﻿346 
  PILOCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  [Apr. 
  27, 
  

  

  and 
  it 
  was 
  in 
  working 
  these 
  lower 
  and 
  inferior 
  strata 
  that 
  the 
  great 
  

   bulk 
  of 
  the 
  fossil 
  Pish 
  were 
  discovered, 
  most 
  of 
  them 
  having 
  been 
  

   found 
  in 
  one 
  bed, 
  or 
  zone 
  of 
  beds, 
  of 
  limestone 
  ; 
  there, 
  nevertheless, 
  

   being 
  several 
  instances 
  of 
  their 
  occurrence 
  both 
  above 
  and 
  below 
  

   that 
  horizon. 
  

  

  Soon 
  after 
  their 
  discovery 
  in 
  the 
  new 
  quarry, 
  another 
  or 
  the 
  same 
  

   anticlinal 
  brought 
  up 
  the 
  equivalent 
  strata 
  in 
  the 
  old 
  quarry, 
  about 
  

   half 
  a 
  furlong 
  to 
  the 
  south 
  ; 
  and 
  it 
  was 
  not 
  long 
  before 
  the 
  same 
  

   fossils 
  were 
  met 
  with 
  there, 
  besides 
  other 
  species 
  that 
  the 
  first 
  

   locality 
  had 
  not 
  yielded. 
  

  

  The 
  same 
  Fish-bed 
  would 
  appear 
  also 
  to 
  extend 
  considerably 
  to 
  

   the 
  north-east 
  ; 
  for 
  I 
  have 
  obtained 
  the 
  tail-half 
  of 
  a 
  small 
  fish 
  from 
  

   a 
  stratum 
  of 
  limestone 
  in 
  Marsden 
  Bay, 
  occupying 
  the 
  same 
  strati- 
  

   graphical 
  position 
  as 
  the 
  Fulwell 
  Fish-bed. 
  

  

  The 
  Magnesian 
  Limestone 
  worked 
  in 
  the 
  Fulwell 
  quarries 
  belongs 
  

   to 
  the 
  higher 
  portion 
  of 
  the 
  Permian 
  series, 
  or, 
  to 
  speak 
  with 
  pre- 
  

   cision, 
  to 
  the 
  " 
  Upper 
  Limestone 
  " 
  of 
  the 
  classification 
  proposed 
  by 
  

   Mr. 
  Howse, 
  or 
  to 
  the 
  Crystalline 
  and 
  Concretionary 
  Limestone 
  of 
  

   Professor 
  King's 
  arrangement. 
  But 
  it 
  must 
  be 
  further 
  observed 
  that 
  

   the 
  Upper 
  Limestone 
  of 
  Durham 
  is 
  composed 
  of 
  two 
  portions, 
  the 
  

   higher 
  being 
  yellow, 
  friable, 
  or 
  compact, 
  or 
  oolitic, 
  and 
  thin-bedded, 
  

   while 
  the 
  lower 
  is 
  of 
  various 
  shades 
  of 
  yellow 
  and 
  grey, 
  highly 
  

   concretionary, 
  compact, 
  or 
  friable, 
  and 
  thick-bedded. 
  It 
  is 
  the 
  

   latter 
  portion 
  that 
  is 
  worked 
  in 
  the 
  quarries 
  of 
  Fulwell 
  Hill, 
  that 
  

   district 
  being 
  situate 
  beyond 
  the 
  outcrop 
  of 
  the 
  higher 
  strata. 
  The 
  

   lower 
  portion, 
  which, 
  for 
  the 
  sake 
  of 
  convenience, 
  I 
  shall 
  term 
  the 
  

   Fulwell 
  beds, 
  has 
  been 
  further 
  subdivided 
  by 
  the 
  quarrymen 
  into 
  

   several 
  minor 
  groups. 
  These 
  it 
  will 
  be 
  well 
  to 
  mention, 
  as 
  they 
  

   serve 
  to 
  mark 
  with 
  greater 
  exactness 
  the 
  vertical 
  distribution 
  of 
  the 
  

   fossils 
  I 
  am 
  about 
  to 
  describe. 
  

  

  Below 
  the 
  higher 
  thin-bedded 
  yellow 
  limestone 
  is 
  a 
  series 
  of 
  

   thick 
  beds 
  of 
  hard, 
  subcrystalline, 
  grey 
  or 
  whitish 
  -grey 
  limestone, 
  

   associated 
  with 
  or 
  passing 
  into 
  strata 
  of 
  conglomerated 
  or 
  botry- 
  

   oidal 
  and 
  very 
  friable 
  white 
  limestone 
  ; 
  this 
  group 
  is 
  the 
  " 
  White 
  

   Stone" 
  of 
  the 
  Fulwell 
  quarrymen. 
  Immediately 
  below 
  is 
  about 
  

   three 
  feet 
  of 
  dark-grey, 
  highly 
  crystalline, 
  and 
  conglomerated 
  lime- 
  

   stone, 
  with 
  beautiful 
  (metastatic) 
  crystals 
  of 
  calc-spar, 
  and 
  crystal- 
  

   loids 
  of 
  limestone 
  ; 
  this 
  is 
  named 
  the 
  " 
  Black 
  Shell." 
  Underlying 
  

   it 
  is 
  generally 
  a 
  bed 
  of 
  soft 
  friable 
  limestone 
  with 
  conglobations 
  ; 
  

   and 
  then 
  follows 
  from 
  twenty 
  to 
  twenty-five 
  feet 
  of 
  thick-bedded 
  

   crystalline 
  and 
  concretionary 
  limestone, 
  which, 
  from 
  its 
  peculiar 
  

   structure, 
  is 
  termed 
  the 
  " 
  Honeycomb 
  Limestone 
  or 
  Main 
  Stone." 
  

   Separated 
  from 
  the 
  Main 
  Stone 
  by 
  about 
  two 
  feet 
  of 
  conglobated 
  

   limestone, 
  follows 
  nine 
  feet 
  of 
  white 
  or 
  yellowish, 
  very 
  soft 
  and 
  

   friable 
  limestone, 
  which 
  is 
  the 
  great 
  " 
  Marl 
  Bed" 
  of 
  the 
  quarrymen. 
  

   Under 
  it 
  is 
  about 
  nine 
  feet 
  of 
  thinner-bedded, 
  often 
  laminated, 
  

   compact, 
  yellow 
  or 
  brown 
  limestone, 
  called 
  the 
  fc 
  'Dun 
  Stone." 
  This 
  

   is 
  underlain 
  by 
  eight 
  feet 
  of 
  highly 
  concretionary 
  and 
  crystalline, 
  

   coralloidal, 
  and 
  laminated 
  limestone, 
  designated 
  the 
  " 
  Grey 
  Stone." 
  

   Immediately 
  under 
  this 
  is 
  two 
  feet 
  of 
  laminated 
  limestone, 
  which 
  I 
  

  

  