﻿UPPER 
  CRETACEOUS 
  SERIES 
  (AQUEOUS). 
  41 
  

  

  Vermes. 
  

  

  27. 
  Vincularia 
  (sp. 
  D). 
  1 
  

   e. 
  28. 
  Serpula 
  plexus 
  (D). 
  1 
  

  

  Anthozoa. 
  

   e. 
  29. 
  Thamnathcea 
  decipiens 
  (D). 
  1 
  

  

  Age. 
  — 
  It 
  will 
  be 
  seen 
  that 
  out 
  of 
  twenty 
  species 
  which 
  have 
  been 
  

   determined 
  with 
  any 
  approximation, 
  seven 
  are 
  marked 
  as 
  characterising 
  

   the 
  group; 
  of 
  this 
  number, 
  three 
  are 
  equally 
  characteristic 
  of 
  the 
  

   Trichinopoly 
  beds 
  ; 
  one 
  is 
  common 
  in, 
  though 
  not 
  characteristic 
  of, 
  

   these 
  beds; 
  2 
  one 
  occurs 
  in 
  the 
  Utatur 
  group; 
  one 
  (Hemiaster 
  similis) 
  

   has 
  not 
  been 
  met 
  with 
  in 
  Southern 
  India, 
  but 
  has 
  been 
  supposed 
  

   to 
  be 
  allied 
  to 
  an 
  Arialur 
  form 
  (Hemiaster 
  rana) 
  ; 
  3 
  and 
  the 
  fourth 
  

   has 
  too 
  wide 
  a 
  range, 
  horizontally 
  as 
  well 
  as 
  vertically, 
  to 
  be 
  service- 
  

   able 
  for 
  chronological 
  purposes. 
  Of 
  the 
  thirteen 
  other 
  species, 
  five 
  

   have 
  been 
  collected 
  from 
  the 
  Arialur 
  group, 
  one 
  from 
  the 
  Trichinopoly 
  

   as 
  well, 
  two 
  from 
  this 
  group 
  only, 
  one 
  (Hemiaster 
  cenomanensis) 
  

   has 
  been 
  compared 
  to 
  an 
  Utatur 
  form 
  (Hemiaster 
  expansus)^ 
  two 
  occur 
  

   in 
  the 
  middle 
  cretaceous 
  strata 
  of 
  Europe, 
  and 
  the 
  remaining 
  two 
  are 
  of 
  

   little 
  consequence 
  for 
  homotaxy. 
  Two 
  survive 
  to 
  the 
  coralline 
  limestone, 
  

   and 
  five 
  have 
  come 
  up 
  from 
  the 
  nodular 
  limestone. 
  

  

  There 
  is 
  considerable 
  difficulty 
  in 
  exactly 
  correlating 
  the 
  Deola 
  and 
  

   Chirakhan 
  marl 
  to 
  any 
  of 
  the 
  three 
  well-defined 
  groups 
  of 
  the 
  South 
  

   Indian 
  cretaceous 
  series. 
  But 
  from 
  the 
  facts 
  just 
  set 
  forth, 
  it 
  would 
  

   not, 
  I 
  think, 
  be 
  unsafe 
  to 
  place 
  it 
  on 
  a 
  horizon 
  approximately 
  the 
  same 
  

   as 
  that 
  of 
  the 
  Trichinopoly 
  beds. 
  Had 
  not 
  Ammonites 
  guadeloupce, 
  

   Fulguraria 
  elongata, 
  and 
  Fasciolaria 
  rigida 
  (which 
  are 
  equally 
  character- 
  

   istic 
  of 
  the 
  marly 
  beds 
  under 
  consideration, 
  and 
  of 
  the 
  South 
  Indian 
  

   Trichinopoly 
  group) 
  made 
  their 
  first 
  appearance 
  in 
  the 
  nodular-limestone 
  

   sea, 
  the 
  fact 
  of 
  their 
  being 
  more 
  highly 
  organised 
  than 
  the 
  Acephalous 
  

  

  1 
  Those 
  that 
  are 
  marked 
  with 
  '* 
  D 
  " 
  have 
  been 
  taken 
  on 
  the 
  authority 
  of 
  Dr. 
  Duncan's 
  

   identification. 
  (Quart. 
  Journ., 
  GeOl. 
  Soc, 
  Vol. 
  XXI, 
  pp. 
  353, 
  &c.) 
  

   2 
  Pal. 
  Ind. 
  : 
  Tret. 
  Pelec, 
  p. 
  446. 
  

  

  8 
  Quart. 
  Journ 
  , 
  Geol. 
  Soc, 
  Vol. 
  XXI; 
  " 
  Manual," 
  p. 
  297. 
  

   * 
  Ditto 
  ditto 
  ditto. 
  

  

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  41 
  ) 
  

  

  