﻿82 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  

  

  borough 
  or 
  Grey 
  Limestone 
  ; 
  these 
  shales 
  occupy 
  a 
  wide-spread 
  area, 
  

   and 
  with 
  them 
  also 
  the 
  "Coal" 
  seam, 
  which 
  uniformly 
  occupies 
  the 
  

   area 
  from 
  the 
  coast 
  inland 
  as 
  far 
  as 
  Castleton 
  in 
  the 
  N.W., 
  and 
  Cox- 
  

   wold 
  in 
  the 
  S.W. 
  That 
  a 
  bed 
  no 
  thicker 
  than 
  this 
  should 
  yet 
  main- 
  

   tain 
  itself 
  over 
  such 
  an 
  extensive 
  district 
  points 
  to 
  a 
  remarkable 
  

   uniformity 
  of 
  condition 
  throughout 
  a 
  great 
  part 
  of 
  the 
  area 
  now 
  

   occupied 
  by 
  the 
  Yorkshire 
  Oolites 
  at 
  the 
  period 
  of 
  deposition 
  

   (Hudleston, 
  loc. 
  cit. 
  p. 
  310). 
  The 
  occurrence 
  of 
  marine 
  fossils 
  in 
  

   the 
  Middle 
  Shales 
  is 
  extremely 
  rare 
  ; 
  but 
  one 
  or 
  two 
  Monomyarian 
  

   Bivalves 
  have 
  occurred. 
  A 
  large 
  flora, 
  including 
  Equisetacece, 
  

   Lycopodiacece, 
  Filices, 
  Cycadacece, 
  and 
  Coniferce, 
  occurs 
  in 
  the 
  Lower 
  

   and 
  Middle 
  Shales 
  — 
  about 
  50 
  species 
  in 
  the 
  Middle 
  Shales 
  of 
  

   Gristhorpe, 
  10 
  at 
  Cloughton 
  Wyke, 
  and 
  30 
  in 
  the 
  Lower 
  Shales 
  

   of 
  Hayburn 
  Wyke 
  and 
  Whitby 
  &c. 
  ; 
  hence 
  the 
  persistent 
  band 
  of 
  

   coal 
  in 
  the 
  Gristhorpe 
  beds 
  or 
  Middle 
  Shale, 
  which 
  had 
  such 
  an 
  

   extensive 
  geographical 
  range. 
  This 
  band 
  of 
  coal, 
  averaging 
  about 
  

   12 
  inches 
  thick, 
  doubtless 
  is 
  due 
  to 
  the 
  growth 
  and 
  decomposition 
  of 
  

   this 
  flora 
  in 
  situ 
  along 
  the 
  shallow 
  shore 
  of 
  an 
  estuary 
  whose 
  area 
  

   can 
  be 
  defined 
  by 
  the 
  lateral 
  extent 
  of 
  the 
  present 
  plant-bearing 
  

   shales. 
  The 
  following 
  Table 
  (VI. 
  p. 
  &$) 
  gives 
  all 
  the 
  genera 
  known 
  

   in 
  the 
  shales 
  below 
  the 
  Scarborough 
  or 
  Grey 
  Limestone. 
  

  

  Above 
  the 
  Middle 
  Sandstones 
  and 
  Shales 
  is 
  the 
  Grey 
  Limestone, 
  or 
  

   Scarborough 
  Limestone, 
  or 
  the 
  second 
  marine 
  group 
  above 
  the 
  Dogger. 
  

   This, 
  again, 
  consists 
  of 
  marine 
  and 
  estuarinc 
  beds 
  having 
  special 
  

   features 
  and 
  organic 
  contents, 
  consisting 
  of 
  a 
  large 
  fauna 
  comprising 
  

   48 
  genera 
  and 
  nearly 
  80 
  species. 
  Cloughton 
  Wyke, 
  Hundale, 
  

   and 
  the 
  scars 
  south 
  of 
  Scarborough 
  exhibit 
  these 
  singular 
  beds 
  with 
  

   the 
  utmost 
  clearness, 
  and 
  richly 
  fossiliferous. 
  That 
  these 
  beds 
  

   represent 
  the 
  zone 
  of 
  Am 
  Humphresianus 
  and 
  Parkinsoni, 
  or 
  

   the 
  middle 
  and 
  upper 
  part 
  of 
  the 
  Inferior 
  Oolite 
  of 
  Gloucestershire, 
  

   there 
  is 
  little 
  doubt 
  ; 
  they 
  hold 
  a 
  fauna 
  partly 
  of 
  their 
  own, 
  of 
  a 
  

   northern 
  rather 
  than 
  southern 
  type, 
  yet 
  many 
  species 
  in 
  common 
  with 
  

   the 
  southern 
  true 
  Inferior-Oolite 
  Limestone. 
  This 
  important 
  

   marine 
  horizon 
  in 
  the 
  midst 
  of 
  the 
  estuarine 
  shales 
  and 
  sandstones, 
  

   with 
  here 
  and 
  there 
  a 
  freshwater 
  shell 
  (Anodon), 
  is 
  most 
  ably 
  

   described 
  by 
  Mr. 
  Hudleston. 
  I 
  have 
  collected 
  largely 
  from 
  both 
  

   the 
  Hundale 
  and 
  Scarborough 
  sections, 
  and 
  am 
  enabled 
  to 
  follow 
  and 
  

   verify 
  his 
  clear 
  descriptions. 
  

  

  The 
  fauna 
  of 
  the 
  Grey 
  Limestone 
  may 
  be 
  thus 
  generalized: 
  — 
  

  

  Genera. 
  Species. 
  

  

  Belemnites 
  1 
  1 
  

  

  Ammonites 
  1 
  4 
  

  

  Gasteropoda 
  9 
  14 
  

  

  Monomyaria 
  11 
  18 
  

  

  Dimyaria 
  , 
  19 
  27 
  

  

  Annelida 
  2 
  4 
  

  

  J3rachiopoda 
  1 
  1 
  

  

  Echinoidea 
  2 
  3 
  

  

  Asteriadae 
  , 
  , 
  « 
  2 
  3 
  

  

  48 
  T5 
  

  

  