No. 3. — Expedition to the Baltic Provinces of Russia and Scandinavia, 



1914. 



Part 1 . — The Correlation of the Ordovician Strata of the Baltic 

 Basin with those of Eastern North America. 



By Percy E. R.\ymond. 

 TABIDS OF CONTENTS. 



Page. 



Preface 179 



The Ordovician strata in the Governments of Petrograd and Esthonia, 



Russia ............. 181 



The Lower and Middle Ordovician of Sweden 206 



Correlation of the American with European formations . . . 226 



Correlation of the Trenton in America 251 



General discussion of Russian early Ordovician faunas . . . 263 



Detailed sections in Russia 272 



Bibliography ........... 280 



Explanation of Plates 



PREFACE. 



The writer has been engaged since the summer of 1900, in the study 

 of the stratigraphy and faunas of the Middle Ordovician formations 

 of the northeastern United States and Canada. During all that time 

 the need of a personal knowledge of the Ordovician strata of northern 

 Europe had become more pressing, so that he was exceedingly glad of 

 a grant from the Shaler Memorial fund which enabled him to spend 

 several months of the summer of 1914 in Russia and Scandinavia. 

 With the cooperation of Dr. W. H. Twenhofel, who studied especially 

 the Upper Ordovician and Silurian strata, a rather complete, though 

 necessarily hasty survey of the Lower Palaeozoic strata of the districts 

 mentioned was completed between May 1 and September 30 of 1914, 

 and large collections secured. The outbreak of the war interfered 

 with the completion of the work as planned, and quite seriously 

 affects the present report, since all the collections of three men during 

 a month spent in Esthonia were in Russia at the time of the outbreak 

 of hostilities and it is somewhat doubtful if they ever reach this 

 country. Our conclusions on some points are therefore of a tentative 

 nature, and if we should be so fortunate as to receive the collections, 

 a supplementary report may be necessary. 



