296 FOSSIL GEOLOGY OP UNITED STATES. 



mus), two species of elephant (elephas primigenius), 

 the megatherium, megalonyx (Jeffersonii), three spe- 

 cies of the ox family, the fossil elk, and the walrus. 

 Of living species found fossil there are the horse, 

 bison, and three or four species of deer. The sit- 

 uations in which these have been found have been 

 either very recent undisturbed alluvial bogs, or a 

 slightly-disturbed marshy deposite, like Big Bone 

 Lick, neither of them covered by the general dilu- 

 vium ; thirdly, boggy beds containing lignite referri- 

 ble to an ancient alluvium, covered by diluvial sand 

 and gravel ; and, lastly, the floors of caves, buried 

 to a very small depth with earth not described. 



The largest collections of bone-remains occur in 

 boggy grounds called licks, affording salt, in quest 

 of which the herbivorous animals, wild and domes- 

 tic, enter the marshy spot and are sometimes mired. 

 The most noted of these spots is Big Bone Lick, in 

 Kentucky, occupying the bottom of a boggy valley, 

 kept wet by a number of salt-springs, which rise 

 over a surface of several acres. The spot is thus 

 described by Mr. Cooper : " The substratum of the 

 country is a fossiliferous limestone. At the lick 

 the valley is filled up, to the depth of not less than 

 30 feet, with unconsolidated beds of earth of va- 

 rious kinds. The uppermost of these is a light 

 yellow clay, which, apparently, is no more than the 

 soil brought down from the high grounds by rains 

 and land-floods. In this yellow earth are found 

 along the water-courses, at various depths, the 

 bones of buffaloes and other modern animals, many 

 broken, but often quite entire. Beneath this is an- 

 other thinner layer of a different soil, bearing the 

 appearance of having been formerly the bottom of 

 a marsh. It is more gravelly, darker coloured, 

 softer, and contains remains of reedy plants, smaller 

 than the cane so abundant in some parts of Ken- 

 tucky, with fresh- water mollusca. In this layer, and 

 sometimes partially imbedded in a stratum of blue 



