﻿8 
  0. 
  Holtedahl—Paleogeography 
  and 
  

  

  Fig. 
  5. 
  

  

  p 
  1G> 
  5. 
  — 
  Early 
  Silurian, 
  Llandovery 
  time. 
  

  

  Fig. 
  6. 
  

  

  FlGt 
  e. 
  — 
  Middle 
  Silurian, 
  Wenlock 
  time. 
  

  

  