The presence of Symbos cavifrons might be supposed to point to a rather late date in the Pleistocene; but evidence has accumulated which indicates that it reaches back farther in time than we have supposed. Taking all into consideration, the writer concludes that the fossil vertebrates found at Natchez date back at least as far as the time of the Illinoian drift stage. There is nothing to prove that they are not as old as the Aftonian stage, except the apparent absence of camels, Elephas imperator, mastodons belonging to Gomphotherium, and a multiplicity of species of Equus.
Unfortunately, vertebrate fossils, especially those known to belong to definite horizons in the Pleistocene, are, aside from Natchez, rarely found; but near Orizaba, in Tippah County, a tooth of a horse has been discovered which appears to have been Equus leidyi (p. [200]). Remains of a deer (p. [234]) have been found in a railroad cutting at Aberdeen, Monroe County. Mastodons are not uncommon, as may be seen on consulting the pages where these animals in Mississippi are discussed (pp. 124 to 126).
TENNESSEE.
(Figure [23.])
There are not many States which furnish fewer Pleistocene deposits of any considerable area than does Tennessee. Lying, as it does, away from the sea, there are no marine Pleistocene beds; situated beyond the glacial area, there are no glacial-drift deposits; and almost half of the State, the eastern, being mountainous, with rivers running in narrow valleys, there has been little opportunity for accumulation of loose Pleistocene materials. The U. S. Geological Survey has published about 25 folios describing the geology of this mountainous part of Tennessee. One will search these folios, perhaps in vain, for any mention of Pleistocene deposits and for traces of these on the maps. Now and then mention is made of narrow strips of alluvium along some of the larger rivers; nevertheless there are evidences that in some of these strips there are Pleistocene deposits. From the mountainous region westward to near Mississippi River there have doubtless been, during the Pleistocene, better opportunities for deposition of alluvium along the river courses, but such deposits have been little studied. Along the great river forming the western boundary there is a band, 10 to perhaps 25 miles in width, overlain by loess. This may attain a depth along the river varying from 20 to 70 feet, but away from the river it thins out to a feather-edge (Glenn, Water Supply Paper 114, U. S. Geol. Surv.). Up to this time, however, it has furnished few, if any, Pleistocene fossils.
Notwithstanding the paucity of Pleistocene areas in the mountainous portion of Tennessee, this region has furnished a considerable number of species of Pleistocene vertebrates, and bids fair to furnish its due proportion (fig. 23). These species occur, not in water-laid or wind-laid deposits, but in caves which abound in the limestones of that region. In 1918 (Resources of Tenn., vol. VIII, pp. 85–142), Mr. Thomas L. Bailey located and described more than 100 caves of considerable size. Many had been worked to obtain saltpeter. Bones have been reported from a few of them; probably bones had been met with in others, but were not regarded as important. In these caves (and in others yet to be discovered) may hereafter be found numerous remains of animals. Other sources for such fossils are the crevices that are sometimes opened up in quarrying operations. Caves and crevices of this kind are found in the Alleghany Mountain region from northern Pennsylvania to Lookout Mountain in Tennessee, and from them there is already known an extensive Pleistocene fauna.
Beginning in the northeastern corner of the State, a brief survey will be made of the localities and fossils which concern us. At Kingsport, in Sullivan County (fig. 23, 1) the writer has learned of the finding of a mastodon tooth (p. [127]), but beyond the fact that it was owned by Mr. D. M. Lafitte, the writer has been able to learn nothing.
From Bristol, Sullivan County (fig. 23, 2), in the northeastern corner of the State, there has been sent to the U. S. National Museum a fragment of a maxilla containing two teeth of a tapir. This is referred to Tapirus haysii. No details regarding the place of discovery or of the geological conditions are known (p. [209]).
From Hawkins County, at a locality not specified (fig. 23, 3) another mastodon tooth has been reported by Dr. S. W. McCallie (Science, ser. 2, vol. XX, p. 333) (p. [127]). These announcements show at least that these animals could exist in those rough and elevated regions. From crevices in a marble quarry near Rogersville (fig. 23, 4), Hawkins County, there were sent many years ago to the U. S. National Museum a tooth of the horse Equus leidyi (p. [201]); and a canine tooth of a very large peccary, Mylohyus setiger (p. [222]). The same peccary has been secured from Cavetown, Maryland.
