The biological relations of fossils--Extinction of
life-forms--Geological range of different species--Persistent types
of life--Modern origin of existing animals and plants--Reference
of fossil forms to the existing primary divisions of the animal
kingdom--Departure of the older types of life from those now in
existence--Resemblance of the fossils of a given formation to
those of the formation next above and next below--Introduction
of new life-forms.


PART II.

HISTORICAL PALÆONTOLOGY.


CHAPTER VII.

The Laurentian and Huronian periods--General nature, divisions,
and geographical distribution of the Laurentian deposits--Lower
and Upper Laurentian--Reasons for believing that the Laurentian
rocks are not azoic based upon their containing limestones, beds of
oxide of iron, and graphite--The characters, chemical composition,
and minute structure of _Eozoön Canadense_--Comparison of _Eozoön_
with existing Foraminifera--_Archoeosphoerinoe_--Huronian
formation--Nature and distribution of Huronian deposits--Organic
remains of the Huronian--Literature.

CHAPTER VIII.

The Cambrian period--General succession of Cambrian deposits in