﻿346 
  F. 
  Q. 
  H. 
  PKICE 
  ON 
  THE 
  GAULT 
  OF 
  FOLKESTONE. 
  

  

  The 
  total 
  thickness 
  of 
  this 
  bed 
  from 
  the 
  top 
  of 
  the 
  Upper 
  Neoco- 
  

   mian 
  beds, 
  i. 
  e. 
  the 
  Folkestone-beds 
  of 
  the 
  Lower 
  Greensand, 
  to 
  a 
  

   hard 
  seam 
  of 
  nodules 
  and 
  crushed 
  band 
  of 
  fossils 
  is 
  10 
  feet 
  1 
  inch. 
  

  

  This 
  bed 
  may 
  be 
  considered 
  the 
  zone 
  of 
  Ammonites 
  interruptus, 
  

   Erug., 
  as 
  that 
  well-known 
  and 
  varied 
  form 
  occurs 
  in 
  this 
  bed 
  and 
  in 
  

   no 
  other, 
  excepting 
  in 
  the 
  band 
  immediately 
  above, 
  which 
  is 
  only 
  1 
  

   inch 
  in 
  thickness. 
  

  

  The 
  following 
  are 
  the 
  synonyma 
  of 
  Ammonites 
  interruptus, 
  Bru- 
  

   gniere, 
  1792 
  : 
  — 
  Ammonites 
  serratus, 
  Parkinson 
  ; 
  A. 
  dentatus, 
  Sow. 
  ; 
  

   A. 
  noricus, 
  De 
  Haan 
  ; 
  A. 
  dentatus, 
  Fitton 
  ; 
  A. 
  Deluci, 
  D'Orb. 
  ; 
  A. 
  

   Ghcibreyanus, 
  Henevier 
  ; 
  A. 
  Benettianus, 
  Bow. 
  

  

  Bed 
  II. 
  

  

  may 
  be 
  considered 
  the 
  bottom 
  bed 
  of 
  the 
  Gaulfc, 
  commencing 
  with 
  

   a 
  band 
  of 
  crushed 
  fossils 
  one 
  inch 
  in 
  thickness, 
  which 
  has 
  a 
  line 
  of 
  

   phosphatic 
  nodules 
  running 
  through 
  it. 
  

  

  The 
  clay 
  of 
  this 
  bed 
  is 
  of 
  a 
  very 
  dark 
  colour, 
  in 
  faet, 
  very 
  nearly 
  

   approaching 
  to 
  black 
  when 
  moist, 
  and 
  is 
  somewhat 
  hard. 
  

  

  It 
  is 
  remarkable 
  for 
  the 
  deep 
  rich 
  colour 
  of 
  its 
  fossils, 
  and 
  for 
  its 
  

   containing 
  several 
  species 
  peculiar 
  to 
  it. 
  

  

  At 
  a 
  distance 
  of 
  three 
  inches 
  upwards 
  from 
  the 
  last-mentioned 
  

   band, 
  a 
  line 
  of 
  selenite 
  in 
  large 
  pieces 
  occurs 
  ; 
  this 
  mineral 
  is 
  not 
  

   met 
  with 
  in 
  any 
  other 
  part 
  of 
  the 
  Gault, 
  and 
  only 
  in 
  the 
  position 
  

   here 
  indicated 
  in 
  bed 
  II. 
  

  

  One 
  foot 
  above 
  the 
  selenite 
  a 
  line 
  of 
  phosphatic 
  nodules 
  occurs 
  ; 
  

   the 
  space 
  between 
  these 
  two 
  is 
  the 
  horizon 
  of 
  Aporrhais 
  calcarata, 
  

   D'Orb., 
  which 
  beautiful 
  little 
  Gasteropod 
  is 
  not 
  met 
  with 
  elsewhere 
  

   in 
  the 
  Gault. 
  Turrilites 
  elegans 
  and 
  Ancyloceras 
  spinigerum 
  like- 
  

   wise 
  occur 
  in 
  this 
  horizon 
  and 
  are 
  not 
  again 
  seen. 
  

  

  The 
  following 
  species 
  are 
  peculiar 
  to 
  this 
  bed 
  : 
  — 
  

  

  Fusus 
  Itierianus, 
  D' 
  Orb. 
  Myacites, 
  sp. 
  

  

  Cerithium 
  trimonile, 
  Mich. 
  Pectunculus, 
  sp. 
  

  

  Narica 
  cancellata, 
  Chemn. 
  Nucula 
  De 
  Eancei, 
  Price. 
  

  

  Corbula 
  gaultina, 
  Pict. 
  et 
  Camp. 
  Pollicipes 
  rigidus, 
  Sow. 
  

  

  and 
  a 
  variety 
  of 
  Ammonites 
  auritus 
  having 
  long 
  tubercles, 
  which 
  

   may 
  perhaps 
  be 
  a 
  distinct 
  species. 
  

  

  The 
  total 
  thickness 
  of 
  this 
  bed, 
  measured 
  to 
  the 
  base 
  of 
  the 
  " 
  light 
  

   bed 
  " 
  No. 
  III., 
  is 
  4 
  feet 
  2 
  inches. 
  

  

  The 
  rich 
  colour 
  on 
  the 
  shells 
  of 
  the 
  fossils 
  from 
  this 
  zone 
  is, 
  no 
  

   doubt, 
  due 
  to 
  the 
  very 
  large 
  percentage 
  of 
  iron 
  in 
  the 
  form 
  of 
  oxides, 
  

   and 
  to 
  the 
  comparatively 
  small 
  percentage 
  of 
  carbonate 
  of 
  lime 
  met 
  

   with 
  in 
  the 
  clay 
  of 
  this 
  bed. 
  

  

  My 
  friend 
  Mr. 
  W. 
  H. 
  Hudleston, 
  to 
  whom 
  my 
  best 
  thanks 
  are 
  due, 
  

   has 
  given 
  me 
  the 
  following 
  analysis 
  of 
  the 
  clay 
  of 
  bed 
  II. 
  : 
  — 
  

  

  " 
  The 
  Gault 
  of 
  this 
  bed 
  consists 
  of 
  a 
  grey 
  marly 
  clay 
  ; 
  constituent 
  

   particles 
  extremely 
  fine 
  and 
  close 
  ; 
  nothing 
  granular 
  observed 
  except 
  

   a 
  few 
  specks 
  of 
  pyrites 
  and 
  a 
  considerable 
  amount 
  of 
  organic 
  matter. 
  

   Dried 
  at 
  100 
  C. 
  it 
  contains 
  

  

  