﻿COTTESWOLD, 
  MIDFORD, 
  AND 
  YEOVIL 
  SANDS, 
  ETC. 
  455 
  

  

  to 
  fifteen 
  feet 
  ; 
  and 
  it 
  may 
  be 
  divided 
  into 
  four 
  stages. 
  The 
  lowest 
  

   stage 
  — 
  the 
  Striatulum-be&s 
  — 
  contains 
  Gramm. 
  striatulum, 
  Gramm. 
  

   Bhigmanni, 
  Pseudolioceras 
  compactile, 
  Haugia 
  Eseri, 
  Haugia 
  illustris, 
  

   &c. 
  The 
  stage 
  above 
  this 
  — 
  the 
  Dispcmsum-beds 
  — 
  contains 
  

   Gramm. 
  dispansum 
  abundantly 
  in 
  some 
  places, 
  in 
  others 
  Gramm. 
  

   fallaciosum 
  takes 
  its 
  place 
  ; 
  here 
  belong 
  also 
  Gramm. 
  Scemanni 
  

   (Dumortier), 
  Gramm. 
  doerntense, 
  Hammatoceras 
  insigne, 
  Oxynoticeras 
  

   discoides. 
  

  

  The 
  third 
  stage 
  — 
  the 
  Dumortieria-loeds 
  — 
  obtains 
  its 
  name 
  from 
  the 
  

   presence 
  of 
  several 
  species 
  of 
  the 
  extraordinary 
  genus 
  Dumortieria, 
  

   of 
  which 
  Dumortieria 
  rhodanica 
  is 
  the 
  most 
  abundant. 
  Here 
  also 
  

   come 
  Dum. 
  Levesquei, 
  Bum. 
  striatulo-costata, 
  Haug, 
  Oatulloceras 
  

   Dumortieri, 
  Pelecoceras 
  affine, 
  Pelecoceras 
  serrodens, 
  Terebratula 
  hares- 
  

   JieldensiSf 
  Rliynch. 
  cynocephala, 
  &c. 
  

  

  The 
  fourth 
  stage 
  — 
  the 
  Moorei-beds 
  — 
  completes 
  the 
  series 
  known 
  

   as 
  the 
  Cephalopoda-bed. 
  It 
  is 
  characterized 
  by 
  some 
  peculiar 
  species, 
  

   namely, 
  Dumortieria 
  Moorei, 
  Gramm. 
  aalense, 
  Gramm. 
  Steinmanni, 
  

   Gramm. 
  fluitans, 
  Gramm. 
  subcomptum, 
  and 
  occasionally 
  Lioceras 
  

   opalinum. 
  In 
  addition 
  Hamm. 
  Alleoni, 
  Lytoceras 
  Wrighti, 
  Du- 
  

   mortieria 
  subundulata 
  , 
  Gramm. 
  mactra, 
  Terebratula 
  haresjieldensis 
  

   and 
  Rhynchonella 
  cynocephala 
  are 
  found. 
  

  

  We 
  have 
  now 
  reached 
  the 
  top 
  of 
  the 
  so-called 
  Cephalopoda-bed, 
  

   and 
  we 
  pass 
  into 
  what 
  was 
  called 
  by 
  Mr. 
  Witchell 
  the 
  "sandy 
  

   ferruginous 
  limestone 
  " 
  *. 
  The 
  lowest 
  bed 
  of 
  this 
  series 
  is 
  harder 
  

   and 
  darker 
  than 
  the 
  others, 
  and 
  contains 
  Lioc. 
  opalinum 
  in 
  fine 
  pro- 
  

   portions, 
  also 
  Pseudolioc. 
  Beyrichi, 
  Ludwigia 
  sp., 
  &c. 
  The 
  rest 
  of 
  

   the 
  series 
  up 
  to 
  the 
  white, 
  oolitic 
  " 
  Lower 
  Limestone 
  " 
  may 
  be 
  described 
  

   as 
  generally 
  light-yellow, 
  sandy, 
  sometimes 
  hardly 
  oolitic 
  stone, 
  

   containing 
  Lioc. 
  opalinum, 
  Lioceras 
  ambiguum 
  ?, 
  Hammatoceras 
  sp., 
  

   and 
  Parkinsonia 
  scissa. 
  The 
  whole 
  of 
  the 
  " 
  sandy 
  ferruginous 
  

   limestones 
  " 
  may 
  be 
  classed 
  as 
  another 
  stage 
  — 
  the 
  Opalinum-be&s. 
  

   They 
  probably 
  form 
  the 
  uppermost 
  portion 
  of 
  the 
  Opalinum-zone, 
  

   and 
  are 
  evidently 
  on 
  exactly 
  the 
  same 
  horizon 
  as 
  the 
  bed 
  of 
  the 
  

   Burton-Bradstock 
  section. 
  

  

  Now, 
  if 
  we 
  look 
  at 
  this 
  whole 
  series 
  of 
  beds 
  and 
  the 
  fauna 
  which 
  

   they 
  contain, 
  we 
  shall 
  be 
  at 
  once 
  struck 
  with 
  the 
  difference, 
  not 
  

   only 
  of 
  species 
  but 
  of 
  genera, 
  which, 
  each 
  stage 
  exhibits 
  from 
  the 
  

   one 
  below 
  or 
  above 
  it 
  ; 
  and 
  I 
  can 
  confidently 
  say 
  that, 
  during 
  the 
  

   whole 
  course 
  of 
  my 
  collecting 
  from 
  these 
  strata, 
  I 
  have 
  invariably 
  

   found 
  that 
  this 
  order 
  is 
  most 
  exactly, 
  and 
  even 
  extraordinarily, 
  

   maintained. 
  

  

  No 
  one 
  has 
  yet, 
  I 
  believe, 
  attempted 
  to 
  analyze 
  and 
  divide 
  the 
  

   Gloucestershire 
  Cephalopoda-bed 
  in 
  this 
  minute 
  fashion. 
  Two 
  

   divisions 
  at 
  the 
  most 
  were 
  made 
  ; 
  but 
  for 
  our 
  present 
  purpose 
  many 
  

   divisions 
  are 
  necessary 
  ; 
  and 
  any 
  one, 
  when 
  he 
  becomes 
  thoroughly 
  

   acquainted 
  with 
  the 
  different 
  beds 
  and 
  their 
  Ammonite-fauna, 
  will 
  

   be 
  able 
  to 
  see 
  that 
  these 
  divisions 
  are 
  fairly 
  well 
  characterized. 
  It 
  

   is, 
  in 
  fact, 
  only 
  by 
  making 
  such 
  particular 
  divisions 
  that 
  we 
  are 
  able 
  

  

  * 
  "Basement-beds 
  of 
  the 
  Inferior 
  Oolites 
  of 
  Gloucestershire," 
  Quart. 
  Journ. 
  

   Geol. 
  Soc. 
  vol. 
  xlii. 
  p. 
  264 
  et 
  seg. 
  

  

  