﻿102 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  [Dec. 
  2, 
  

  

  fewyears 
  since 
  byMr.Weinkauff*; 
  and 
  Professor 
  San 
  dberger 
  considers 
  

   the 
  marine 
  sand 
  of 
  Weinheim, 
  &c, 
  as 
  the 
  lower 
  part, 
  and 
  the 
  " 
  clay 
  

   with 
  Septaria 
  " 
  as 
  the 
  npper 
  part, 
  of 
  the 
  Middle 
  Oligocene, 
  inclu- 
  

   ding 
  all 
  the 
  freshwater 
  beds 
  in 
  the 
  Upper 
  Oligocene. 
  The 
  marine 
  

   sand 
  of 
  Weinheim 
  he 
  identifies 
  with 
  the 
  " 
  Sables 
  de 
  Eontainebleau 
  " 
  

   and 
  some 
  sandy 
  beds 
  at 
  Neustadt 
  -Magdeburg, 
  and 
  also 
  with 
  the 
  

   upper 
  (marine) 
  beds 
  of 
  the 
  Hempstead 
  series. 
  Now 
  the 
  fauna 
  of 
  

   the 
  Neustadt- 
  Magdeburg 
  and 
  Weinheim 
  beds 
  is 
  somewhat 
  different 
  

   from 
  that 
  of 
  the 
  real 
  " 
  clay 
  with 
  Septaria 
  " 
  described 
  by 
  several 
  

   authors, 
  but 
  in 
  certain 
  localities 
  in 
  the 
  North 
  of 
  Germany, 
  for 
  instance 
  

   near 
  Sollingen 
  (near 
  Brunswick), 
  beds 
  with 
  the 
  same 
  fauna 
  as 
  those 
  

   near 
  Magdeburg 
  are 
  seen 
  in 
  superposition 
  to 
  the 
  clay 
  with 
  Leda 
  

   Deshayesii. 
  We 
  are 
  obliged, 
  therefore, 
  to 
  consider 
  the 
  difference 
  of 
  

   these 
  two 
  faunas 
  as 
  caused 
  only 
  by 
  a 
  difference 
  of 
  conditions 
  at 
  the 
  

   localities, 
  — 
  difference 
  in 
  the 
  depth 
  of 
  the 
  sea, 
  &c, 
  indicated 
  too 
  by 
  

   the 
  difference 
  of 
  the 
  lithological 
  structure, 
  — 
  and 
  for 
  this 
  reason 
  we 
  

   cannot 
  divide, 
  generally, 
  the 
  Middle 
  Oligocene 
  into 
  two 
  periods. 
  

  

  Mr. 
  Edwards, 
  whose 
  complete 
  knowledge 
  of 
  the 
  English 
  Ter- 
  

   tiaries 
  abundantly 
  qualifies 
  him 
  for 
  the 
  task, 
  intends 
  working 
  out 
  

   the 
  identity 
  of 
  the 
  Mayence 
  and 
  Belgian 
  freshwater 
  fossils 
  with 
  

   those 
  of 
  the 
  Isle 
  of 
  Wight, 
  and 
  I 
  have 
  no 
  doubt 
  that 
  he 
  will 
  find, 
  

   besides 
  the 
  great 
  number 
  already 
  considered 
  identical, 
  a 
  still 
  greater 
  

   number 
  common 
  to 
  the 
  three 
  localities. 
  The 
  freshwater 
  beds 
  of 
  the 
  

   Mayence 
  Basin 
  and 
  of 
  Belgium 
  will 
  therefore 
  probably 
  form 
  part 
  of 
  

   the 
  Middle 
  Oligocene, 
  as 
  well 
  as 
  all 
  the 
  Hempstead 
  series. 
  It 
  will 
  

   be 
  decided 
  only 
  then, 
  where 
  we 
  are 
  to 
  place 
  the 
  Bembridge 
  series 
  

   and, 
  with 
  it, 
  the 
  Paris 
  freshwater 
  beds, 
  which 
  until 
  now 
  have 
  been 
  

   considered 
  to 
  belong 
  to 
  the 
  Lower 
  Oligocene. 
  

  

  One 
  of 
  the 
  best 
  reasons 
  for 
  accepting 
  Professor 
  Beyrich's 
  " 
  Oligo- 
  

   cene" 
  is, 
  I 
  think, 
  that 
  between 
  each 
  of 
  his 
  four 
  periods 
  there 
  appear 
  

   to 
  have 
  been 
  great 
  general 
  changes 
  over 
  all 
  Europe. 
  The 
  marine 
  

   beds 
  of 
  the 
  Eocene 
  period 
  in 
  Erance 
  and 
  England 
  are 
  mostly 
  suc- 
  

   ceeded 
  by 
  freshwater 
  beds 
  ; 
  sometimes 
  the 
  Oligocene 
  beds 
  do 
  not 
  

   exist 
  at 
  all, 
  whereas 
  they 
  are 
  the 
  lowest 
  Tertiary 
  strata 
  over 
  all 
  

   Germany, 
  from 
  Brunswick 
  to 
  Konigsbergt. 
  Miocene 
  formations 
  

   do 
  not 
  exist 
  in 
  England 
  and 
  in 
  the 
  North 
  of 
  Erance 
  ; 
  in 
  Belgium 
  X 
  

   and 
  in 
  Northern 
  Germany 
  they 
  occur 
  very 
  near 
  the 
  coast 
  ; 
  but, 
  

   on 
  the 
  other 
  hand, 
  beds 
  of 
  this 
  age 
  are 
  very 
  much 
  developed 
  in 
  

   Poland, 
  Hungary, 
  Southern 
  Germany, 
  and 
  the 
  South 
  of 
  Erance, 
  

   where 
  the 
  Oligocene 
  is 
  wanting. 
  The 
  Pliocene, 
  again, 
  is 
  wanting 
  

   in 
  the 
  last-named 
  countries 
  and 
  in 
  the 
  North 
  of 
  Germany, 
  while 
  it 
  

   skirts 
  the 
  coast 
  in 
  Belgium 
  and 
  Erance, 
  and 
  occurs 
  also 
  in 
  England. 
  

  

  * 
  See 
  his 
  paper 
  " 
  Septarien-Thon 
  im 
  Mainzer 
  Becken." 
  Neues 
  Jahrb. 
  1860, 
  

   p. 
  177 
  ; 
  also 
  " 
  Ueber 
  die 
  tertiaren 
  Ablagerungen 
  im 
  Kreise 
  Kreuznach." 
  Zeit- 
  

   schrift 
  der 
  nat.-hist. 
  Vereins 
  der 
  Preuss. 
  Rheinlande 
  und 
  Westphalens. 
  Jahrg. 
  

   xvi., 
  p. 
  65. 
  

  

  t 
  Prof. 
  Beyrich 
  considers 
  certain 
  beds 
  near 
  Konigsberg 
  to 
  be 
  Lower 
  Oligocene. 
  

  

  X 
  About 
  a 
  twelvemonth 
  ago 
  I 
  identified 
  the 
  Systeme 
  Diestien 
  of 
  M. 
  Dumont 
  

   with 
  the 
  Miocene 
  of 
  the 
  North 
  of 
  Germany. 
  Typical 
  species 
  from 
  the 
  Superga 
  

   near 
  Turin, 
  as 
  Oliva 
  Dufresnei, 
  Bast., 
  Nassa 
  flexuosa, 
  Brocchi, 
  &c, 
  exist 
  there. 
  

   The 
  Systeme 
  Bolderien 
  is 
  also 
  identical 
  with 
  the 
  Systeme 
  Diestien. 
  

  

  