FROM THE PHOSPHATE BEDS OF SOUTH CAROLINA. 211 



tebi-ffi and teeth of large teleost Fishes, the dental pavements of Rays, fragments of 

 Turtle shells, vertebrse of Crocodiles, ear-bones and teeth of Cetaceans, bones of 

 Manatees, etc. With these likewise are found the remains of both extinct and 

 still existing terrestrial mammals, especially teeth and bone fragments of Elephant 

 and Mastodon, Megatherium, Horse, Tapir, Bison, and Deer. More rarely there 

 are found remains of Hipparion, Castoroides, Hydrochoerus, and of the smaller 

 and more common genera and species. 



The fossils mainly consist of the harder parts of the skeleton and of teeth, 

 usually more or less water-worn, indicating shallow seas and an active surf to 

 which they were exposed. Many of them exhibit the drilling effects of boring 

 mollusks, especially those which are supposed to have been derived from the tertiary 

 marl rock, the operation of drilling apparently having been performed both before 

 and during the time the fossils were imbedded in the rock. Only enamel or the 

 enamel-like dentinal layer such as is found investing the crown of the teeth of 

 Sharks, appears to have been a protection against the drilling power of the borers. 



Fossils excavated from the phosphate beds are of a ferruginous brown color, 

 but often much lighter or white upon the surface. Those which are obtained from 

 the rivers contiguous to the beds are usually more or less black, with the enamel 

 of teeth iron-gray, and they frequently exhibit the basal attachment of small bar- 

 nacles, and occasionally the valve of an oyster. 



From the fossils consisting mainly of the harder and denser, and therefore 

 heavier parts of skeletons and teeth, they are generally assumed to be petrified, 

 but usually the change has not been more than a moderate loss of the ostein basis 

 and the infiltration of iron oxyd. 



From the extraordinary variety and profusion of the fossil remains of the 

 Ashley phosphate beds it may be inferred that these were the former rich feeding 

 grounds for multitudes of marine and amphibious animals. At an early period 

 during the formation of the tertiary marl, here congregated great Sharks, Rays, 

 Squalodons, etc. At a later period their successors varied their diet with the car- 

 cases of great land animals, as Elephants, Mastodons, etc., which floated down the 

 broad and swollen rivers, as drowned herds of the Bison are said to do in our day 

 upon the Missouri River. 



Some of the remains of terrestrial animals, comparatively few in number, found 

 as fossils in the Ashley phosphate beds, including even the softer or more spongy 

 bones, exhibit no evidence of violent water action other than the signs of decay 

 from the combined influence of moisture and air; neither do such fossils exhibit 

 the marks of boring mollusks, nor the attachments of barnacles, Usuallv black 



