This document was produced 
by scanning the original publication. 
Ce document est le produit d'une 
numerisation par balayage 
de la publication originale. 
! 
CONTENTS. 
Page 
Introduction 1 
Subdivisions of the Trenton group 1 
Cystoidea 2 
Brachiopoda 14 
Gastropoda 28 
Trilobita 29 
Index 63 
i 
Illustrations. 
Plates I-XI 41-61 
