ven formation to
those of the formation next above and next below--Introduction
of new life-forms.

PART II.

HISTORICAL PALAEONTOLOGY.

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 _Eozooen Canadense_--Comparison of _Eozooen_
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
Wales--Lower Cambrian and Upper Cambrian--Cambrian deposits of
the continent of Europe and North American--Life of the Cambrian
period--Fucoids--Eophyton--Oldhamia--Sponges--Echinoderms--Annelides
--Crustaceans--Structure of Trilobites--Brachiopods--Pteropods,
Gasteropods, and Bivalves--Cephalopods--Literature.

CHAPTER IX.

The Lower Silurian period--The Silurian rocks generally--Limits
of Lower and Upper Silurian--General succession, subdivisions,
and characters of the Lower Silurian rocks of Wales--General
succession, subdivisions, and characters of the Lower Silurian
rocks of the North American continent--Life of the
period--Fucoids--Protozoa--Graptolites--Structure of
Graptolites--Corals--General structure of Corals--Crinoids--
Cystideans--General characters of Cystideans--Annelides--
Crustaceans--Polyzoa--Brachiopods--Bivalve and Univalve
Molluscs--Chambered Cephalopods--General characters of the
Cephalopoda--Conodonts.

CHAPTER X.

The Upper Silurian period--General succession of the Upper Silurian
deposits of Wales--Upper Silurian deposits of North America--Life
of the Upper Silurian--Plants--Protozoa--Graptolites--Corals--
Crinoids--General structure of Crinoids--Star-fishes--Annelides--
Crustaceans--Eurypterids--Polyzoa--Brachiopods--Structure of
Brachiopods--Bivalves and Univalves--Pteropods--Cephalopods--
Fishes--Silurian literature.

CHAPTER XI.

The Devonian period--Relations between the Old Red Sandstone
and the marine Devonian deposits--The Old Red Sandstone of
Scotland--The Devonian strata of Devonshire--Sequence and
subdivisions of the Devonian deposits of North America--Life
of the period--Plants--Protoz