102 POST-PLEIOCENE FOSSILS. 



species of South America, under the name of Equus curvidens, Owen,* were obtained from 

 a pond in a marsh of Big-bone-lick, Kentucky, together with some bones of the existing 

 Bison, the Megahnyx, and the Mastodon. From their size, form, and condition of preser- 

 vation, I am now disposed to believe they are recent remains, which subsequently became 

 mingled with their older associates. 



Among a number of teeth of the Horse in Prof. Holmes' collection, labelled as coming 

 from the Post-Pleiocene deposit of Ashley river, there are several which from their size, 

 construction, and condition of preservation, I feel convinced are of recent date ; and these, 

 no doubt, became mingled with the true fossils of that formation, where it is exposed on 

 the Ashley river, in which position I personally found undoubted remains of the recent 

 Horse and other domestic animals, and objects of human art, mingled with remains of 

 fishes, reptiles, and mammals, washed by the river from the banks, composed of Eocene 

 and Post-Pleiocene deposits. 



Teeth of an extinct species of Horse, however, undoubtedly belong, as true fossils, to 

 the Post-Pleiocene 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 com- 

 plex, and sometimes exceedingly so. 



Figures 19-22, Plate XVI, represent four inferior molar teeth of the extinct Horse, which 

 were obtained by Prof. Holmes from an excavation of the Post-Pleiocene deposit of Ashley 

 river. The pair represented in figures 19, 21, exhibit a greater degree of plication in the 

 enamel than is usual in any of the lower molars of the Horse, whether recent or extinct ; 

 but the others present nothing peculiar. They range from two to three inches in length, 

 thirteen to fourteen lines in breadth, and seven to eight lines in width. 



Figure 8, Plate XV, represents a first superior molar tooth, neither larger nor more 

 complex 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 bluff, on Goose creek, about 

 twelve miles from Charleston. 



Having expressed a desire to see the locality from which the tooth just mentioned was 

 obtained, Prof. Holmes afforded me the opportunity of doing so. The bluff is about thirty 

 feet high; its- base is formed of a Pleiocene limestone, about fifteen feet thick, and com- 

 posed of the debris of marine shells ; above this is the stratum of ferruginous sand, of 

 Post-Pleiocene age, containing numerous pebbles and rolled fragments of bone, all black- 

 ened, like the tooth obtained from the same position. Overlying the latter stratum there 

 is a layer of stiff blue clay, about two feet in thickness, and above this there are about 

 twelve feet of sand and earth mould. 



* Proc. Acad. Nat. Sci., Phila., Ill, 184?, 622. 



