﻿SUBDIVISIONS 
  OE 
  THE 
  SPEETON 
  CLAY. 
  605 
  

  

  Bed 
  Chalk 
  existing 
  at 
  the 
  top 
  of 
  the 
  Speeton 
  Clay 
  has 
  been 
  once 
  or 
  

   twice 
  suggested, 
  but 
  has 
  been 
  regarded 
  as 
  untenable. 
  In 
  these 
  

   beds, 
  however, 
  we 
  have 
  probably 
  a 
  representative 
  of 
  the 
  Lower 
  

   Gault, 
  while 
  the 
  Ked 
  Chalk 
  itself 
  may 
  represent 
  the 
  Upper 
  division 
  

   of 
  the 
  Gault. 
  

  

  With 
  these 
  beds 
  I 
  conclude 
  my 
  description 
  of 
  the 
  Speeton 
  Clay 
  ; 
  

   and 
  if 
  I 
  have 
  entered 
  at 
  great 
  detail 
  into 
  the 
  discussion 
  of 
  the 
  

   various 
  horizons, 
  it 
  is 
  because 
  I 
  know 
  by 
  experience 
  how 
  difficult 
  

   it 
  would 
  be 
  for 
  a 
  student 
  unacquainted 
  with 
  the 
  locality, 
  needing 
  

   these 
  details, 
  to 
  acquire 
  them. 
  

  

  Summary. 
  

  

  In 
  these 
  descriptions 
  the 
  points 
  to 
  which 
  I 
  would 
  especially 
  draw 
  

   attention 
  may 
  be 
  summed 
  up 
  as 
  follows 
  : 
  — 
  

  

  1. 
  The 
  sandy 
  blue 
  shales 
  now 
  seen 
  in 
  the 
  cliff 
  near 
  Piley 
  are 
  

   not 
  in 
  place, 
  but 
  are 
  " 
  bouldered 
  " 
  in 
  drift 
  ; 
  and 
  most, 
  if 
  not 
  all 
  

   of 
  them, 
  are 
  of 
  Liassic 
  age. 
  

  

  2. 
  The 
  bituminous 
  shales 
  (Upper 
  Kimeridge) 
  extend 
  upwards 
  to 
  

   the 
  "Coprolite-bed" 
  without 
  the 
  intervention 
  of 
  the 
  beds 
  described 
  

   as 
  " 
  Portlandian." 
  

  

  3. 
  There 
  is 
  no 
  unconformity 
  traceable 
  at 
  the 
  horizon 
  of 
  the 
  

   Coprolite-bed. 
  

  

  4. 
  It 
  is 
  in 
  the 
  " 
  Zone 
  of 
  Belemnites 
  lateralis" 
  as 
  defined 
  in 
  this 
  

   paper 
  ( 
  = 
  the 
  " 
  Astierianus-zone 
  of 
  the 
  Lower 
  Neocomian 
  " 
  of 
  Judd), 
  

   that 
  we 
  find 
  the 
  " 
  Portlandian 
  beds 
  " 
  of 
  Leckenby, 
  this 
  zone 
  having 
  

   marked 
  Jurassic 
  affinities. 
  

  

  5. 
  A 
  very 
  well-marked 
  band 
  of 
  nodules 
  with 
  scattered 
  coprolites 
  

   caps 
  the 
  " 
  Zone 
  of 
  Bel. 
  lateralis," 
  and 
  this 
  band 
  constituted 
  the 
  

   " 
  Coprolite-bed 
  " 
  of 
  Leckenby, 
  though 
  not 
  of 
  Judd. 
  

  

  6. 
  The 
  thickness 
  of 
  clay 
  between 
  the 
  bituminous 
  shales 
  and 
  the 
  

   Bed 
  Chalk 
  is 
  probably 
  really 
  under 
  300 
  feet. 
  

  

  7. 
  The 
  distribution 
  which 
  has 
  been 
  assigned 
  to 
  some 
  of 
  the 
  cha- 
  

   racteristic 
  fossils 
  of 
  the 
  clays 
  needs 
  revision 
  and 
  alteration 
  ; 
  among 
  

   the 
  species 
  thus 
  affected 
  are 
  : 
  — 
  Ammonites 
  Astierianus, 
  Amm. 
  rotula, 
  

   Amm. 
  sjjeetonensis, 
  Amm. 
  Gravesianus, 
  Toocaster 
  complanatus, 
  Tro- 
  

   cJms 
  pulcherrimus, 
  Inoceramus 
  venustulus, 
  and 
  others. 
  

  

  8. 
  The 
  term 
  " 
  Middle 
  Neocomian," 
  as 
  hitherto 
  defined 
  in 
  the 
  

   Speeton 
  section, 
  is 
  unnecessary 
  and 
  misleading, 
  since 
  the 
  beds 
  which 
  

   have 
  received 
  this 
  name 
  have 
  a 
  " 
  Lower 
  Neocomian 
  " 
  fauna 
  above 
  as 
  

   well 
  as 
  below 
  them, 
  and 
  do 
  not 
  seem 
  in 
  themselves 
  to 
  contain 
  any 
  

   peculiar 
  or 
  distinctive 
  types. 
  

  

  9. 
  As 
  stated 
  by 
  Meyer, 
  marly 
  shales 
  exist 
  between 
  the 
  Red 
  Chalk 
  

   and 
  the 
  Speeton 
  Clays, 
  strongly 
  suggestive 
  of 
  a 
  passage 
  from 
  one 
  to 
  

   the 
  other. 
  

  

  10. 
  The 
  section 
  may 
  be 
  very 
  conveniently 
  divided 
  into 
  life-zones 
  

   by 
  its 
  Belemnites. 
  

  

  Conclusion. 
  

  

  In 
  working 
  on 
  my 
  subject 
  certain 
  inferences 
  have 
  presented 
  them- 
  

   selves, 
  which 
  I 
  append, 
  as 
  it 
  may 
  be 
  that 
  among 
  them 
  are 
  sug- 
  

  

  