﻿STEATA 
  OP 
  THE 
  HAMPSHIKE 
  BASIN. 
  471 
  

  

  Fisher, 
  is 
  everywhere 
  recognized 
  as 
  the 
  representative 
  of 
  the 
  Upper 
  

   Eocene. 
  

  

  The 
  series 
  of 
  sands 
  immediately 
  overlying 
  the 
  Barton 
  Clay, 
  and 
  

   and 
  called 
  by 
  the 
  Geological 
  Survey 
  the 
  " 
  Upper 
  Bagshot 
  Sands," 
  

   has 
  long 
  been 
  known 
  by 
  the 
  alternative 
  name 
  of 
  the 
  ' 
  ; 
  Headon-Hill 
  

   Sands 
  ;" 
  and 
  by 
  this 
  name, 
  in 
  order 
  to 
  avoid 
  hopeless 
  confusion, 
  I 
  

   would 
  in 
  the 
  future 
  propose 
  to 
  cail 
  it. 
  

  

  At 
  Whitecliff 
  Bay 
  this 
  series 
  of 
  sands 
  is 
  well 
  exposed, 
  forming 
  a 
  

   mass 
  200 
  feet 
  in 
  thickness, 
  immediately 
  overlying 
  the 
  representative 
  

   of 
  the 
  Barton 
  Clay. 
  It 
  is 
  almost 
  equally 
  well 
  seen 
  at 
  Headon 
  Hill, 
  

   where 
  its 
  thickness 
  has 
  been 
  variously 
  estimated 
  at 
  from 
  100 
  to 
  200 
  

   feet. 
  

  

  On 
  the 
  Hampshire 
  coast 
  these 
  sands 
  are 
  exposed 
  between 
  Long- 
  

   Mead 
  End 
  and 
  Beacon 
  Bunny, 
  and 
  again 
  at 
  Eaglehurst 
  near 
  Calshot, 
  

   and 
  they 
  have 
  been 
  dug 
  at 
  many 
  localities 
  inland. 
  

  

  At 
  "Whitecliff 
  Bay 
  the 
  sands 
  in 
  question 
  are 
  generally 
  quite 
  unfossi- 
  

   liferous 
  ; 
  but 
  the 
  late 
  Mr. 
  Bichard 
  Gibbs, 
  the 
  excellent 
  fossil-collector 
  

   of 
  the 
  Geological 
  Survey, 
  found 
  a 
  band 
  in 
  which 
  a 
  number 
  of 
  ferru- 
  

   ginous 
  casts 
  of 
  shells 
  were 
  recognizable. 
  These 
  were 
  too 
  friable 
  for 
  

   removal 
  ; 
  but 
  Professor 
  Edward 
  Eorbes 
  examined 
  them 
  in 
  situ, 
  and 
  

   recognized 
  them 
  as 
  belonging 
  to 
  the 
  marine 
  genera 
  Cardium*, 
  

   PanojHza, 
  and 
  Tellina, 
  and 
  stated 
  that 
  so 
  far 
  as 
  these 
  forms 
  were 
  

   determinable 
  they 
  appeared 
  to 
  be 
  identical 
  with 
  species 
  found 
  in 
  

   the 
  underlying 
  Barton 
  Clay. 
  

  

  At 
  Headon 
  Hill 
  and 
  at 
  Eaglehurst, 
  only 
  comminuted 
  and 
  water- 
  

   worn 
  fragments 
  of 
  shells 
  occur 
  in 
  these 
  sands 
  ; 
  but 
  at 
  Long-Mead 
  

   End 
  a 
  band 
  near 
  the 
  top 
  of 
  these 
  sands 
  contains 
  a 
  tolerably 
  

   abundant 
  fauna.' 
  The 
  beds 
  are 
  evidently 
  of 
  brackish-water 
  origin 
  ; 
  

   for 
  both 
  marine 
  and 
  freshwater 
  forms 
  occur 
  in 
  considerable 
  abun- 
  

   dance 
  in 
  them. 
  

  

  These 
  brackish- 
  water 
  Headon-Hill 
  Sands, 
  then, 
  are 
  intermediate 
  

   in 
  position 
  between 
  the 
  marine 
  Barton 
  Clays 
  below 
  and 
  the 
  fresh- 
  

   water 
  Headon-Hill 
  strata 
  above. 
  They 
  represent 
  the 
  passage 
  from 
  

   marine 
  to 
  freshwater 
  conditions 
  ; 
  and 
  that 
  they 
  are 
  equally 
  related 
  to 
  

   both 
  these 
  deposits 
  is 
  shown 
  by 
  the 
  fact 
  that 
  Barton 
  and 
  Headon 
  

   forms 
  occur 
  in 
  them 
  in 
  about 
  equal 
  proportions 
  f. 
  

  

  Above 
  the 
  Headon-Hill 
  Sands 
  we 
  find 
  at 
  Whitecliff 
  Bay 
  a 
  series 
  

   of 
  clays 
  with 
  bands 
  of 
  lignite 
  attaining 
  a 
  thickness 
  of 
  about 
  40 
  

   feet. 
  The 
  fossils 
  found 
  in 
  these 
  beds 
  appear 
  to 
  be 
  entirely 
  of 
  

  

  * 
  Mem. 
  Geol. 
  Surv., 
  The 
  Geology 
  of 
  the 
  Isle 
  of 
  Wight, 
  1862.. 
  p. 
  51 
  : 
  Car- 
  

   dinia 
  here 
  is 
  clearly 
  a 
  misprint 
  for 
  Cardiura. 
  

  

  t 
  Mr. 
  Tawney 
  has 
  recently 
  stated 
  that, 
  of 
  28 
  species 
  of 
  shells 
  found 
  by 
  him 
  

   at 
  Long-Mead 
  End, 
  only 
  21 
  per 
  cent 
  were 
  Headon 
  forms, 
  while 
  35 
  per 
  cent, 
  

   were 
  Barton 
  forms. 
  He 
  therefore 
  argues 
  -that 
  the 
  Headon-Hill 
  Sands 
  have 
  

   closer 
  affinities 
  with 
  the 
  underlying 
  Barton 
  than 
  with 
  the 
  overlying 
  Headon 
  

   Clays. 
  But 
  in 
  a 
  comparison 
  of 
  this 
  kind 
  every 
  thing 
  depends 
  on 
  the 
  identi- 
  

   fication 
  of 
  species 
  ; 
  and 
  in 
  some 
  cases 
  Mr. 
  Tawney's 
  identifications 
  differ 
  from 
  

   my 
  own, 
  and, 
  I 
  believe, 
  from 
  those 
  of 
  other 
  paleontologists 
  both 
  in 
  England 
  

   and 
  on 
  the 
  continent. 
  

  

  The 
  study 
  of 
  the 
  fauna 
  appears 
  to 
  me 
  to 
  show 
  that 
  the 
  beds 
  are 
  almost 
  exactly 
  

   intermediate 
  in 
  age, 
  as 
  they 
  are 
  in 
  position, 
  between 
  the 
  Barton 
  and 
  the 
  Hea- 
  

   don 
  Clays. 
  

  

  