Bulletin of the Museum of Comparative Zodlogy 
AT HARVARD COLLEGE. 
Vout. LVI. No. 4. 
GEOLOGICAL SERIES, Vol. X. SHALER MEMORIAL SERIES, No. 3. 
EXPEDITION TO THE BALTIC PROVINCES OF RUSSIA 
AND SCANDINAVIA, 1914. 
PART 2.— THE SILURIAN AND HIGH ORDOVICIAN STRATA OF 
ESTHONIA, RUSSIA AND THEIR FAUNAS. 
PART 3—AN INTERPRETATION OF THE SILURIAN SECTION 
OF GOTLAND. 
By W. H. TWENHOFEL. 
Wits Five Puartes. 
CAMBRIDGE, MASS., U.S. A.: 
PRINTED FOR THE MUSEUM. 
Juty, 1916. 
