﻿PLIOCENE 
  TERIOD 
  IX 
  EXGLAXD. 
  

  

  691 
  

  

  Bournemouth 
  plateau, 
  and 
  in 
  gravel/ 
  at 
  Dartford 
  Heath, 
  and 
  mam- 
  

   malian 
  remains 
  in 
  the 
  gravel 
  c 
  beneath 
  the 
  Chalky 
  Clay 
  at 
  Birkett 
  

   Wood 
  in 
  the 
  Colne 
  channel, 
  as 
  well 
  as 
  in 
  the 
  mud 
  deposit 
  at 
  Selsey.rich 
  

   in 
  marine 
  shells, 
  described 
  in 
  Stage 
  VI. 
  : 
  but 
  neither 
  implements 
  nor 
  

   mammalian 
  remains 
  are 
  any 
  more 
  evidence 
  of 
  a 
  fluviatile 
  or 
  freshwater 
  

   origin 
  for 
  the 
  gravel 
  containing 
  them 
  than 
  are 
  the 
  subangular 
  flints 
  

   with 
  which 
  they 
  are 
  associated, 
  for 
  the 
  base 
  of 
  the 
  Eed 
  Crag 
  abounds 
  

   with 
  such 
  remains 
  (and 
  much 
  in 
  the 
  condition 
  too 
  in 
  which 
  bones 
  

   are 
  found 
  generally 
  in 
  gravels), 
  and 
  I 
  myself 
  found 
  part 
  of 
  a 
  mamma- 
  

   lian 
  humerus 
  associated 
  with 
  the 
  marine 
  Lamellibranchiata, 
  in 
  the 
  

   position 
  in 
  which 
  these 
  lived 
  with 
  valves 
  united, 
  in 
  the 
  pebbly 
  sand, 
  

   b 
  ./, 
  beneath 
  the 
  Cromer 
  Till 
  at 
  Weybourne. 
  On 
  the 
  other 
  hand, 
  the 
  

   absence 
  of 
  marine 
  shells 
  is 
  (with 
  the 
  exception 
  of 
  the 
  seam 
  in 
  the 
  

   ux^per 
  part 
  of 
  c, 
  which 
  is 
  confined 
  to 
  East 
  Anglia, 
  and 
  due 
  to 
  the 
  

   ploughing-out 
  of 
  an 
  older 
  bed 
  by 
  the 
  Chalky-Clay 
  ice 
  in 
  its 
  advance)* 
  

   the 
  character 
  of 
  all 
  the 
  gravel, 
  whether 
  b\ 
  c, 
  e, 
  or/, 
  everywhere 
  

   except 
  in 
  the 
  North- 
  west 
  of 
  England 
  and 
  the 
  Severn 
  valley 
  ; 
  and 
  even 
  

   there, 
  save 
  in 
  the 
  case 
  where 
  they 
  occur 
  in 
  clay 
  seams 
  intercalated 
  

   in 
  the 
  gravel, 
  as 
  at 
  Ironbridge, 
  these 
  shells, 
  though 
  synchronous, 
  are 
  

   much 
  worn 
  and 
  evidently 
  transported 
  : 
  gravel 
  bottoms 
  apparently 
  

   being 
  adverse 
  to 
  the 
  life 
  of 
  testaceous 
  Mollusca. 
  

  

  These 
  high 
  patches 
  of 
  gravel 
  within 
  the 
  valley 
  of 
  the 
  Medway 
  

   and 
  other 
  Weald 
  rivers, 
  including 
  that 
  of 
  the 
  Tillingbourne 
  valley, 
  

   appear* 
  to 
  me, 
  save 
  so 
  far 
  as 
  they 
  may 
  be 
  due 
  to 
  the 
  rise 
  of 
  the 
  water- 
  

   line 
  in 
  consequence 
  of 
  the 
  depression 
  traced 
  in 
  Stage 
  VI. 
  , 
  to 
  have 
  accu- 
  

   mulated 
  either 
  under 
  the 
  sea, 
  or 
  in 
  estuaries 
  as 
  the 
  sea 
  was 
  invading 
  

   or 
  was 
  retiring 
  from 
  the 
  land 
  ; 
  and 
  though 
  the 
  accumulation 
  may 
  have 
  

   begun 
  as 
  the 
  valleys 
  which 
  its 
  remnants 
  occupy 
  became 
  engulphed 
  by 
  

   the 
  submergence, 
  it 
  had 
  not 
  terminated 
  at 
  the 
  time 
  represented 
  in 
  

   Map 
  2 
  and 
  its 
  continuation. 
  Inasmuch, 
  however, 
  as 
  the 
  fresh 
  water 
  

   necessarily 
  followed 
  the 
  salt 
  as 
  this 
  retired, 
  fluviatile 
  beds 
  may 
  be 
  

   present 
  in 
  these 
  valleys 
  at 
  that 
  level 
  (high 
  in 
  comparison 
  with 
  that 
  of 
  

   the 
  present 
  streams) 
  at 
  which 
  the 
  fresh 
  water 
  thus 
  following 
  was 
  at 
  

   that 
  time 
  maintained 
  by 
  the 
  retiring 
  sea, 
  without 
  indicating 
  any 
  

   great 
  excavation 
  of 
  the 
  valley 
  in 
  which 
  they 
  occur. 
  

  

  * 
  I 
  have 
  in 
  the 
  first 
  part 
  of 
  this 
  memoir 
  (p. 
  484) 
  explained 
  this 
  exceptional 
  

   occurrence 
  of 
  shells 
  in 
  the 
  gravel 
  c. 
  The 
  introduction 
  of 
  mammalian 
  remains 
  

   into 
  the 
  lower 
  part 
  of 
  the 
  Tillingbourne 
  gravel 
  from 
  the 
  destruction 
  of 
  fresh- 
  

   water 
  beds 
  of 
  antecedent 
  age, 
  as 
  the 
  sea 
  was 
  gaining 
  on 
  the 
  land 
  during 
  submer- 
  

   gence, 
  would 
  be 
  similar 
  to 
  the 
  way 
  in 
  which 
  mammalian 
  remains 
  have 
  got 
  into 
  

   the 
  Eed 
  Crag 
  ; 
  and 
  the 
  extremely 
  erroneous 
  inferences 
  which 
  have 
  from 
  such 
  

   remains 
  in 
  the 
  Crag 
  been 
  drawn 
  as 
  to 
  the 
  Mammalia 
  that 
  were 
  coeval 
  with 
  the 
  

   Bed 
  Crag 
  may, 
  toties 
  quoties, 
  apply 
  to 
  these 
  remains 
  in 
  beds 
  of 
  Glacial 
  age. 
  

   See 
  on 
  the 
  same 
  question 
  the 
  remarks 
  as 
  to 
  this 
  derivation 
  in 
  Siberia 
  made 
  in 
  

   describing 
  Stage 
  VII. 
  

  

  