﻿1863.] 
  VON 
  KCEKEN 
  OLIGOCENE 
  DEPOSITS. 
  99 
  

  

  Although 
  there 
  is 
  no 
  order 
  of 
  superposition 
  to 
  be 
  seen, 
  they 
  must 
  be 
  

   divided 
  into 
  two 
  parts, 
  on 
  account 
  of 
  the 
  difference 
  in 
  the 
  fauna 
  

   of 
  the 
  different 
  beds. 
  The 
  lower 
  part 
  contains 
  a 
  large 
  number 
  of 
  

   species 
  from 
  the 
  Systeme 
  Tongrien 
  and 
  Systeme 
  Rupelien, 
  together 
  

   with 
  a 
  number 
  of 
  new 
  and 
  very 
  characteristic 
  fossils 
  — 
  large 
  Spatan- 
  

   gides 
  (Echinolampas 
  Kleinii 
  and 
  others), 
  Pecten, 
  Cyiherece, 
  &c, 
  which 
  

   pass 
  over 
  to 
  the 
  superior 
  part, 
  where 
  small 
  Nassce 
  make 
  their 
  first 
  

   appearance, 
  generally 
  in 
  large 
  numbers. 
  This 
  genus 
  does 
  not 
  exist 
  

   in 
  the 
  older 
  beds, 
  but 
  occurs 
  generally 
  in 
  the 
  rocks 
  of 
  the 
  Miocene 
  

   and 
  Pliocene 
  periods, 
  and 
  exists 
  in 
  the 
  recent 
  seas. 
  

  

  It 
  is 
  impossible 
  at 
  present 
  to 
  give 
  comparative 
  lists 
  of 
  fossils, 
  be- 
  

   cause 
  many 
  of 
  the 
  species 
  have 
  not 
  yet 
  been 
  described, 
  or, 
  if 
  de- 
  

   scribed, 
  have 
  been 
  incorrectly 
  determined 
  ; 
  but 
  no 
  geologist 
  who 
  has 
  

   studied 
  these 
  beds, 
  as 
  well 
  as 
  the 
  underlying 
  and 
  overlying 
  strata, 
  

   can 
  deny 
  that 
  they 
  form, 
  with 
  the 
  Systemes 
  Rupelien 
  and 
  Tongrien, 
  a 
  

   particular 
  group, 
  as 
  different 
  from 
  the 
  older 
  as 
  from 
  the 
  younger 
  de- 
  

   posits. 
  This 
  fact 
  has 
  been 
  fully 
  recognized 
  by 
  Professor 
  Beyrich, 
  of 
  

   Berlin, 
  who 
  proposed, 
  many 
  years 
  ago, 
  in 
  a 
  paper 
  communicated 
  to 
  

   the 
  Royal 
  Academy 
  of 
  Berlin*, 
  to 
  establish 
  for 
  this 
  group 
  the 
  name 
  

   of 
  Oligocene 
  ; 
  and 
  this 
  name 
  has 
  been 
  accepted 
  wherever 
  its 
  upper 
  

   member 
  (Cassel, 
  Osnabriick, 
  &c.) 
  is 
  "known. 
  The 
  London 
  Clay 
  and 
  

   Lower 
  London 
  Tertiaries 
  now 
  form 
  the 
  Lower 
  Eocene, 
  the 
  Brackle- 
  

   sham 
  series 
  the 
  Middle, 
  and 
  the 
  Barton 
  Clay 
  the 
  Upper 
  Eocene 
  f. 
  The 
  

   Systeme 
  Tongrien 
  inferieur 
  represents 
  the 
  Lower 
  Oligocene, 
  and 
  the 
  

   Systeme 
  Rupelien 
  the 
  Middle 
  Oligocene, 
  to 
  which 
  it 
  will 
  be 
  neces- 
  

   sary, 
  I 
  suppose, 
  to 
  join 
  the 
  Belgian 
  freshwater 
  beds 
  of 
  the 
  Systeme 
  

   Tongrien 
  superieur. 
  

  

  The 
  Lower 
  Oligocene 
  is 
  well 
  developed, 
  with 
  a 
  true 
  marine 
  fauna, 
  

   in 
  Belgium, 
  near 
  Tongres 
  (north 
  of 
  Liege), 
  and 
  in 
  the 
  North 
  of 
  

   Germany 
  between 
  Magdeburg, 
  Bernburg, 
  Aschersleben, 
  Egeln, 
  and 
  

   Helmstadt 
  (near 
  Brunswick 
  %), 
  and 
  it 
  contains 
  above 
  700 
  species 
  of 
  

   Mollusca, 
  besides 
  a 
  large 
  number 
  of 
  Corals, 
  Bryozoa, 
  and 
  Forami- 
  

   nifera, 
  and 
  several 
  species 
  of 
  Fish-teeth 
  and 
  Echinodermata 
  ; 
  and 
  

   the 
  most 
  characteristic 
  of 
  these 
  fossils 
  have 
  also 
  been 
  found 
  at 
  

   Brockenhurst. 
  The 
  fossils 
  from 
  this 
  locality 
  contained 
  in 
  Mr. 
  Ed- 
  

   wards's 
  cabinet 
  are 
  the 
  following 
  (the 
  asterisks 
  in 
  the 
  different 
  

   columns 
  signify 
  the 
  presence 
  of 
  the 
  different 
  species 
  in 
  the 
  respective 
  

   beds) 
  : 
  — 
  

  

  * 
  " 
  Ueber 
  den 
  Zusammenhang 
  der 
  norddeutschen 
  Tertiarbildungen, 
  zur 
  Er- 
  

   laiiterung 
  einer 
  geologische 
  Uebersichtskarte." 
  Abhandl. 
  der 
  K. 
  Akad. 
  der 
  Wis- 
  

   senschaften 
  zu 
  Berlin. 
  Aus 
  dem 
  Jahrel855, 
  p. 
  1. 
  

  

  t 
  The 
  White 
  Griasshouse-sand 
  also 
  belongs 
  to 
  this 
  last 
  division, 
  because, 
  at 
  

   Hordwell, 
  it 
  contains 
  many 
  characteristic 
  Barton 
  fossils 
  — 
  Oliva 
  Branderi, 
  &c. 
  

  

  \ 
  As 
  these 
  fossiliferous 
  beds 
  (about 
  10 
  feet 
  in 
  thickness) 
  are 
  covered 
  with 
  beds 
  

   of 
  gravel 
  and 
  sand, 
  sometimes 
  more 
  than 
  200 
  feet 
  thick, 
  and 
  containing 
  much 
  

   water, 
  it 
  is 
  impossible 
  to 
  dig 
  pits 
  for 
  the 
  mere 
  purpose 
  of 
  obtaining 
  the 
  fossils. 
  

   But 
  below 
  these 
  beds 
  there 
  are 
  seams 
  of 
  fossil 
  wood, 
  upwards 
  of 
  150 
  feet 
  in 
  

   thickness, 
  which 
  are 
  worked 
  by 
  numerous 
  mines, 
  and 
  to 
  this 
  circumstance 
  we 
  

   are 
  indebted 
  for 
  obtaining 
  the 
  fossils, 
  winch 
  are 
  found 
  in 
  a 
  tolerable 
  state 
  of 
  

   preservation 
  only 
  at 
  the 
  different 
  mining-works 
  which 
  pass 
  through 
  the 
  fossili- 
  

   ferous 
  beds. 
  

  

  h2 
  

  

  