80 THE OCEAN WORLD. 
enormous deposits which raise banks, obstruct the navigation in 
gulfs and straits, and fill up ports, as may be seen in the port of 
Alexandria. In common with the corals and madrepores, the 
Foraminifera are great agents in helping to form the isles which surge 
up under our eyes from the bosom of the ocean in the warmer regions 
of the globe. Thus may these little bodies, scarcely appreciable to 
the sight, suffice by their accumulations to fill up seas, while perform- 
ing, too, a very considerable part in the great operations of Nature. 
Many beds of the terrestrial crust consist entirely of the remains 
of Foraminifera. In the most remote ages in the history of our 
planet, they must have lived in innumerable swarms in the seas of 
the period; they buried themselves in the bottums of the seas, and 
their shells, heaped up during many ages, now form hills of great 
thickness and extent. We may say, to give an example, that during 
the Carboniferous period, a single species of Fusulina has formed in 
Russia and the United States enormous beds of calcareous rock. 
Many beds of cretaceous formation are, in great part, composed of 
Foraminifera, and they exist in immense numbers in the white chalk 
which covers and forms the vast mountains ranging from Champagne 
in France nearly to the centre of England. 
But it is to the Tertiary formation that this group has contributed 
the most enormous deposits. The Nummulitic formation extends 
from the Alps to the Carpathians; is met with in Algiers and 
Morocco. In Egypt it was largely quarried for the building of the 
Pyramids. It is next met with in Asia Minor, and has been traced 
across Persia, and as far eastward as Bengal and the frontiers of 
China. The remains of these creatures are so abundant in the Paris 
chalk, that M. d’Orbigny found upwards of 58,000 in a small 
block (scarcely exceeding a cubic inch) of chalk from the quarries 
of Chantilly. This fact, according to this author, implies the 
existence of 3,000,000,000 of them in the cubic meétre (thirty-nine 
inches square and a small fraction) of rock! As the chalk from 
these quarries has served to build Paris, as well as the towns and 
villages of the neighbouring departments, it may be said that Paris, 
and other great centres of population which surround it, are built 
with the shells of these microscopic animals. 
Fig. 12 represents a drawing from Nature, by Messrs. d’Archiac 
and Haime, of a piece of nummulitic rock, from Nousse, in the 
Landes, which contains several species of Foraminifers. In the cele- 
brated quarries of St. Peter,at Maestrecht, the Cakarina calcitrapoides 
of Lamarck is found in the upper chalk (Fig. 13). In the calcareous 
formation of Chaussy, in the Seine and Oise district, and other parts 
