﻿348 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  [Apr. 
  27, 
  

  

  have 
  already 
  noticed 
  as 
  having 
  yielded 
  most 
  of 
  the 
  Fish-remains 
  ; 
  on 
  

   this 
  account 
  I 
  propose 
  to 
  call 
  it 
  the 
  Fulwell 
  Fish-bed. 
  About 
  eight 
  

   feet 
  of 
  limestone 
  underlie 
  the 
  Fish-bed, 
  the 
  uppermost 
  being 
  con- 
  

   cretionary 
  and 
  laminated, 
  and 
  the 
  lower 
  laminated 
  and 
  argillaceous 
  ; 
  

   the 
  most 
  inferior 
  stratum 
  passing 
  into 
  a 
  bed 
  of 
  yellow-brown 
  and 
  

   white 
  laminated 
  marl 
  and 
  clay, 
  one 
  foot 
  thick. 
  The 
  laminated 
  marl 
  

   rests 
  upon 
  the 
  Middle 
  Limestone, 
  which 
  at 
  Fulwell 
  assumes 
  its 
  

   pseudobrecciated 
  phase, 
  being 
  light-coloured, 
  friable 
  with 
  hard 
  con- 
  

   cretions, 
  unstratified, 
  and 
  unfossiliferons. 
  

  

  The 
  accompanying 
  section 
  (fig. 
  1) 
  of 
  the 
  Fulwell 
  limestone 
  will, 
  

   perhaps, 
  render 
  this 
  account 
  easier 
  of 
  comprehension 
  ; 
  and 
  the 
  

   sequence 
  of 
  strata 
  indicated 
  may 
  be 
  seen, 
  either 
  wholly 
  or 
  in 
  part, 
  

   in 
  the 
  various 
  quarries 
  at 
  Fulwell 
  Hill, 
  but 
  more 
  particularly 
  in 
  the 
  

   old 
  quarry 
  of 
  Sir 
  H. 
  Williamson. 
  The 
  basal 
  beds 
  of 
  the 
  Upper 
  

   Limestone, 
  and 
  their 
  junction 
  with 
  the 
  Middle 
  Limestone, 
  are 
  well 
  

   exposed 
  in 
  the 
  cutting 
  on 
  the 
  North-Eastern 
  Railway, 
  at 
  Fulwell. 
  

  

  The 
  limestone 
  of 
  the 
  Fish-bed 
  in 
  the 
  new 
  quarry, 
  Fulwell, 
  though 
  

   difficult 
  to 
  describe 
  in 
  precise 
  terms, 
  on 
  account 
  of 
  its 
  liability 
  to 
  

   structural 
  changes, 
  is 
  almost 
  invariably 
  laminated 
  or 
  slaty, 
  the 
  

   laminae 
  usually 
  showing 
  repeated 
  alternations 
  of 
  crystalline, 
  earthy, 
  

   and 
  compact 
  textures. 
  The 
  crystalline 
  laminae 
  are 
  generally 
  grey 
  

   or 
  brown 
  in 
  colour, 
  and 
  the 
  earthy 
  and 
  compact 
  laminae 
  of 
  various 
  

   shades 
  of 
  yellow. 
  A 
  band 
  of 
  soft 
  and 
  rather 
  friable 
  light-yellow 
  

   limestone 
  runs 
  through 
  the 
  centre 
  of 
  the 
  bed. 
  In 
  some 
  places 
  the 
  

   limestone 
  of 
  this 
  bed 
  becomes 
  generally 
  more 
  highly 
  crystalline 
  and 
  

   somewhat 
  concretionary 
  in 
  character; 
  when 
  this 
  occurs, 
  the 
  plane 
  

   surfaces 
  are 
  rough 
  and 
  more 
  or 
  less 
  irregular. 
  Otherwise 
  the 
  sur- 
  

   faces 
  of 
  the 
  laminae 
  are 
  usually 
  smooth, 
  forming 
  a 
  fine 
  matrix 
  for 
  

   the 
  fossils 
  they 
  enclose. 
  

  

  In 
  the 
  old 
  quarry 
  the 
  bed 
  decreases 
  somewhat 
  in 
  thickness, 
  is 
  

   not 
  so 
  regularly 
  laminated, 
  and 
  is 
  softer 
  and 
  more 
  earthy 
  than 
  in 
  

   the 
  new 
  quarry. 
  

  

  At 
  Marsden, 
  the 
  limestone 
  which 
  has 
  yielded 
  me 
  Fish-remains 
  is 
  

   soft, 
  yellow, 
  and 
  finely 
  laminated, 
  being, 
  in 
  fact, 
  the 
  well-known 
  

   " 
  flexible 
  limestone 
  " 
  of 
  geologists. 
  

  

  In 
  the 
  Fish-bed 
  of 
  the 
  new 
  quarry, 
  and 
  wherever 
  else 
  these 
  

   fossils 
  occur, 
  the 
  specimens 
  almost 
  invariably 
  appear 
  to 
  have 
  be- 
  

   longed 
  to 
  perfect 
  individuals, 
  or, 
  at 
  least, 
  the 
  dermoskeleton, 
  fins, 
  

   and 
  bones 
  of 
  the 
  head 
  seem 
  to 
  have 
  been 
  unimpaired 
  up 
  to 
  the 
  

   period 
  of 
  deposition, 
  though 
  instances 
  of 
  distortion 
  by 
  subsequent 
  

   compression 
  are 
  not 
  unfrequent. 
  The 
  specimens 
  are 
  found 
  on 
  the 
  

   surfaces 
  of 
  the 
  laminae, 
  usually 
  slightly 
  in 
  relief. 
  They 
  almost 
  

   invariably 
  retain 
  the 
  finely 
  enamelled 
  surface 
  of 
  the 
  original 
  

   ganoine, 
  and 
  are 
  of 
  a 
  brown 
  colour. 
  Most 
  of 
  the 
  examples 
  found 
  

   present 
  a 
  lateral 
  view, 
  with 
  the 
  dorsal, 
  anal, 
  and 
  caudal 
  fins 
  out- 
  

   spread, 
  and 
  with 
  the 
  trunk 
  uncontorted 
  ; 
  examples 
  with 
  the 
  trunk 
  

   bent 
  upon 
  itself, 
  or 
  what 
  is 
  usually 
  termed 
  contorted, 
  are 
  compara- 
  

   tively 
  rare. 
  Individuals 
  showing 
  the 
  dorsal 
  and 
  ventral 
  aspects 
  

   occasionally 
  occur. 
  Besides 
  the 
  scales, 
  cephalic 
  bones, 
  and 
  fin 
  -rays, 
  

   the 
  interspinous 
  bones 
  of 
  the 
  fins 
  are 
  sometimes 
  preserved 
  ; 
  and 
  

  

  