OF SOUTH CAROLINA. 51 
seventeen percent. ‘These beds he designated as “ Miocene ”—“less recent,” from the small number 
of recent species found in this formation. Of 1021 species examined, only 176 are living. 
The next division consisted of those beds in which the recent species were present in great 
number, compared with the Miocene formation, and was therefore named “ Pliocene ”—“ more 
recent.” This formation was again sub-divided into older and newer Pliocene. 
In the newer Pliocene, out of 226 fossils, 216 were found to be of living species, and in the older 
Pliocene, of 569 species, 238 were found to be of recent species. In general the proportion is found 
to be about one half. 
Mr. Lyell estimates the number of species common to the Miocene and Pliocene at 196, of which 
114 are living, and 82 are extinct. 
In this country the terms upper, middle, and lower Tertiary, by which these divisions were 
formerly known, have given place to Mr. Lyell’s nomenclature, and although many objections have 
been made to it, nevertheless it is found quite convenient. The objections that I have heard amount 
to this, that with the progress of discovery the “per centage” must alter; but it must be recollected 
that the distinguished author never intended to limit it strictly to that found’ among the fossils 
first examined. Had he done so our Eocene would necessarily be referred to some other formation, 
for it contains not a single recent species. 
The divisions of the Tertiary in general use with American Geologists are Eocene, Miocene, 
Pliocene, and Post Pliocene. 
Eocene Formation—The principal foreign localities of this formation are the London and Paris 
basins, and numerous others in various parts of France and Italy. 
The Paris basin is deservedly the most noted, as the grand depository of the materials from 
which Cuvier restored so many strange Pachydermata. 
The remains of fishes are numerous, particularly those of the family of Sharks, Ray and Sword 
fish. Turtles and other reptilia are not uncommon, and some remains of birds have been found. 
Among the Mammalian remains are those of Cetacea, the Monkey and Opossum. 
Of mollusca, Gasteropods, and, with the exception of the Nautilus, the Cephalopoda, have disap- 
peared. 
In the United States this formation may be traced from Maryland to the Mississippi. The char- 
acteristic and most common fossils are Ostrea Selleeformis, Cardita Planicosta, and Turritella 
Mortoni. | 
Miocene Formation.—The beds composing this formation are generally made up of loose mate- 
rials, such as sand, clay, gravel and marl, rarely indurated. It is seldom thick or continuous, being 
for the most part found in detached patches of limited extent. In the United States the thickest 
beds do not exceed 80 feet. 
The formation designated in England as the “Crag,” is Miocene. On the continent of Europe 
this formation is widely distributed. 
In this country it is found extending along the coast of the Atlantic, from New ‘Jersey to the 
Savannah, beyond which point, towards the South, it has not yet been recognized. 
In genera the fossils differ but little from those of the preceding formation. 
Post Pliocene—In mineral composition the beds of this formation differ but little from those of 
the Miocene, excepting that they contain less lime. The fossils, with a few exceptions, are 
