﻿REJTEVIER 
  VAUDOIS 
  ALPS. 
  27 
  

  

  analogy 
  exists, 
  as 
  might 
  have 
  been 
  expected, 
  with 
  the 
  Alpine 
  de- 
  

   posits, 
  and 
  especially 
  with 
  those 
  on 
  the 
  northern 
  flank 
  of 
  the 
  chain. 
  

   53 
  per 
  cent, 
  of 
  my 
  species 
  are 
  found 
  in 
  the 
  Infralias 
  of 
  Lombardy, 
  

   and 
  62 
  per 
  cent, 
  in 
  the 
  Upper 
  Keuper 
  or 
  Ivossen 
  beds 
  of 
  the 
  Eastern 
  

   Alps, 
  whereas 
  the 
  species 
  quoted 
  in 
  the 
  extra- 
  Alpine 
  formations 
  are 
  

   only 
  nine 
  for 
  each 
  bed, 
  or 
  26 
  per 
  cent, 
  only." 
  

  

  " 
  Independence 
  of 
  the 
  two 
  Faunas. 
  — 
  I 
  have 
  only 
  found 
  in 
  our 
  Alps 
  

   one 
  species 
  common 
  to 
  the 
  Upper 
  and 
  Lower 
  zone, 
  Placunopsis 
  Schaf- 
  

   hautli. 
  With 
  regard 
  to 
  other 
  districts, 
  however, 
  the 
  connexion 
  between 
  

   the 
  two 
  formations 
  is 
  greater. 
  Pecten 
  Valoniensis 
  and 
  P. 
  Lugdunensis 
  

   of 
  the 
  lower 
  zone 
  appear 
  in 
  the 
  Lyonnais 
  to 
  belong 
  to 
  the 
  Infralias. 
  

   Mytilus 
  semicircularis 
  of 
  the 
  upper 
  zone 
  is 
  said 
  to 
  occur 
  in 
  Lom- 
  

   bardy, 
  in 
  the 
  Avicida-contorta 
  bed 
  ; 
  and 
  Spondylus 
  liasinus 
  of 
  the 
  

   upper 
  zone 
  is 
  probably 
  the 
  same 
  as 
  Plicatula 
  interstriata 
  of 
  the 
  

   Avicida-contorta 
  zone. 
  Admitting 
  these 
  identifications 
  to 
  be 
  correct, 
  

   there 
  would 
  at 
  the 
  outside 
  be 
  only 
  10 
  per 
  cent, 
  of 
  the 
  species 
  com- 
  

   mon 
  to 
  the 
  two 
  faunas, 
  whereas 
  at 
  least 
  13 
  per 
  cent, 
  of 
  the 
  species 
  of 
  

   the 
  upper 
  zone 
  pass 
  upwards 
  into 
  the 
  Gryphaea-limestone. 
  My 
  two 
  

   zones 
  are 
  therefore 
  at 
  least 
  as 
  independent 
  one 
  of 
  the 
  other 
  as 
  the 
  

   Infralias 
  can 
  be 
  of 
  the 
  Sinemurien." 
  

  

  " 
  This 
  independence 
  is 
  fully 
  admitted 
  by 
  those 
  geologists 
  who, 
  like 
  

   MM. 
  Oppel, 
  Giimbel, 
  Winkler, 
  Wright, 
  and 
  Moore, 
  place 
  the 
  In- 
  

   fralias 
  (the 
  zone 
  of 
  Ammonites 
  planorbis 
  and 
  A. 
  angulatus) 
  in 
  the 
  

   Lias, 
  and 
  the 
  Avicida-contorta 
  zone 
  in 
  the 
  Trias. 
  But 
  others, 
  as 
  

   MM. 
  D'Archiac, 
  Hebert, 
  Martin, 
  and 
  Stoppani, 
  consider 
  these 
  two 
  

   geological 
  horizons 
  merely 
  as 
  subdivisions 
  of 
  the 
  same 
  formation 
  — 
  

   the 
  Infralias 
  orEtage 
  Infraliasien 
  (Stopp.), 
  which 
  they 
  look 
  upon 
  as 
  

   the 
  lower 
  division 
  of 
  the 
  Lias. 
  Both 
  the 
  geological 
  and 
  palaeontolo- 
  

   gical 
  facts 
  observed 
  in 
  our 
  Alps 
  are, 
  however, 
  contrary 
  to 
  such 
  an 
  

   approximation, 
  and 
  lead 
  me 
  to 
  consider 
  these 
  two 
  fossiliferous 
  zones 
  

   as 
  two 
  distinct 
  formations, 
  as 
  much 
  as 
  the 
  Keuperien, 
  Sinemurien, 
  

   Liasien, 
  &c." 
  

  

  The 
  author 
  then 
  proceeds 
  to 
  criticise 
  what 
  he 
  considers 
  the 
  undue 
  

   extension 
  of 
  the 
  term 
  Infralias 
  to 
  the 
  Avicida-contorta 
  beds. 
  When 
  

   originally 
  introduced 
  by 
  M. 
  Leymerie, 
  it 
  was 
  confined 
  to 
  those 
  upper 
  

   beds 
  which 
  are 
  the 
  equivalents 
  of 
  the 
  author's 
  upper 
  zone, 
  and 
  he 
  

   further 
  thinks 
  that 
  to 
  apply 
  the 
  term 
  Infralias 
  to 
  the 
  Avicula- 
  

   contorta 
  beds, 
  as 
  well 
  as 
  to 
  those 
  containing 
  the 
  Ammonites 
  planor- 
  

   bis 
  and 
  A. 
  angulatus, 
  is 
  to 
  prejudge 
  the 
  controverted 
  question 
  as 
  to 
  

   whether 
  the 
  Avicula-contorta 
  beds 
  belong 
  to 
  the 
  Trias 
  or 
  the 
  Lias. 
  

   He 
  proposes 
  that 
  the 
  term 
  should 
  be 
  rejected 
  altogether, 
  and 
  that 
  

   the 
  upper 
  zone 
  should 
  be 
  called 
  the 
  Etage 
  Hettangien, 
  and 
  that 
  the 
  

   Avicula-contorta 
  beds 
  should 
  be 
  called 
  the 
  Etage 
  Rhaetien. 
  This 
  

   term, 
  proposed 
  by 
  M. 
  Giimbel, 
  and 
  adopted 
  in 
  England 
  by 
  MM. 
  

   Moore, 
  Rupert 
  Jones, 
  &c, 
  and 
  also, 
  as 
  it 
  appears, 
  in 
  Austria 
  by 
  M. 
  

   Suess, 
  has 
  the 
  great 
  advantage 
  that 
  it 
  can 
  be 
  adopted 
  by 
  all 
  geolo- 
  

   gists, 
  whatever 
  may 
  be 
  their 
  opinion 
  respecting 
  the 
  controverted 
  

   question. 
  

  

  After 
  mentioning 
  the 
  different 
  geologists 
  who 
  have 
  advocated 
  the 
  

   Triassic 
  or 
  Liassic 
  theory 
  for 
  the 
  Avicula-contorta 
  beds, 
  the 
  author 
  con- 
  

  

  VOL. 
  XX.— 
  PART 
  II. 
  F 
  

  

  