﻿COTTESWOLD, 
  MIDEORD, 
  AND 
  YEOVIL 
  SANDS, 
  ETC. 
  473 
  

  

  as 
  a 
  division 
  of 
  the 
  Jura-formation, 
  or 
  a 
  separate 
  formation 
  in 
  the 
  

   Jurassic 
  system. 
  

  

  13. 
  That 
  the 
  Toarcian 
  can 
  be 
  conveniently 
  divided 
  into 
  Upper 
  

   and 
  Lower 
  Toarcian, 
  the 
  former 
  including 
  the 
  zones 
  from 
  the 
  Fal- 
  

   ciferum- 
  to 
  the 
  Opalinum-zone, 
  and 
  the 
  latter 
  the 
  Murehisonce- 
  and 
  

   Cortcavum-zones; 
  while 
  the 
  division 
  between 
  them 
  practically 
  cor- 
  

   responds 
  to 
  the 
  disappearance 
  of 
  the 
  genus 
  Grammoceras. 
  

  

  14. 
  That 
  the 
  term 
  " 
  Cephalopoda-bed 
  of 
  Gloucestershire 
  " 
  is 
  

   unscientific. 
  It 
  does 
  not 
  embrace 
  any 
  particular 
  zone, 
  does 
  not 
  begin 
  

   or 
  end 
  with 
  any 
  Ammonite 
  period, 
  and, 
  if 
  we 
  think 
  of 
  Sodbury, 
  is 
  

   not 
  referable 
  to 
  any 
  uniform 
  lithology. 
  

  

  Discussion. 
  

  

  The 
  President 
  said 
  that 
  the 
  paper 
  showed 
  a 
  large 
  amount 
  of 
  

   field-work 
  in 
  conjunction 
  with 
  palseontological 
  research, 
  and 
  helped 
  

   to 
  prove 
  that 
  much 
  had 
  yet 
  to 
  be 
  done 
  in 
  the 
  stratigraphy 
  of 
  England. 
  

   He 
  commented 
  on 
  the 
  interest 
  attaching 
  to 
  the 
  Jurassic 
  system, 
  

   where 
  the 
  zonal 
  divisions 
  were 
  so 
  well 
  marked. 
  Neumayr 
  had 
  

   enumerated 
  33 
  zones. 
  In 
  the 
  International 
  Geological 
  Map 
  of 
  

   Europe, 
  the 
  base 
  of 
  the 
  Opalinum-zone 
  had 
  been 
  adopted 
  as 
  the 
  

   lower 
  boundary 
  of 
  Middle 
  Jurassic. 
  He 
  doubted 
  the 
  advantage 
  of 
  

   admitting 
  intermediate 
  subdivisions 
  like 
  " 
  Toarcian," 
  and 
  would 
  

   prefer 
  a 
  conventional 
  arbitrary 
  limit. 
  

  

  Mr. 
  H. 
  B. 
  Woodward 
  commented 
  on 
  the 
  biological 
  character 
  of 
  

   the 
  paper. 
  In 
  England 
  the 
  entire 
  Jurassic 
  series 
  (locally) 
  was 
  con- 
  

   formable, 
  and 
  the 
  question 
  was 
  whether 
  our 
  divisional 
  lines 
  should 
  be 
  

   drawn 
  on 
  palseontological 
  or 
  stratigraphical 
  evidence. 
  A 
  zone 
  might 
  

   be 
  regarded 
  as 
  a 
  particular 
  assemblage 
  of 
  species 
  ; 
  but 
  when 
  traced 
  

   for 
  any 
  distance 
  these 
  zones 
  were 
  found 
  running 
  into 
  each 
  other. 
  He 
  

   instanced 
  especially 
  the 
  inosculation 
  of 
  the 
  zones 
  of 
  the 
  Lias, 
  as 
  

   showing 
  there 
  were 
  no 
  rigid 
  planes 
  of 
  division. 
  He 
  had 
  adopted 
  

   the 
  term 
  " 
  Midford 
  Sands 
  " 
  because 
  it 
  met 
  an 
  acknowledged 
  difficulty 
  ; 
  

   and 
  so 
  long 
  as 
  people 
  knew 
  what 
  it 
  meant, 
  he 
  could 
  not 
  see 
  any 
  

   valid 
  objection 
  to 
  its 
  use. 
  The 
  lower 
  portion 
  of 
  the 
  " 
  Sands 
  " 
  in 
  the 
  

   Bridport 
  Cliffs 
  was 
  inaccessible 
  ; 
  but 
  the 
  beds 
  passed 
  downwards 
  into 
  

   the 
  Upper 
  Lias, 
  while 
  the 
  upper 
  parts 
  were 
  more 
  nearly 
  allied 
  to 
  

   the 
  Inferior 
  Oolite. 
  He 
  referred 
  to 
  the 
  difficulties 
  in 
  connexion 
  

   with 
  the 
  naming 
  of 
  Ammonites, 
  and 
  concluded 
  that, 
  taking 
  the 
  

   Cephalopoda-beds 
  and 
  the 
  " 
  Cotteswold 
  Sands 
  " 
  together, 
  and 
  as 
  

   stratigraphically 
  equivalent 
  to 
  the 
  " 
  Yeovil 
  and 
  Bridport 
  Sands," 
  

   the 
  term 
  " 
  Midford 
  Sands 
  " 
  ought 
  not 
  to 
  be 
  changed. 
  

  

  Prof. 
  Blake 
  considered 
  that 
  the 
  Author 
  had 
  thoroughly 
  proved 
  

   his 
  case, 
  in 
  so 
  far 
  as 
  showing 
  that 
  the 
  different 
  " 
  Sands 
  " 
  were 
  not 
  

   on 
  the 
  same 
  horizon. 
  With 
  respect 
  to 
  the 
  " 
  Toarcien," 
  he 
  thought 
  

   the 
  suggestion 
  by 
  no 
  means 
  new. 
  As 
  regards 
  the 
  dividing-line 
  

   between 
  Lias 
  and 
  Oolite, 
  he 
  observed 
  that 
  in 
  South 
  Europe 
  lime- 
  

   stones 
  were 
  more 
  abundant 
  in 
  the 
  Jurassic 
  rocks. 
  We 
  ought 
  to 
  pay 
  

   some 
  attention 
  to 
  lithological 
  distinctions 
  as 
  indicating 
  physical 
  

   changes. 
  A 
  new 
  fauna, 
  and 
  that 
  by 
  no 
  means 
  Liassic, 
  made 
  its 
  

  

  