﻿STRATA 
  OP 
  THE 
  HAMPSHIRE 
  BASIN. 
  475 
  

  

  feet. 
  

  

  (6) 
  White 
  sands 
  and 
  clays, 
  with 
  " 
  Crocodile-bed" 
  at 
  top 
  ... 
  15 
  

  

  (7) 
  Sandy 
  bed 
  with 
  lignite 
  ("Leaf-bed") 
  3 
  

  

  (8) 
  Greenish 
  sands 
  and 
  clays 
  ("Mammalian 
  bed") 
  with 
  a 
  

  

  band 
  near 
  the 
  base 
  containing 
  estuarine 
  fossils 
  20 
  

  

  (9) 
  "Lignitebed" 
  3^ 
  

  

  (10) 
  Seam 
  of 
  sand 
  crowded 
  with 
  estuarine 
  shells 
  (" 
  Oliva- 
  

  

  bed") 
  1 
  

  

  (11) 
  Sands 
  with 
  occasional 
  brackish-water 
  shells 
  30-40 
  

  

  These 
  beds 
  graduate 
  so 
  imperceptibly 
  into 
  the 
  underlying 
  Barton 
  

   clays 
  that 
  it 
  is 
  difficult 
  to 
  fix 
  the 
  exact 
  limits 
  between 
  them 
  *. 
  

  

  As 
  studied 
  at 
  Hordwell 
  Cliff, 
  then, 
  the 
  Headon 
  sands 
  and 
  clays 
  

   are 
  seen 
  to 
  pass 
  into 
  one 
  another 
  by 
  insensible 
  gradations, 
  they 
  

   are 
  both 
  of 
  estuarine 
  origin, 
  and 
  they 
  contain 
  essentially 
  the 
  same 
  

   fauna. 
  "What 
  that 
  fauna 
  is, 
  there 
  is 
  not 
  the 
  smallest 
  room 
  for 
  doubt. 
  

   The 
  French 
  geologists 
  have 
  long 
  recognized 
  at 
  the 
  top 
  of 
  their 
  Gres 
  

   de 
  Beauchamp, 
  which 
  represents 
  our 
  Barton 
  clay, 
  a 
  series 
  of 
  sands 
  

   well 
  exposed 
  at 
  Mortefontaine, 
  Monneville, 
  and 
  even 
  under 
  Paris 
  

   itself, 
  containing 
  a 
  peculiar 
  assemblage 
  of 
  fossils, 
  and 
  to 
  which 
  the 
  

   name 
  of 
  the 
  zone 
  of 
  Cerithium 
  concavum 
  has 
  been 
  given 
  by 
  Carl 
  

   Mayer 
  and 
  Sandberger. 
  Hebert, 
  Carl 
  Mayer, 
  and 
  many 
  other 
  

   foreign 
  geologists 
  have 
  recognized 
  in 
  our 
  Headon 
  and 
  Hordwell 
  beds 
  

   the 
  representatives 
  of 
  the 
  zone 
  of 
  Cerithium 
  concavum 
  of. 
  the 
  continent. 
  

   As 
  in 
  the 
  continental 
  beds, 
  so 
  in 
  both 
  the 
  Headon 
  sands 
  and 
  clays 
  the 
  

   very 
  characteristic 
  fossil 
  C. 
  concavum 
  occurs 
  in 
  enormous 
  abundance 
  ; 
  

   and 
  many 
  other 
  fossils 
  are 
  common 
  to 
  the 
  English 
  and 
  French 
  de- 
  

   posits. 
  On 
  the 
  question 
  of 
  the 
  position 
  of 
  this 
  zone 
  of 
  Cerithium 
  

   concavum, 
  and 
  the 
  correlation 
  of 
  our 
  Headon 
  and 
  Hordwell 
  beds 
  

   with 
  them, 
  all 
  the 
  most 
  eminent 
  Tertiary 
  geologists 
  of 
  France, 
  Ger- 
  

   many, 
  and 
  Switzerland 
  are 
  perfectly 
  agreed. 
  

  

  At 
  Eaglehurst, 
  near 
  Calshot, 
  variegated 
  clays 
  and 
  sands 
  with 
  

   Potamomya 
  and 
  other 
  freshwater 
  shells 
  are 
  found 
  overlying 
  the 
  

   representatives 
  of 
  the 
  Headon-Hill 
  sands 
  just 
  as 
  at 
  Hordwell. 
  These 
  

   clays 
  are 
  dug 
  in 
  the 
  Solent 
  brick-works 
  ; 
  and 
  by 
  the 
  aid 
  of 
  Mr. 
  E. 
  

   Westlake 
  and 
  Mr. 
  Hooper 
  I 
  have 
  been 
  enabled 
  to 
  recognize 
  among 
  

   the 
  bones 
  found 
  here 
  remains 
  of 
  Crocodilus 
  Hastingsiw 
  and 
  of 
  the 
  

   well-known 
  forms 
  of 
  Trionycc 
  and 
  Emys 
  of 
  Hordwell. 
  

  

  The 
  Headon 
  beds 
  are 
  240 
  feet 
  thick 
  at 
  Whiteclifr 
  Bay; 
  at 
  Alum 
  

   Bay 
  their 
  thickness 
  is 
  variously 
  estimated 
  at 
  from 
  300 
  to 
  400 
  feet 
  : 
  

   at 
  Hordwell 
  they 
  exceed 
  120 
  ; 
  while 
  at 
  Eaglehurst 
  their 
  thickness 
  

   cannot 
  be 
  exactly 
  determined. 
  

  

  The 
  next 
  series 
  of 
  strata 
  exposed 
  at 
  Whitecliff: 
  Bay 
  is 
  the 
  very 
  

   interesting 
  one 
  for 
  which 
  I 
  have 
  proposed 
  the 
  name 
  of 
  the 
  Brocken- 
  

   hurst 
  series. 
  The 
  freshwater 
  Headon 
  clays 
  are 
  suddenly 
  succeeded 
  

  

  * 
  Mr. 
  Searles 
  V. 
  Wood 
  has 
  obligingly 
  furnished 
  me 
  with 
  some 
  notes 
  which 
  he 
  

   made 
  when 
  working 
  in 
  company 
  with 
  his 
  father 
  at 
  Hordwell 
  in 
  the 
  years 
  1843 
  

   and 
  1845. 
  He 
  assures 
  me 
  that 
  the 
  whole 
  of 
  the 
  vertebrate 
  fossils 
  obtained 
  by 
  

   his 
  father, 
  both 
  reptilian 
  and 
  mammalian, 
  were 
  taken 
  from 
  the 
  bed 
  (6) 
  which 
  

   is 
  called 
  the 
  " 
  Crocodile-bed." 
  Vertebrate 
  fossils, 
  however, 
  appear 
  to 
  abound 
  in 
  

   both 
  the 
  divisions 
  (0) 
  and 
  (8). 
  

  

  2k2 
  

  

  