﻿middle 
  pleistocene 
  gkavel 
  in 
  lancashire. 
  41 
  

  

  Discussion. 
  

  

  Mr. 
  Darbishtre 
  was 
  not 
  prepared 
  to 
  accept 
  the 
  view 
  of 
  the 
  shells 
  

   in 
  the 
  Drift 
  having 
  existed 
  on 
  the 
  spots 
  where 
  now 
  found. 
  He 
  

   thought 
  rather 
  that 
  the 
  fragmentary 
  remains 
  might 
  have 
  been 
  de- 
  

   rived 
  from 
  the 
  destruction 
  of 
  earlier 
  beds 
  deposited 
  under 
  somewhat 
  

   different 
  conditions. 
  The 
  occurrence 
  at 
  Wexford 
  of 
  nearly 
  similar 
  

   beds 
  to 
  those 
  at 
  Leyland 
  pointed 
  to 
  a 
  great 
  destruction 
  of 
  an 
  old 
  

   sea-shore. 
  

  

  Mr. 
  Gwtn 
  Jeffreys 
  thought 
  that 
  all 
  the 
  shells 
  found 
  in 
  these 
  

   Lancashire 
  beds 
  were 
  just 
  such 
  as 
  might 
  have 
  been 
  thrown 
  up 
  on 
  

   the 
  shore, 
  though 
  the 
  matrix 
  in 
  which 
  some 
  of 
  them 
  are 
  found 
  is 
  

   not 
  sandy. 
  The 
  Trophon 
  discovered 
  was 
  T. 
  truncatus, 
  and 
  not 
  

   T. 
  clathratus. 
  Neither 
  was 
  he 
  quite 
  satisfied 
  that 
  Miss 
  Ffarington's 
  

   Fusus 
  (or 
  rather 
  Trophon) 
  was 
  really 
  T. 
  cratiadatus. 
  The 
  occurrence 
  

   of 
  Fusus 
  antiquus, 
  monstr. 
  contrarius, 
  did 
  not 
  surprise 
  him, 
  though 
  

   that 
  of 
  Mactra 
  glauca 
  was 
  very 
  remarkable. 
  He 
  did 
  not 
  believe 
  in 
  

   the 
  retiring 
  or 
  voluntary 
  migration 
  of 
  Mollusca, 
  though 
  they 
  might 
  be 
  

   transported 
  by 
  currents 
  or 
  driven 
  away 
  by 
  want 
  of 
  food. 
  He 
  did 
  

   not 
  regard 
  any 
  of 
  the 
  shells 
  as 
  truly 
  Arctic, 
  and 
  doubted 
  whether 
  

   any 
  of 
  them 
  afforded 
  clear 
  evidence 
  of 
  climatal 
  conditions. 
  

  

  Mr. 
  Prestwich 
  remarked 
  on 
  the 
  progress 
  which 
  had 
  been 
  made 
  

   in 
  our 
  knowledge 
  of 
  these 
  shells 
  since 
  Sir 
  P. 
  Egerton 
  had 
  first 
  called 
  

   attention 
  to 
  the 
  Drift 
  in 
  which 
  they 
  occur. 
  The 
  number 
  of 
  perfect 
  

   specimens 
  from 
  Leyland 
  was, 
  he 
  thought, 
  very 
  striking. 
  He 
  had 
  

   some 
  difficulty 
  in 
  following 
  Mr. 
  Beade 
  into 
  the 
  large 
  theoretical 
  

   questions 
  into 
  which 
  he 
  had 
  entered, 
  but 
  pointed 
  out 
  that 
  the 
  stria- 
  

   tion 
  of 
  the 
  surface 
  of 
  the 
  country 
  was 
  significant 
  of 
  a 
  period 
  of 
  

   intense 
  cold, 
  which 
  any 
  alteration 
  in 
  the 
  arrangement 
  and 
  pro- 
  

   portions 
  of 
  land 
  and 
  water 
  could 
  hardly 
  account. 
  But 
  in 
  the 
  over- 
  

   lying 
  Boulder-clay 
  the 
  fragments 
  of 
  shells 
  were 
  all 
  of 
  species 
  still 
  

   existing 
  in 
  the 
  neighbouring 
  seas 
  of 
  the 
  present 
  day 
  ; 
  and 
  he 
  did 
  

   not 
  think 
  that 
  at 
  the 
  time 
  of 
  its 
  deposit 
  the 
  climate 
  was 
  of 
  necessity 
  

   intensely 
  cold. 
  

  

  Prof. 
  Hughes 
  did 
  not 
  think 
  that 
  the 
  deposits 
  were 
  in 
  any 
  way 
  

   immediately 
  connected 
  with 
  the 
  Boulder- 
  clay, 
  to 
  which 
  they 
  were 
  

   long 
  subsequent. 
  He 
  rather 
  correlated 
  them 
  with 
  the 
  Hessle 
  and 
  

   Kelsey 
  beds 
  of 
  the 
  east 
  coast. 
  The 
  deposits 
  might 
  in 
  many 
  cases 
  

   have 
  been 
  formed 
  on 
  the 
  shore 
  of 
  a 
  sea 
  which 
  was 
  eroding 
  a 
  cliff 
  of 
  

   Boulder-clay 
  ; 
  and 
  by 
  this 
  means 
  there 
  would 
  be 
  an 
  admixture 
  of 
  

   the 
  more 
  recent 
  shells 
  with 
  the 
  redeposited 
  boulders 
  from 
  the 
  older 
  

   clay. 
  He 
  submitted 
  that 
  the 
  shells 
  belonged 
  to 
  an 
  age 
  succeeding 
  

   the 
  true 
  Glacial 
  period. 
  In 
  the 
  higher 
  deposits 
  there 
  were 
  still 
  some 
  

   traces 
  of 
  the 
  more 
  Arctic 
  forms, 
  while 
  a 
  more 
  southern 
  facies 
  came 
  

   over 
  the 
  fauna 
  of 
  the 
  lower 
  beds. 
  

  

  Mr. 
  Charlesworth 
  observed 
  on 
  the 
  possibility 
  of 
  the 
  transport 
  of 
  

   shells 
  in 
  the 
  stomachs 
  of 
  fishes. 
  As 
  to 
  the 
  comminuted 
  condition 
  of 
  

   Cyprina 
  islandica, 
  he 
  remarked 
  that 
  in 
  the 
  Crag 
  beds 
  these 
  shells 
  

   are 
  nearly 
  always 
  much 
  cracked, 
  even 
  when 
  delicate 
  shells 
  in 
  the 
  

   neighbourhood 
  are 
  perfect. 
  

  

  