Page:Popular Science Monthly Volume 53.djvu/39

Rh remains of an extensive mammalian fauna have been found, including animals of the tapir, horse, elephant, bison, deer, and other families. To this period also belong the giant sloths of the Megalonyx type. In the West Indies, the North American sloth (Megalonyx) and an extinct Hutia have been found in Cuba. Three species of rodents as large as the Virginia deer were obtained in Anguilla by Mr. Wager Ray, and determined by Professor Cope. The writer lately saw in Guadeloupe, in the possession of Mr. L. Guesde, the tooth of a small elephant, which had been discovered in the island. A tooth of the late Florida elephant has also been found in the Bahamas (Lucas). While these animals named are few in number, yet they show land connection between what are now the islands and the continent in the Pleistocene period. The subsidence in mid-Pleistocene days submerged not merely the continental bridge between North and South America, but caused all the lower land of the islands to be drowned, so that there was an almost complete extinction of mammalian life. Indeed, the tombs of this Pleistocene fauna are now largely beneath the sea.

Further biological testimony of the continental bridge is found among the extensive remains of mammals discovered at Port Kennedy, near Philadelphia, upon which Prof. E. D. Cope was engaged at the time of his recent death. These fossils belong to the old Pleistocene fauna, separated by submergence (the Columbia) from the more modern remains. Among these old Pleistocene species there occur South American types, most notably abundant remains of bears, that are not found among the fossils of the Western or Central States, but which appear to have migrated by way of the West Indian bridge.

Although a few of the higher animals might survive the general extinction caused by the submergence of the Antillean continent by escaping into the higher lands of the few remaining islands, yet these migrations—as, for example, from savannas to mountain forests—would tend to complete their extermination. Besides the restriction of areas, the changes from elevated temperate to low tropical climates would further bring about the destruction of many animals.

Finally, it may be said that the distribution of animal life requires the Pleistocene connection between North and South America; and consequently the biological and physical evidence, so far as known, coincides in bearing joint testimony of the late West Indian bridge.

.—The late West Indian continent is a geological feature which belongs to the period which just precedes the modern, and it was the breaking down and sinking of the bridge which