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MEL 



high, its haunches five feet wide, 

 its feet a yard in length, and its 

 body twelve feet long : it united 

 part of the structure of the arma- 

 dillo with that of the sloth. The 

 relative proportions of the extremi- 

 ties of the megatherium differ 

 greatly from those of the sloth, 

 and indeed from those of any known 

 animal. Its teeth prove that it 

 lived on vegetables, and its fore- 

 feet, robust, and armed with sharp 

 claws, show that roots were its 

 chief objects of search. Its hide 

 appears to have been covered with 

 a bony coat of armour of consider- 

 able thickness, the use of which 

 was probably defensive, not only 

 against the sharp claws of beast of 

 prey, but also against the myriads 

 of insects that surrounded it. Its 

 tail was long, and composed of 

 vertebra of enormous magnitude, 

 the body of the largest being seven 

 inches in diameter, and the hori- 

 zontal distance between the ex- 

 tremities of the two transverse 

 processes, being twenty inches. If 

 to this be added the thickness of 

 the muscles and tendons, and of 

 the shelly integument, the diameter 

 of the tail, at its largest end must 

 have been at least two feet; and 

 its circumference, supposing it to 

 be nearly circular, about six feet, 

 secure within the panoply of his 

 defensive armour, where was the 

 enemy that would dare encounter 

 this behemoth of the Pampas? a 

 creature whose giant carcase was 

 encased in an impenetrable cuirass, 

 and who, by a single pat of his 

 paw, or lash of his tail, could in an 

 instant have annihilated the couguar 

 or the crocodile. The genus me- 

 gatherium comprehends two species, 

 the megatherium, properly so called, 

 and the megalonyx. 

 MEI'ONITE. (from peiwv, less, Gr.) 

 The Meionit of Werner. A mine- 

 ral, thus named from its termina- 

 ting pyramids being lower than those 



of similar forms in other minerals. 

 Meionite is a prism ato-pyramidal 

 felspar. It occurs in grains, or 

 small crystals, whose more common 

 form is an eight-sided prism, trun- 

 cated on its lateral edges, and ter- 

 minated by four low-sided pyramids. 

 It is of a greyish- white colour; 

 translucent, and sometimes trans- 

 parent. It scratches glass, and 

 before the blow-pipe readily melts 

 into a white spongy glass. It 

 is found at Mount Somma, near 

 Vesuvius. 



MELA'NIA. (from /ieXas, black, Gr.) 

 A genus of univalve fresh-water 

 shells belonging to the order Pec- 

 tinibranchiata, class Mollusca. The 

 melania is a turreted univalve ; the 

 aperture entire, ovate, or oblong, 

 and spread out at the base of the 

 columella, which is smooth. Recent 

 melania3 are found in rivers and 

 estuaries. Fossil melaniae are found 

 in the environs of Paris. 



ME'LANITE. (from yiieXas, black, Gr.) 

 The Melanit of Werner; Grenat 

 noir of Haiiy ; Grenat melanit of 

 Brongniart. A velvet black, 

 opaque, dodecahedral variety of 

 garnet. It occurs in crystals, 

 which are dodecaedrons, with trun- 

 cated edges. Fracture conchoidal. 

 Specific gravity 3 '73. Its con- 

 stituents are silex 3S f 5, lime 32*5, 

 oxide of iron 25'25, alumine 6, 

 oxide of manganese '04. It is 

 found at Frascati, near Mount 

 Vesuvius, in Bohemia, and in 

 JSTorth America. 



MELANO'PSIS. A genus of oval or 

 oblong, fusiform, univalves, be- 

 longing to the family Melaniana, 

 in Lamarck's arrangement. M^ela- 

 nopsides are found both recent and 

 fossil ; they are distinguished from 

 Melanias by a notch in the aperture. 

 Fossil melanopsides are found in 

 the shale of the Wealden, at 

 Pounceford. 



ME'LAPHYB. j A compact, fine- 



ME'LAPHYBE. j grained, dark 



