416 NATURAL HISTORY. 



and objects of human ai't, mingled with remains of fishea, reptiles, and mammals, 

 washed by the river from the banks, composed of eocene and post-pliocene 

 deposits. 



" Teeth of an extinct species of horse, however, undoubtedly belong as true fossils 

 to the post-pliocene formations in the vicinity of Charleston. These are usually, 

 hard in texture, stained brown or black from the infiltration of oxide of iron, 

 sometimes well preserved, but more frequently in a fragmentary condition and 

 water- worn. Generally they are not larger than the teeth of the more ordinary 

 varieties of the domestic horse, and sometimes are quite as simple in the plication 

 of their enamel, but usually are more complex and sometimes exceedingly so. 



*' One figured represents a first superior molar tooth, neither larger nor more com- 

 plex in structure than the corresponding tooth of the recent horse. This specimen, 

 which is dense and jet black in color, was obtained by Prof. Holmes from a stratum 

 of ferruginous sand, two inches thick, exposed on the side of a blufij on Goose 

 Creek, about twelve miles from Charleston. 



•' Having expressed a desire to see the locality from which the tooth just men- 

 tioned was obtained, Prof. Holmes afforded me the opportunity of doing so. The 

 blufi" is about thirty feet high; its base is formed of a pliocene limestone, about 

 fifteen feet thick, and composed of the debris of marine shells ; above this is the 

 stratum of ferruginous sand, of post-pliocene age, containing numerous pebbles 

 and rolled fragments of bone all blackened like the tooth obtained from the same 

 position. Overlying the latter stratum, there is a layer of stiflf blue clay, about 

 two feet in thickness, and above this there are about twelve feet of sand and 

 earth-naould. 



" A similar blackened tooth was obtained from the same formation at Doctor's 

 Swamp, John's Island. 



" Another figure represents a remarkably well preserved specimen of a lower 

 molar above referred to from Georgia, where it was discovered by J. H. Couper> 

 in association with equally well preserved remains of other extinct animals. The 

 tooth is brown in color, and it neither differs in size nor form from its homologue 

 in the recent horse. 



" In the collection of fossils of Prof. Holmes, there is the specimen of an upper 

 first laro-e molar, labelled from Texas, represented in figure 5. The tooth is of the 

 largest comparative size, and exhibits the highest degree of complexity in the fold- 

 ing of its enamel ; in both of which characters it differs in such a remarkable 

 (jgo-ree from the corresponding tooth, represented in figure 5, from the post-pliocene 

 formation of South Carolina, that it appears hardly possible that these two teeth 

 should belong to the same species of horse. 



" A remarkably well preserved specimen of an upper molar-tooth, jet black in 

 color and an incisor, yellow and quite friable in texture, both belonging to the 

 extinct horse, from North Carolina, have been submitted to my inspection by Prof. 

 Emmons. 



" Among the most interesting of the fossils discovered by Prof. Holmes, in the 

 post-pliocene beds of the Ashley River, are two molar teeth of a species of the 

 equine genus Eippotherium. These are the first remains of the latter discovered 

 in America, and they indicate the smalle8t|known species. 



