﻿204 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  [Mar. 
  9, 
  

  

  of 
  a 
  considerable 
  gap 
  in 
  the 
  same 
  parts 
  of 
  Europe. 
  In 
  France 
  it 
  

   covers 
  Neocomian 
  at 
  Orgon, 
  there 
  being 
  six 
  of 
  D'Orbigny's 
  stages 
  

   missing. 
  At 
  Aude 
  it 
  is 
  placed 
  on 
  Palaeozoic 
  rocks, 
  and 
  in 
  the 
  De- 
  

   partment 
  of 
  the 
  Var 
  it 
  is 
  on 
  Jurassic. 
  In 
  Brittany 
  it 
  overspreads 
  

   successively 
  Cretaceous, 
  Jurassic, 
  Palaeozoic, 
  and 
  Azoic 
  rocks. 
  Mr. 
  

   Hamilton 
  (our 
  present 
  President), 
  in 
  one 
  of 
  his 
  addresses*, 
  de- 
  

   riving 
  his 
  information 
  from 
  Captain 
  Grant 
  and 
  others, 
  informs 
  us 
  

   that 
  wide 
  expanses 
  in 
  India, 
  namely, 
  in 
  Scinde, 
  Cutch, 
  Beloochistan, 
  

   and 
  the 
  Punjaub, 
  are 
  covered 
  with 
  Nummulitic 
  Limestone 
  capping 
  

   arenaceous 
  and 
  clayey 
  strata, 
  which 
  he, 
  not 
  on 
  Cretaceous, 
  but 
  on 
  

   Jurassic 
  or 
  some 
  still 
  older 
  bed. 
  

  

  On 
  the 
  Upper 
  Missouri, 
  Dr. 
  Hayden 
  f, 
  in 
  1861, 
  described 
  Eocene 
  

   strata 
  lying 
  first 
  upon 
  some 
  thin 
  Cretaceous 
  and 
  Jurassic 
  beds, 
  and 
  

   then 
  on 
  Primordial 
  sandstone, 
  supported 
  unconformably 
  by 
  Lauren- 
  

   tian 
  gneiss 
  and 
  granite. 
  Here, 
  therefore, 
  the 
  gaps 
  are 
  many 
  and 
  

   very 
  great. 
  

  

  Nummulite 
  Limestone 
  rests, 
  near 
  Thun, 
  on 
  NeocomianJ, 
  and 
  in 
  

   the 
  Diablerets 
  on 
  Gault, 
  the 
  fossils 
  of 
  the 
  two 
  formations 
  being 
  

   sometimes 
  mingled 
  together. 
  

  

  3. 
  With 
  a 
  Cretaceous 
  Hoof. 
  — 
  Premising 
  a 
  few 
  words 
  on 
  the 
  mem- 
  

   bers 
  of 
  this 
  formation, 
  I 
  may 
  observe 
  that 
  a 
  valuable 
  table, 
  drawn 
  

   up 
  by 
  Vicomte 
  d'Archiac, 
  and 
  referring 
  to 
  seventy-one 
  different 
  re- 
  

   gions, 
  both 
  small 
  and 
  large, 
  enables 
  me 
  to 
  state 
  that, 
  massing 
  together 
  

   all 
  the 
  subdivisions 
  of 
  the 
  Cretaceous 
  series, 
  little 
  more 
  than 
  one- 
  

   third 
  of 
  the 
  whole 
  has 
  been 
  actually 
  laid 
  down 
  in 
  these 
  seventy-one 
  

   countries. 
  They 
  are 
  found 
  in 
  twos 
  and 
  threes 
  ; 
  and 
  it 
  is 
  exceed- 
  

   ingly 
  rare 
  to 
  find 
  the 
  whole, 
  or 
  nearly 
  the 
  whole, 
  succession 
  in 
  one 
  

   place. 
  Gaps, 
  therefore, 
  among 
  the 
  members 
  of 
  the 
  chalk-beds, 
  im- 
  

   plying 
  subaerial 
  conditions, 
  are 
  all 
  but 
  universal 
  in 
  space 
  and 
  time 
  ; 
  

   and 
  this 
  is 
  the 
  case 
  also 
  in 
  other 
  portions 
  of 
  the 
  sedimentary 
  series. 
  

   We 
  see 
  from 
  this 
  elaborate 
  table 
  § 
  that 
  of 
  our 
  four 
  Cretaceous 
  

   groups, 
  1, 
  White 
  Chalk 
  ; 
  2, 
  Chalk-marl 
  and 
  Upper 
  Greensand 
  ; 
  3, 
  

   Gault 
  ; 
  4, 
  Neocomian, 
  the 
  most 
  constant 
  is 
  the 
  second, 
  for 
  it 
  occurs 
  

   in 
  65 
  regions 
  out 
  of 
  71 
  ; 
  then 
  comes 
  the 
  first, 
  found 
  in 
  38 
  regions 
  ; 
  

   the 
  fourth 
  in 
  32 
  ; 
  and 
  the 
  third 
  only 
  in 
  13 
  regions. 
  

  

  As 
  to 
  their 
  thickness, 
  and 
  the 
  lapse 
  of 
  time 
  represented, 
  they 
  are 
  

   in 
  the 
  following 
  order 
  : 
  — 
  the 
  fourth 
  group 
  is 
  the 
  thickest 
  ; 
  then 
  the 
  

   second, 
  first, 
  and 
  third 
  successively. 
  

  

  The 
  series 
  is 
  most 
  complete 
  in 
  England 
  and 
  France 
  ; 
  next 
  follow 
  

   the 
  north 
  of 
  Germany, 
  and 
  the 
  province 
  of 
  Constantine 
  in 
  Algeria. 
  

  

  The 
  south 
  flank 
  of 
  the 
  Maritime 
  Alps 
  and 
  the 
  north 
  flank 
  of 
  

   some 
  of 
  the 
  other 
  of 
  those 
  high 
  ranges 
  present, 
  each, 
  six 
  subdivisions 
  

   of 
  Cretaceous 
  rocks 
  (13 
  in 
  the 
  whole 
  series, 
  D'Archiac) 
  ; 
  but 
  elsewhere 
  

   over 
  the 
  surface 
  of 
  the 
  globe, 
  as 
  far 
  as 
  is 
  known, 
  this 
  formation 
  may 
  

   be 
  described 
  as 
  poorly, 
  or 
  very 
  poorly, 
  represented, 
  or 
  quite 
  absent 
  ; 
  

   although 
  in 
  some 
  parts, 
  as 
  in 
  North 
  America, 
  its 
  superficial 
  extent 
  is 
  

  

  * 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  x. 
  p. 
  1. 
  

  

  t 
  Annals 
  of 
  Nat. 
  Hisi, 
  3rd 
  series, 
  vol. 
  xi. 
  p. 
  371. 
  

  

  | 
  D'Archiac, 
  ' 
  Histoire 
  des 
  Progres,' 
  vol. 
  iii. 
  pp. 
  87, 
  89. 
  

  

  § 
  ' 
  Histoire 
  des 
  Progres,' 
  vol. 
  v. 
  p. 
  610 
  bis. 
  

  

  