MISSISSIPPI.
(Map [17].)
1. Orizaba, Tippah County.—In the U. S. National Museum (No. 1907) is a fossil tooth of a horse, a third or fourth right premolar, found apparently not far from this little town. It is labeled as having been picked up at Lander’s mill, 9 miles south of Ripley, on Cane Creek, out of débris of Cretaceous marl, and given to Dr. T. E. Stanton. How it came to be mingled with the marl is not known. The tooth is only moderately worn, the height being 75 mm. The length of the grinding-surface is 28 mm., the width 27 mm. It has the enamel unusually strongly folded. The tooth is referred provisionally to Equus leidyi.
2. Natchez, Adams County.—Elsewhere will be found an account of the discovery of fossil vertebrates near Natchez by Dr. M. W. Dickerson (p. 390), among which were found horse-teeth, referred to two species. One of these horses, represented, as supposed, by 12 teeth, was at first called by Leidy Equus americanus (Proc. Acad. Nat. Sci. Phila., 1847, vol. III, p. 265, plate II); but later Equus complicatus (Proc. cit., 1858, p. 11). In 1901 (Bull. Amer. Mus. Nat. Hist., vol. XIV, p. 109, fig. 7), Gidley selected one of the teeth, that of Leidy’s plate II, figs. 1, 6, referred to above, as the special type of the species Equus complicatus. These Natchez teeth are now in the collection of the Philadelphia Academy of Natural Sciences.
Some of the teeth from Natchez were described by Leidy in 1860 (Holmes’s Post-Pliocene Fossils of South Carolina, pp. 100–105, plate XV, figs. 11–15, plate XVI, figs. 24–26, 30, 31) as Equus complicatus. Others (pp. 100105, plate XV, figs. 17, 18, plate XVI, fig. 27) were referred to a hitherto unrecognized species Equus fraternus.