TABLE OF CONTENTS. 



Page. 



Introduction 1 



Distribution of Early Paleozoic Bryozoa 3 



General Geology of Baltic Russia 4 



Cambrian strata 8 



A 1. Blue clay and associated strata 10 



A 2. Ungulite sandstone 10 



Ordovician and Early Silurian strata 11 



A 3. Dictyonema beds 11 



B 1. Glauconite sandstone 11 



B 2. Glauconite limestone 12 



B 3. Orthoceras limestone 13 



C 1. Echinospherites limestone 13 



C 2. Kuckers shale 14 



C3. Itferbeds : 15 



D 1. Jewe limestone. 15 



D2. Kegel beds 15 



D 3. Wassarlem beds 15 



E. Wesenberg limestone 16 



F. Lyckholm and Borkholm 16 



Paleontology of the Baltic area 19 



Ordovician formations of Upper Mississippi Valley 25 



Stones River group 26 



Black River group. 27 



The Bryozoan faunas of American Black River and earliest Trenton deposits. . 27 



Ordovician and Early Silurian strata of Arctic America 32 



Stratigraphic correlations 36 



The Bryozoan faunas 45 



Terminology 46 



Bibliography. 48 



Range of Baltic Ordovician and Early Silurian Bryozoa 49 



Descriptions of genera and species 54 



Ctenostomata 54 



Cyclostomata 58 



Cryptostomata 112 



Trepostomata 176 



Amalgamata 177 



Integrata 265 



Undetermined genera and species 339 



Explanation of plates 350 



Index 375 



V 



