw of the third toe did not come into contact with the ground, and so was kept in a state of sharpness ready for use. The foot was therefore formed upon quite a different principle from that of the Anteaters or Sloths, though somewhat like the latter in having two of the toes aborted. Taking all the various points of its structure together, they clearly indicate affinities both with the existing Sloths and with the Anteaters, the skull and teeth more resembling those of the former, and the vertebral column and limbs the latter It is also not difficult to infer the food and habits of this enormous creature. That it was a leaf-eater there can be little doubt, but the greater size and more complex structure of its teeth might have enabled it to crush the smaller branches as well as the leaves and succulent shoots which form the food of the existing Sloths. It is, however, very improbable that it climbed into the branches of the trees like its diminutive congeners, but it is far more likely that it obtained its subsistence by tearing them down with the great hook-like claws of its powerful prehensile fore limbs, being easily enabled to reach them by raising itself up upon the massive tripod formed by the two hind "feet, firmly fixed to the ground by the one huge falcate claw, and the stout, muscular tail. The whole conformation of the hinder part of the animal is strongly suggestive of such an action. There can also be little doubt but that all its movements were as slow and deliberate as those of its modern representatives. An idea at one time prevailed that the Megatherium was- covered externally with a coat of bony armour like that of the Armadillos, but this originated in dermal plates belonging to the Glyptodon, a totally distinct animal, having been accidentally associated with bones of the Megatherium. Similar plates, on a smaller scale, have indeed been found in connexion with the skeleton of both Mylodon and Scelidotherium, animals of the same family, but never yet with the Megatherium, which we may therefore imagine with a covering of coarse hair like that of its nearest living allies, the Sloths and Anteaters. Bibliography. J. Garriga and J. B. Bry, Description del esquc- leto de un cuadrupedo muy corpulento y raro, que se conserva en el Eeal Gabinete de Historia Natural de Madrid, con 5 laminas, fol., 1796; G. Cuvier, in Annales du Museum, vol. v. p. 376, 1804; Pander and D Alton, Das Riescnfaulthier abgebildet und beschriebcn 1821 ; R Owen, "On the Megatherium," in Philosophical Trans- actions for 1851, 1855, 1856, and 1858, republished as a separate work in 1861 ; J. Leidy, " Memoir on the Extinct Sloth Tribe of North America, " Smithsonian Contributions to Knowledge, vol. vii., 1855 ; H. Burmeister, Description physique de la JtipubUque Argentine, t. iii. pt. 1, "Mammiferes vivauts et eteints," 1879 p 285. (W. H. F.) MEGHNA, a river of India, forming, in the lower part of its course, the great estuary of the Bengal delta, which conveys to the sea the main body of the waters of the Ganges and the Brahmaputra, which unite at Goalanda in Farfdpur district. The united waters thence roll south a mighty river of great depth and turbidness, sometimes split up into half a dozen channels by sand-banks of its own formation, sometimes spreading out into a widespread sheet of water which the eye cannot see across. The river enters tha sea by four principal mouths, enclosing the three large islands of Dakshin Shahbazpur, Hatia, and Sandwip. It is navigable by native boats of the largest burden, and also by river steamers, all the year through ; but the navigation is difficult, and sometimes dangerous, on account of shifting sand-banks and " snags," and boisterous weather when the monsoon is blowing. The most favourable season for navigation is between November and February. Alluvion and diluvion are constantly taking place, especially along the seaboard, and in Nodkhalf district the land is said to have advanced seawards 4 miles in twenty-three years ; while the islands fringing tlie mouth are annually being cut away and redeposited in fresh shapes. The tidal phenomena of the Meghnd surpass those of any other Indian river. The regular rise of the tide is from 10 to 18 feet, and at springs the sea rushes up in a single wave, known as the "bore," on the Meghna a justly dreaded danger to boatmen, It is greatest at the time of the biennial equinoxes, when navigation is sometimes impeded for days together. The tidal wave is suddenly beheld advancing like a wall topped with foam of the height of nearly 20 feet, and at the rate of 15 miles an hour; in a few minutes all is over, and the river has changed from ebb to flood tide. A still greater danger is the " storrn wave," which occasionally sweeps up the Meghna in the shape of cyclones. The latest and most destructive of these disasters were those of May 1867 and October 1876, when the whole islands and sea-face of the mainland were entirely submerged. In the latter calamity it has been officially estimated that about 19 per cent, of the popula tion in the mainland portion of Noakhalf, and in the islands of Sandvvip and Hatia, were drowned, and that a like proportion subsequently died of cholera and other diseases caused by the results of the storm. MEHADIA, a market-town in the county of Szoreny, Hungary, is situated on the Bella-Reka, or Bereka, 13^ miles north of Orsova, in 44 55 N. lat., 22 22 E. long". The town is small but thriving, and contains Greek Orthodox and Roman Catholic churches, the ruins of a castle, and some interesting Roman antiquities. Mehadia is, however, chiefly of importance as the station for the Hercules Baths, distant about 3 miles east from the town, and situated in a narrow pass in the romantic valley of the Cserna. Of the twenty-two hot springs of Mehadia, nine are now in use, the most powerful one being the Hercules, which yields about 5000 cubic feet of water per hour. The springs are all strongly impregnated with salts of sulphur, iodine, bromine, and chlorine, and their average temperuture is 70 to 145 Fahr. They are much used for chronic rheumatism, gout, and cutaneous eruptions, and,
during the season, which usually lasts from the middle of