104 POST-PLEIOCENE FOSSILS. 



Figures 17, 18, represent two specimens of upper last molars, above mentioned, from 

 one of the Natchez islands. They are hard, blackened, and water-rolled, and neither 

 differ in size nor complexity from their homologues of the domestic Horse. 



Figure 23, Plate XVI, represents a remarkably well preserved specimen of a lower 

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

 ciation 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 large 

 molar, labelled from Texas, represented in figure 10, Plate XV. The tooth is of the 

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

 its enamel ; in both of which characters it differs in such a remarkable degree from the 

 corresponding tooth, represented in figure 8, from the Post-Pleiocene formation of South- 

 Carolina, that it appears hardly possible that these two teeth should belong to the same 

 species of Horse. 



Specimens of upper and lower molars, and incisors, have been submitted to my inspec- 

 tion, by Prof. E. Emmons, who informed me they were obtained from North-Carolina. 

 One of the specimens, a remarkably well preserved superior molar tooth, is represented 

 in figures 16, Plate XV, and 28, of Plate XVI. 



Figure 9, Plate XV, also represents a well-preserved superior molar tooth, being the 

 first of the right side. It was sent to me for examination by Dr. B. F. Shumard, who 

 obtained it from the Illinois bluffs, (the quartenary formation, or the bluff formation of 

 Missouri, of the Geological Report,) six miles west of St. Louis. 



The Cabinet of the Academy of Natural Sciences, of Philadelphia, also contains the 

 following remains of the extinct Horse : 



A tibia, from the ravines of Natchez, Mississippi, obtained by Dr. Dickeson, together 

 with the remains of other extinct animals, previously mentioned. The bone is sixteen 

 inches long, five and a quarter inches broad at the proximal extremity, and three and 

 three-quarter inches broad at the distal extremity. 



A metacarpal bone, a calcaneum, a metatarsal bone, two first phalanges and a third 

 phalanx, and an axis, which together with remains of Ekphas and Mastodon, from 

 Big-bone-lick, Kentucky, were presented to the American Philosophical Society, by 

 Thomas Jefferson, President of the United States. 



The metacarpal bone is ten inches long, and four and a quarter inches in circumference 

 at the middle of its shaft ; the tuberosity of the calcaneum is two and a half inches in 

 depth ; the metatarsal bone is one foot long, and about five inches in circumference at its 

 middle ; the first phalanx is three and three-quarter inches long, and two and a half 

 inches broad at the proximal extremity ; the last phalanx measures two and three-quarter 

 inches on its anterior slope, and four inches broad; and the axis is six and a half inches long. 



Lastly, the same collection contains a second phalanx, two inches long and two and a 

 quarter inches broad, from Benton county, Missouri, where it was found in association 

 with large quantities of the remains of Ekphas, Mastodon, and Bootherium cavifrons. 



