To the writer it seems improbable that the commingling of Procamelus and the rhinoceroses with Pleistocene forms should occur thus accidentally so often and at such widely removed localities. It appears more probable that these Tertiary genera did not become extinct so early as has been supposed and that the association was not a secondary one. The association is what might be expected in collections made in deposits of the earliest Pleistocene.
It must not be forgotten in these discussions that the Pleistocene genera and species with which the collections in question are being compared are those of the so-called Equus beds, which appear to represent the fauna of the first interglacial stage. This, however, was preceded by the Nebraskan, the first glacial, which probably occupied a long period of time; possibly it was half as long as all the rest of the Pleistocene (Chamberlin and Salisbury, Geology, vol. III, p. 383). About the vertebrate life of this long stage we know as yet very little. The writer is quite convinced that the Idaho formation and the Alachua, or Bone Valley, belong to the earliest Pleistocene.
Marion County.—In a fissure in the limestone-rock quarry at Ocala there has been found an important collection of vertebrates. The following list is thought to include all that have been reported:
- Trucifelis floridana.
- Sylvilagus sp. indet.
- Elephas columbi (p. [158]).
- Bison sp. indet.
- Odocoileus sp. indet. (p. [233]).
- Procamelus minimus (p. [224]).
- Tapirus sp. indet. (p. [207]).
- Equus leidyi (p. [196]).
- Dasypus sp. indet. (p. [38]).
- Terrapene formosa.
- Testudo distans.
- T. incisa.
- T. ocalana.
A part of this list was published by Sellards in 1916 (8th Ann. Rep. Florida Geol. Surv., p. 103). The tortoises were described in the same volume.
Inasmuch as Trucifelis floridana has been found in the Pleistocene at Vero, Florida, one may safely regard the specimen found at Ocala as also of Pleistocene age. All of the other mammals are admitted to be of Pleistocene age except Procamelus minimus. The fissure may have been open during some part of the Nebraskan stage.
Volusia County.—At Daytona, situated on the east coast, therefore on the youngest terrace, remains of Mammut americanum (p. [122]) have been found. At DeLand there has been recovered the skull of a dolphin which Sellards (8th Ann. Rep. Florida Geol. Surv., p. 107, plate XIV) has described as Globicephalus bœreckii (p. [20]). It was found at a depth of 10 feet, in sands which overlie Pliocene shell marls. The sands are regarded as belonging probably to the Pleistocene. DeLand is on the Tsala Apopka terrace. At a depth of 10 feet there was reached the supposed marine base of this terrace.
Orange County.—As stated on page [196], a tooth of an extinct horse was found somewhere in the county.
Pinellas County.—On the western shore of Tampa Bay (p. [159]), near St. Petersburg, at Indian Rock, a tooth of Elephas columbi was found.
Hillsboro and Manatee Counties.—The region around Tampa Bay is important because of the wealth of vertebrate fossils dredged up by the collectors of phosphate rock from the beds of Hillsboro, Alafia, and Manatee Rivers. Unfortunately, few accurate records have been kept of localities and conditions of occurrence of the fossils, and we usually know only that a collection was made in a certain river, perhaps not so much as that. For that reason it is concluded to group together all the fossils regarded as Pleistocene and known to have been found in Hillsboro, Manatee, and Sarasota Counties. In order to indicate as far as possible the localities, the names of the species are followed by contractions which apply as follows.