﻿320 
  J. 
  E. 
  MA.EE 
  ON 
  THE 
  CAMBRIAN 
  AND 
  

  

  § 
  3. 
  Comparison 
  of 
  the 
  Strata 
  with 
  British 
  and 
  Bohemian 
  Deposits. 
  

  

  The 
  Scandinavian 
  strata 
  have 
  been 
  correlated 
  with 
  those 
  of 
  Britain 
  

   and 
  Bohemia 
  by 
  various 
  authors, 
  notably 
  by 
  Dr. 
  Linnarsson 
  (cf. 
  

   Geol. 
  Mag. 
  1876, 
  p. 
  245, 
  and 
  1878, 
  p. 
  278 
  ; 
  Ofv. 
  af 
  K. 
  Yet.-Akad. 
  

   Forh. 
  1873, 
  no. 
  5 
  ; 
  and 
  Lap 
  worth, 
  Geol. 
  Mag. 
  1880, 
  p. 
  29), 
  by 
  Dr. 
  

   Tornqvist 
  (Ofv. 
  af 
  K. 
  Yet.-Akad. 
  Forh. 
  1879, 
  no. 
  2, 
  p. 
  63), 
  by 
  Prof. 
  

   Lapworth 
  (Ann. 
  and 
  Mag. 
  Nat. 
  Hist. 
  ser. 
  5, 
  vol. 
  iii.), 
  and 
  by 
  Dr. 
  Tull- 
  

   berg 
  (Geol.Fciren. 
  i 
  Stockh.Forh. 
  1880, 
  no. 
  59, 
  Bd. 
  v. 
  no. 
  3). 
  I 
  would 
  

   here 
  consider 
  more 
  fully 
  the 
  beds 
  at 
  the 
  top 
  of 
  the 
  Cambrian 
  and 
  

   the 
  base 
  of 
  the 
  Silurian 
  systems. 
  Passing 
  over 
  the 
  representatives 
  

   of 
  the 
  Harlech, 
  Menevian, 
  and 
  Lingula 
  -formations, 
  and 
  commencing 
  

   with 
  the 
  Ceratopyge-limestone, 
  we 
  find 
  this 
  correlated 
  by 
  Dr. 
  

   Linnarsson 
  with 
  the 
  Tremadoc 
  slates 
  of 
  England 
  (Kongl. 
  Yet.-Akad. 
  

   Forh. 
  1869). 
  The 
  Orthoceras-limestone 
  is 
  underlain 
  by 
  shales 
  

   with 
  Phylloc/raptus 
  in 
  "Westrogothia, 
  and 
  overlain 
  by 
  Phyllograptus- 
  

   shales 
  in 
  Scania, 
  as 
  described 
  by 
  Dr. 
  Linnarsson, 
  whilst 
  the 
  genus 
  is 
  

   found 
  in 
  shales 
  intercalated 
  with 
  the 
  Orthoceras-limestone 
  of 
  Dale- 
  

   carlia 
  (Tornqvist, 
  Geol. 
  Foren. 
  i 
  Stockk. 
  Forh. 
  1879, 
  no. 
  56, 
  

   Bd. 
  iv. 
  no. 
  14, 
  p. 
  446); 
  so 
  that 
  Tornqvist 
  (Ofv. 
  af 
  K. 
  Yet.-Akad. 
  

   Forh. 
  1879, 
  no 
  2, 
  p. 
  69) 
  correlates 
  this 
  limestone 
  with 
  the 
  Arenig 
  

   group 
  of 
  Britain. 
  The 
  limestone 
  itself 
  seems 
  to 
  have 
  been 
  a 
  shallow- 
  

   water 
  deposit; 
  and 
  its 
  fauna 
  is 
  interesting 
  as 
  bearing 
  on 
  the 
  subject 
  

   of 
  migrations. 
  The 
  deep-water 
  fauna, 
  as 
  seen 
  in 
  the 
  thin 
  band 
  of 
  

   red 
  shales 
  at 
  Skattungbyn 
  in 
  Dalecarlia, 
  and 
  in 
  the 
  Phyllograptus- 
  

   shales, 
  corresponds 
  with 
  that 
  of 
  D. 
  d. 
  1 
  y 
  of 
  Bohemia, 
  and 
  of 
  the 
  Arenig 
  

   of 
  Britain. 
  

  

  The 
  succeeding 
  Graptolitic 
  shales 
  of 
  Scania 
  have 
  been 
  correlated 
  

   by 
  Prof. 
  Lapworth 
  and 
  Dr. 
  Tullberg 
  (Joe. 
  cit.), 
  zone 
  for 
  zone, 
  with 
  

   the 
  corresponding 
  beds 
  of 
  the 
  south 
  of 
  Scotland 
  ; 
  but 
  these 
  Grapto- 
  

   litic 
  shales 
  are 
  replaced 
  by 
  shallower-water 
  deposits 
  in 
  "Westrogothia, 
  

   Dalecarlia, 
  and 
  the 
  neighbourhood 
  of 
  Christiania. 
  

  

  In 
  Dalecarlia, 
  as 
  in 
  Bohemia, 
  above 
  the 
  Arenig 
  beds 
  are 
  two 
  

   series 
  of 
  shallow-water 
  deposits, 
  and 
  two 
  of 
  deeper 
  water. 
  The 
  

   Cystidean 
  limestone 
  of 
  Dalecarlia, 
  containing 
  Cystideans 
  of 
  the 
  

   aurantium-tyjie, 
  along 
  with 
  Ohasmojos, 
  Stygina, 
  &c, 
  is 
  supposed 
  bj 
  r 
  

   Tornqvist 
  to 
  be 
  the 
  equivalent 
  of 
  the 
  Lower 
  Bala 
  of 
  Britain 
  ; 
  and 
  it 
  

   corresponds 
  in 
  position 
  with 
  D. 
  2 
  of 
  Bohemia, 
  although 
  there 
  is 
  no 
  

   resemblance, 
  either 
  lithological 
  or 
  palaeontological, 
  between 
  the 
  two 
  

   deposits. 
  The 
  next 
  succeeding 
  formation, 
  however, 
  the 
  green 
  shales 
  

   of 
  Kargarde 
  and 
  Fjecka 
  do 
  somewhat 
  resemble 
  the 
  shales 
  D. 
  3 
  of 
  

   Bohemia 
  ; 
  they 
  seem 
  to 
  be 
  more 
  allied 
  to 
  the 
  Cystidean 
  limestone 
  

   than 
  to 
  the 
  Trinucleus- 
  shales, 
  and 
  probably 
  are 
  also 
  of 
  Lower 
  Bala 
  

   age. 
  The 
  hard 
  limestone 
  of 
  Fjecka 
  lying 
  below 
  the 
  Trinucleus- 
  

   shales 
  may 
  be 
  the 
  same 
  as 
  the 
  band 
  D. 
  4 
  of 
  Bohemia, 
  as 
  the 
  

   succeeding 
  Trinucleus-shales, 
  which 
  are 
  similar 
  in 
  character 
  in 
  various 
  

   parts 
  of 
  Sweden, 
  have 
  long 
  since 
  been 
  correlated 
  by 
  Dr. 
  Linnarsson 
  

   with 
  band 
  D. 
  5 
  of 
  Bohemia 
  ; 
  I 
  should, 
  however, 
  correlate 
  them 
  

   only 
  with 
  the 
  lower 
  part 
  of 
  that 
  band, 
  viz. 
  the 
  Kraluv 
  Dvur 
  shales. 
  

   Not 
  only 
  are 
  the 
  Trilobites 
  identical 
  in 
  genera, 
  but 
  the 
  species 
  arc 
  

  

  