Ordovician.
Cambrian.

PRECAMBRIAN OR ARCHAEAN.


CHAPTER 2.

RECENT PERIOD--DANISH PEAT AND SHELL MOUNDS--SWISS LAKE-DWELLINGS.

(PLATE 1. A VILLAGE BUILT ON PILES IN A SWISS LAKE.
Restored by Dr. F. Keller, partly from Dumont D'Urville's
Sketch of similar habitations in New Guinea.)

Works of Art in Danish Peat-Mosses.
Remains of three Periods of Vegetation in the Peat.
Ages of Stone, Bronze, and Iron.
Shell-Mounds or ancient Refuse-Heaps of the Danish Islands.
Change in geographical Distribution of Marine Mollusca
since their Origin.
Embedded Remains of Mammalia of Recent Species.
Human Skulls of the same Period.
Swiss Lake-Dwellings built on Piles.
Stone and Bronze Implements found in them.
Fossil Cereals and other Plants.
Remains of Mammalia, wild and domesticated.
No extinct Species.
Chronological Computations of the Date of the Bronze and
Stone Periods in Switzerland.
Lake-Dwellings, or artificial Islands called "Crannoges,"