278 COSMOS. 



rium, missniium, and the megatlierides, among which is 

 Owen's sloth-like mylodon, eleven feet in length.* Besides 

 these extinct families, we find the fossil remains of still extant 

 animals, as the elephant, rhinoceros, ox, horse, and stag. The 

 field near Bogota, called the Ca^njoo de Gigantes. which is 

 filled with the hones of mastodons, and in which 1 caused ex- 

 cavations to be made, lies 8740 feet above the level of the 

 Bea, while the osseous remains, found in the elevated plateaux 

 of Mexico, belong to true elephants of extinct species. t The 

 projecting spurs of the Himalaya, the Sewalik Hills, which 

 have been so zealously investigated by Captain CautleyJ and 

 Dr. Falconer, and the Cordilleras, whose elevations are, prob- 

 ably, of very different epochs, contain, besides numerous mas- 

 todons, the sivatherium, and the gigantic land tortoise of the 

 primitive world (Colossochelys), which is twelve feet in length 

 and six in height, and several extant families, as elephants, 

 rhinoceroses, and giraffes ; and it io a remarkable fact, that 

 these remains are found in a zone which still enjoys the same 

 tropical climate which must be supposed to have prevailed at 

 the period of the mastodons.^ 



Having thus passed in review both the inorganic formations 

 of the earth's crust and the animal remains which are con- 

 tained within it, another branch of the history of organic life 

 still remains for our consideration, viz., the epoch of vegcta 

 tion, and the successive floras that have occurred simul- 

 taneously with the increasing extent of the dry land and the 

 modifications of the atmosphere. The oldest transition strata, 

 as we Jbave already observed, contain merely cellular marine 

 plants, and it is only in the devonian system that a few cryp- 

 togamic forms of vascular plants (Calamites and Lycopodi- 

 acese) have been observed. II Nothing appears to corroborate 



* [See Mantell's Wonders of Geology, vol. i., p. 168.]— Tr. 



t Olivier, Ossemens Fossiles, 1821. t. i., p. 157, 261, and 264. See, 

 also, Humboldt, Ueber die Hochebene von Bogota, in the Devtschen 

 Vierteljahrs-schrift, 1839, bd. i., s. 117. 



t [The fossil fauna of the Sewalik range of hills, skirting the south- 

 ern base of the Himalaya, has proved more abundant in genera nnd 

 species of mammalia than that of any other I'egioii yet explored. As 

 a general expression of the leading features, it may be stated, that it 

 appears to have been composed of representative forms of all ages, 

 from the oldest of the tertiary period down to the modern, and o{ all tht 

 geographical divisions of the Old Continent groupe<l tofjether into Oiie 

 comprehensive fauna. Fauna Antiqita Sivalicnsis, by Hu^h Falconer. 

 M.D., and iMajor P. T. Oautley.]— Tr. 



§ Journal of the Asiatic Society, 1844, No. 15, p. 109. 



II Beyrich, in Karsten's Archivfar Mlneralogie, 1844. bd. xviii., s. 218 



