Bulletin of the Museum of Comparative Zoology 



AT HARVARD COLLEGE. 



Vol. LVI. No. 4. 



OEOLOOICAL SERIES. Vol. X. SHALER MEMORIAL SERIES, No. 3. 



1 



EXPEDITION TO THE BALTIC PROVINCES OF RUSSIA 

 AND SCANDINAVIA, 1914. 



FXRT 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. 



With Five Plates. 



CAMBRIDGE, M.lSS., U. S. A.: 



PRINTED FOR THE MUSEUM, 



July, 1916. 



