Page:Encyclopædia Britannica, Ninth Edition, v. 15.djvu/861

Rh M E G M E G 829 enrolled themselves among the allies of Sparta. They suffered terribly during the Peloponnesian War : Athenian ships blockaded their harbours and Athenian armies ravaged their land once or twice every year. The long famine in the city is referred to by Aristophanes in the Acharnians. The city maintained a flourishing existence throughout the Greek and Roman periods, but played a very subordinate part in history. In the unsettled time when the Roman empire had decayed, it was often plundered by pirates. As regards literature, Megara s chief distinction, besides the poems of Theognis and the comedy of Susarion, was the school of philosophy founded there by Euclid, a disciple of Socrates. The coinage of the city is a very con&amp;lt; fused and difficult subject ; no very early coins can be with certainty attributed to it. The usual types are Apolline. The topography is described by Pausanias, bk. i. Megara is about four hours carriage-drive from Athens. MEGATHERIUM is the name given by Cuvier to a large extinct animal belonging to the order Edentata (see MAMMALIA, p. 334). A nearly complete skeleton, found on the banks of the river Luxan, near Buenos Ayres, and sent in 1789 to the Royal Museum at Madrid, long Skeleton of the Megatherium, from the specimen in the Museum of the Royal College of Surgeons of England, x ^j. remained the principal if not the only source of infor mation with regard to the species to which it belonged, and furnished the materials for many descriptions, notably that of Cuvier, who determined its affinities with the Sloths. 1 In 1832 an important collection of bones of the Megatherium were discovered near the Rio Salado, and were secured for the museum of the College of Surgeons of England, and these, with another collection found at Luxan in 1837, and now in the British Museum, supplied the materials for the complete description of the skeleton published by Professor Owen in 1881. Other skeletons have subsequently been received by several of the Conti nental museums, as Milan and Paris, and, consequently, our knowledge of the organization of the Megatherium, so far as it can be deduced from the bones and teeth, is as complete as that of any other animal, recent or extinct. The remains hitherto spoken of are all referred to one species, Megatherium americanwn of Blumenbach, M. cuvieri 1 An excellent figure of this skeleton, which unfortunately was incorrectly articulated, and wanted the greater part of the tail, was published by Pander and D Alton in 1821, and has been frequently reproduced in subsequent works. of Desmarest, and are all from the newest or post-Tertiary geological formations of the Argentine Republic and Paraguay, or the lands forming the basin of the Rio de la Plata. Dr Leidy has described, from similar formations in Georgia and South Carolina, bones of a closely allied species, about one-fourth smaller, which he has named M. miralile. A third species, M. laurillardi of Lund, is founded upon remains found in Brazil. The following description will apply especially to the best-known South American form, Megatherium ameri- canum. In size it exceeded any existing land animal except the elephant, to which it was inferior only in con sequence of the comparative shortness of its limbs, for in length and bulk of body it was its equal, if not superior. The full length of a mounted skeleton from the fore part of the head to the end of the tail is 18 feet, of which the tail occupies 5 feet. The head, which is small for the size of the animal, presents a general resemblance to that of the Sloth ; the anterior part of the mouth is, however, more elongated, and the malar bone, though branched posteriorly in the same way as that of the Sloth, meets the zygomatic process of the squamosal, completing the arch. The lower jaw has the middle part of its horizontal ramus curiously deepened, so as to admit of implantation of the very long- rooted teeth. In number the teeth exactly resemble those of the Sloths, being five above and four below on each side, and they are limited to the lateral parts of the mouth, front teeth being entirely wanting. They resemble those of the Sloths nlso in their persistent growth, and in their composition of three tissues vaso-dentine, true dentine, and cement ; but they are of prismatic or quadrate form, and the con stituent materials of different densities are so arranged that, as they wear, two trans verse ridges of hard dentine remain at a greater elevation than the rest of the tooth, producing a very efficient figs. 35 and 3G, article MAM- 385). The vertebral column consists of seven sixteen dorsal, three lumbar, five sacral, and caudal vertebrae. The spinous processes are triturating apparatus MALIA, p cervical, eighteen (see much better developed than in the Sloths, and are all directed backwards, there being no reversing of the in clination near the posterior end of the dorsal series, as in most active-bodied mammals. In the lumbar region, the accessory zygapophyses, rudimentary in Sloths, are fully developed, as in the Anteaters. The tail is large, and its basal vertebrae have strong lateral and spinous processes and chevron bones, indicating great muscular development. The scapula resembles that of the Sloths in the union of the acromion with the cora- coid, and in the bridging over of the supra-scapular notch. The clavicle is complete and very large much resembling that of man on a large scale. The fore limbs are longer than the hind limbs. The radius and ulna are both well- developed, and have a considerable amount &amp;gt;o f freedom of movement. The hand is singularly modified, dio-it is represented only by a rudimentary metacarpal, but the next three are large, and terminate in phalanges