CONTENTS. xi 
CHAPTERAIZG 
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 succes- 
sion, subdivisions, and characters of the Lower Silurian rocks 
of the North American continent—Life of the period—Fucoids— 
Protozoa—Graptolites—Structure of Graptolites—Corals—Gene- 
ral 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, . - 90-114 
CHAP TT Ks xX. 
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, ; . ei) LE5-132 
CHAP TER) 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— Protozoa—Corals—Crinoids—Pentremites— 
Annelides— Crustaceans — Insects— Polyzoa— Brachiopods—Bi- 
valves — Univalves—Pteropods—Cephalopods— Fishes—General 
divisions of the Fishes—Palzeontological evidence as to the inde- 
pendent existence of the Devonian system as a distinct formation 
—Literature, ; 5 : : ‘ , : F . 132-157 
CHAP TER: oir. 
The Carboniferous period—Relations of Carboniferous rocks to De- 
vonian — The Carboniferous Limestone or Sub - Carboniferous 
series—The Millstone-grit and the Coal-measures—Life of the 
period—Structure and mode of formation of Coal—Plants of the 
Coal, ; : ; ‘ , : ‘ : : a Sy -170 
CHAPTER: XE. 
Animal life of the Carboniferous period—Protozoa—Corals—Crinoids 
—Pentremites—Structure of Pentremites—Echinoids— Structure 
of Echinoidea — Annelides — Crustacea — Insects—Arachnids— 
Myriapods— Polyzoa—Brachiopods—Bivalves and Univalves— 
Cephalopods — Fishes — eee ne cae —.Litera- 
ture, : iy in Pict BRO ESR 
