﻿470 
  TEOF. 
  J. 
  W. 
  JUDD 
  ON 
  THE 
  EOCENE 
  AND 
  OLIGOCEXE 
  

  

  area 
  is 
  still 
  a 
  subject 
  of 
  much 
  doubt; 
  and 
  this 
  arises 
  principally 
  from 
  

   the 
  fact 
  of 
  tbe 
  unfossiliferous 
  character 
  of 
  these 
  last-mentioned 
  strata. 
  

   According 
  to 
  the 
  views 
  of 
  the 
  officers 
  of 
  the 
  Geological 
  Survey, 
  660 
  

   feet 
  of 
  the 
  beds 
  seen 
  at 
  Alum 
  Bay 
  ought 
  to 
  be 
  ranked 
  as 
  Lower 
  

   Bagshot, 
  while 
  Mr. 
  Gardner 
  would 
  restrict 
  that 
  name 
  to 
  73 
  feet 
  of 
  

   those 
  beds. 
  What, 
  if 
  any 
  such 
  exist, 
  are 
  the 
  Hampshire 
  repre- 
  

   sentatives 
  of 
  the 
  Upper 
  Bagshots 
  of 
  the 
  London 
  basin, 
  is 
  a 
  question 
  

   about 
  which 
  there 
  is 
  still 
  greater 
  aud 
  apparently 
  hopeless 
  divergence 
  

   of 
  opinion. 
  

  

  From 
  this 
  state 
  of 
  confusion 
  into 
  which 
  the 
  nomenclature 
  of 
  the 
  

   Middle 
  and 
  Upper 
  Eocenes 
  of 
  the 
  Hampshire 
  basin 
  has 
  unfor- 
  

   tunately 
  fallen, 
  there 
  is 
  one 
  and, 
  as 
  it 
  appears 
  to 
  me, 
  only 
  one 
  

   means 
  of 
  escape. 
  It 
  is 
  clear 
  that 
  the 
  Upper 
  and 
  Lower 
  Bagshots 
  of 
  

   the 
  London 
  basin 
  have 
  not 
  yielded 
  a 
  sufficient 
  number 
  of 
  well- 
  

   preserved 
  organic 
  remains 
  to 
  enable 
  us 
  to 
  determine 
  their 
  exact 
  

   place 
  in 
  the 
  geological 
  series. 
  The 
  naming 
  of 
  beds 
  in 
  the 
  Hampshire 
  

   basin, 
  the 
  age 
  of 
  which 
  is 
  clearly 
  determinable, 
  after 
  these 
  doubtful 
  

   deposits, 
  has 
  been 
  the 
  source'of 
  an 
  immense 
  amount 
  of 
  confusion 
  

   in 
  the 
  past. 
  I 
  would 
  therefore 
  advocate, 
  as 
  the 
  only 
  way 
  of 
  getting 
  

   rid 
  of 
  this 
  confusion, 
  the 
  total 
  abandonment 
  of 
  the 
  terms 
  Upper 
  

   and 
  Lower 
  Bagshot, 
  as 
  applied 
  to 
  strata 
  in 
  the 
  Hampshire 
  basin. 
  

  

  The 
  beds 
  in 
  the 
  Hampshire 
  basin 
  to 
  which 
  the 
  term 
  Lower 
  Bag- 
  

   shot 
  has 
  been 
  restricted 
  by 
  Mr. 
  Prestwich 
  and 
  by 
  Mr. 
  Gardner, 
  

   were 
  formerly 
  called 
  " 
  the 
  Lower 
  Bracklesham 
  Sands 
  " 
  by 
  the 
  first- 
  

   named 
  author. 
  This 
  name 
  appears 
  liable 
  to 
  be 
  misundersood, 
  and 
  

   has 
  been 
  withdrawn 
  by 
  its 
  author. 
  I 
  would 
  venture 
  therefore 
  to 
  

   suggest 
  as 
  a 
  convenient 
  name 
  for 
  this 
  series 
  of 
  beds, 
  which 
  is 
  

   represented 
  in 
  Whitecliff 
  Bay 
  by 
  Mr. 
  Prcstwich's 
  bed 
  5, 
  in 
  Alum 
  

   Bay 
  by 
  his 
  beds 
  15 
  to 
  18, 
  and 
  on 
  the 
  Hampshire 
  coast 
  by 
  the 
  

   sands 
  and 
  pipe-clays 
  of 
  Poole, 
  Corfe, 
  Branksea 
  Island, 
  and 
  Studland 
  

   Bay, 
  the 
  term 
  " 
  Studland 
  Series." 
  The 
  Studland 
  beds 
  are 
  of 
  purely 
  

   freshwater 
  origin 
  ; 
  and 
  they 
  yield 
  an 
  abundant 
  flora, 
  which 
  has 
  now 
  

   been 
  shown 
  to 
  be 
  perfectly 
  distinct 
  from 
  that 
  of 
  the 
  overlying 
  

   Bournemouth 
  beds 
  *. 
  

  

  The 
  Studland 
  Series 
  forms 
  the 
  lower 
  part 
  of 
  the 
  Middle 
  Eocene 
  

   in 
  the 
  Hampshire 
  basin; 
  and 
  the 
  upper 
  part 
  of 
  that 
  division 
  is 
  

   formed 
  by 
  the 
  mass 
  of 
  strata 
  which 
  in 
  its 
  easterly 
  development 
  is 
  

   purely 
  marine 
  but 
  in 
  its 
  westerly 
  development 
  passes 
  into 
  brackish- 
  

   water 
  and 
  freshwater 
  deposits. 
  The 
  way 
  in 
  which 
  this 
  takes 
  place 
  

   has 
  been 
  admirably 
  illustrated 
  in 
  the 
  memoirs 
  of 
  Mr. 
  Prestwich 
  and 
  

   Mr. 
  Gardner. 
  The 
  marine 
  type 
  of 
  this 
  formation 
  is 
  the 
  Bracklesham, 
  

   the 
  freshwater 
  the 
  Bournemouth 
  series. 
  Both 
  the 
  marine 
  fauna 
  

   and 
  the 
  terrestrial 
  flora 
  of 
  these 
  beds 
  seem 
  to 
  be 
  highly 
  charac- 
  

   teristic, 
  so 
  as 
  to 
  clearly 
  distinguish 
  it 
  alike 
  from 
  the 
  underlying 
  and 
  

   overlying 
  deposits. 
  

  

  The 
  Barton 
  Clay, 
  of 
  which 
  the 
  limits, 
  as 
  defined 
  by 
  Mr. 
  Prest- 
  

   wich, 
  appear 
  to 
  me 
  to 
  agree 
  much 
  more 
  closely 
  with 
  the 
  conti- 
  

   nental 
  classification 
  than 
  does 
  the 
  grouping 
  proposed 
  by 
  Mr. 
  0. 
  

  

  * 
  Pal. 
  Soc., 
  British 
  Eocene 
  Flora, 
  1879, 
  p. 
  16. 
  

  

  