﻿354 
  F. 
  G. 
  H. 
  PRICE 
  ON 
  THE 
  GAULT 
  OF 
  FOLKESTONE. 
  

  

  marly 
  character 
  as 
  that 
  below, 
  only 
  much 
  mixed 
  with 
  grains 
  of 
  sand 
  

   for 
  the 
  first 
  few 
  feet. 
  

  

  The 
  bed 
  No. 
  XI. 
  contains 
  but 
  few 
  fossils 
  which 
  are 
  entitled 
  to 
  

   be 
  regarded 
  as 
  peculiar 
  to 
  it; 
  they 
  are 
  as 
  follows 
  : 
  — 
  Ostrea 
  frons, 
  

   Ptychoceras, 
  Hylospongia 
  of 
  Sollas, 
  only 
  met 
  with 
  just 
  below 
  

   the 
  greensand 
  seam 
  ; 
  Inoceramus 
  Crispii, 
  a 
  large 
  smooth 
  species, 
  

   and 
  Ammonites 
  varians 
  ? 
  occurring 
  above 
  the 
  greensand 
  seam. 
  

  

  Ammonites 
  rostratus 
  is 
  found 
  of 
  large 
  size 
  in 
  this 
  zone, 
  often 
  

   having 
  Plicatula 
  sigillina 
  adhering 
  to 
  it. 
  I 
  have 
  frequently 
  met 
  

   with 
  this 
  Ammonite 
  measuring 
  as 
  much 
  as 
  12 
  inches 
  in 
  diameter. 
  

   Ammonites 
  Ooodhalli 
  likewise 
  attains 
  a 
  very 
  large 
  diameter. 
  

   Belemnites 
  are 
  rarely 
  found 
  at 
  all 
  above 
  the 
  greensand 
  seam. 
  

   For 
  the 
  following 
  analysis 
  of 
  the 
  Gault 
  of 
  bed 
  XI. 
  I 
  am 
  indebted 
  

   to 
  Mr. 
  W. 
  H. 
  Hudleston, 
  who 
  has 
  taken 
  considerable 
  time 
  and 
  

   trouble 
  in 
  working 
  it 
  out 
  for 
  me. 
  

  

  " 
  It 
  consists 
  of 
  a 
  pale 
  grey 
  marl, 
  the 
  particles 
  in 
  a 
  minute 
  state 
  of 
  

   subdivision. 
  The 
  bulk 
  of 
  the 
  mass 
  is 
  a 
  mixture 
  of 
  chalk 
  and 
  clay 
  ; 
  a 
  

   very 
  few, 
  and 
  extremely 
  small, 
  quartz 
  grains, 
  and, 
  after 
  treatment 
  

   with 
  acid, 
  one 
  or 
  two 
  translucent 
  greenish 
  grains 
  were 
  observed 
  ; 
  

   also 
  small 
  crystals 
  and 
  fragments 
  of 
  pyrites. 
  

   " 
  Dried 
  at 
  100° 
  C. 
  this 
  sample 
  contains 
  : 
  — 
  

  

  per 
  cent. 
  

  

  Water 
  and 
  organic 
  matter 
  6*75 
  

  

  Carbonate 
  of 
  lime 
  26'45 
  

  

  Clay-sand 
  and 
  silica, 
  oxides 
  of 
  iron, 
  pyrites, 
  &c. 
  . 
  . 
  65'95 
  

  

  Chloride 
  of 
  sodium 
  ] 
  

  

  Sulphate 
  of 
  lime 
  V 
  found, 
  but 
  not 
  estimated 
  . 
  . 
  *81 
  

  

  Carbonate 
  of 
  magnesia 
  ) 
  

  

  Phosphoric 
  acid 
  -04 
  

  

  100-00 
  

   Metallic 
  iron 
  2-55 
  per 
  cent." 
  

  

  There 
  is 
  an 
  enormous 
  field 
  open 
  in 
  the 
  Gault 
  to 
  the 
  palaeontolo- 
  

   gist 
  ; 
  and 
  it 
  is 
  to 
  be 
  hoped 
  that 
  the 
  day 
  is 
  not 
  far 
  distant 
  when 
  the 
  

   large 
  quantity 
  of 
  material 
  obtained 
  and 
  still 
  to 
  be 
  obtained 
  from 
  

   the 
  Gault 
  in 
  various 
  parts 
  of 
  England, 
  more 
  especially 
  at 
  Folkestone, 
  

   will 
  be 
  exhausted, 
  arid 
  some 
  valuable 
  monographs 
  will 
  be 
  prepared 
  for 
  

   the 
  Palaeontographical 
  Society. 
  

  

  The 
  data 
  the 
  palaeontologist 
  has 
  at 
  present 
  to 
  fall 
  back 
  upon 
  are 
  

   principally 
  works, 
  very 
  able 
  in 
  their 
  way, 
  which 
  have 
  been 
  pro- 
  

   duced 
  by 
  foreign 
  geologists 
  upon 
  foreign 
  species. 
  Those 
  few 
  scattered 
  

   specimens 
  from 
  the 
  Gault 
  that 
  have 
  been 
  figured 
  by 
  English 
  authors 
  

   have 
  been 
  mostly 
  from 
  very 
  imperfect 
  specimens. 
  

  

  Besides 
  the 
  fossils 
  here 
  enumerated, 
  there 
  are 
  many 
  forms 
  which 
  

   it 
  is 
  difficult 
  at 
  present 
  to 
  assign 
  to 
  any 
  genus. 
  

  

  I 
  may 
  add 
  that 
  there 
  are 
  many 
  fish-remains 
  (which 
  occur 
  mostly 
  

   in 
  the 
  upper 
  division) 
  wholly 
  undescribed. 
  The 
  species 
  of 
  the 
  class 
  

   Cephalopoda 
  require 
  entirely 
  reworking 
  out, 
  more 
  particularly 
  the 
  

   Hamites, 
  which 
  have 
  been 
  described 
  by 
  Messrs. 
  Sowerby, 
  Pictet, 
  

  

  