TABLE OF CONTENTS. 
CHAPTER I. 
Introduction. 
A Glance at the probable Earliest Condition of the Earth. — Stratified Crystalline 
Eocks resulting from Changes of Sedimentary Deposits. — The Silurian System 
established and extended. — The Laurentian the Base of Paleozoic Rocks in 
Britain and elsewhere. — The Eozoon. — General Palaeozoic Succession . 
CHAPTEE II. 
Cambrian Rocks. 
Outlines, Structure, and Order of the Rocks next above the Laurentian. — The Rare 
Fossils of the Cambrian Rocks. — The Order of Conformable Succession upward 
to the ' Primordial,' or Lowest Silurian, Zone. — Slaty Cleavage. — Metamor- 
phosed Cambrian Rocks of Anglesea < . 
CHAPTEE III. 
Lower Silurian Rocks. 
Ascending Order of the Strata from beneath the Stiper Stones to the Llandeilo 
Flags of Shelve, in the original Typical Tract of the Silurian Region. — Similar 
Order of Strata in Wales from the Lingula-flags upwards. — The Llandeilo 
Rocks and their Fossils as exhibited in Shropshire. — The Range of the same 
Formation with its characteristic Fossils through Wales. — Distinction be- 
tween the Llandeilo and Caradoc Formations by Infraposition and by Fossils. 
— Graptolites exclusively Silurian . 
CHAPTEE IV. 
Lower Silurian Rocks {continued). 
The Caradoc Formation. — Shelly Sandstones of Caer Caradoc. — General Cha- 
racter and Order in the typical Silurian Tract of Shropshire. — Chief Organic 
Remains as distinguished from those of the Llandeilo Formation. — Great 
Masses of the Slaty Rocks of Wales, including the Bala Limestone, shown to 
be the Equivalents of the Caradoc of Shropshire. — Igneous Rocks, Cotem- 
poraneous and Eruptive, of Lower Silurian age 
