﻿i92 
  proceedings 
  of 
  the 
  geological 
  society. 
  

  

  § 
  6. 
  Great 
  Oolite. 
  

  

  Plantje. 
  — 
  20 
  genera 
  and 
  35 
  species 
  are 
  distributed 
  through 
  the 
  

   Great 
  Oolite. 
  The 
  flora 
  of 
  the 
  Inferior 
  Oolite 
  we 
  determined 
  to 
  be 
  

   41 
  genera 
  and 
  130 
  species, 
  or 
  nearly 
  four 
  times 
  as 
  prolific 
  : 
  and, 
  be 
  

   it 
  remembered, 
  there 
  is 
  not 
  a 
  species 
  iu 
  common 
  between 
  the 
  two 
  

   formations, 
  unless 
  Tliuytes 
  expansus 
  should 
  prove 
  to 
  be 
  so. 
  Thus 
  

   the 
  Lower 
  Oolites 
  possess 
  165 
  species, 
  none 
  of 
  which 
  pass 
  to 
  any 
  

   higher 
  horizon 
  ; 
  and, 
  with 
  the 
  addition 
  of 
  Cycadeostrobus 
  splicericus 
  

   in 
  the 
  Oxford 
  Clay, 
  4 
  genera 
  and 
  7 
  species 
  in 
  the 
  Coral 
  Rag, 
  and 
  

   PJdebopteris 
  depressus 
  and 
  Pinites 
  depressus 
  in 
  the 
  Kimmeridge, 
  

   we 
  have 
  the 
  entire 
  flora 
  of 
  the 
  Oolitic 
  rocks 
  ; 
  adding 
  the 
  17 
  species 
  

   known 
  in 
  the 
  Lias, 
  the 
  whole 
  Jurassic 
  flora 
  comprises 
  63 
  genera 
  

   and 
  191 
  species. 
  Araucarites 
  Brodiei, 
  Aroides 
  Stuttered, 
  Kaidacar- 
  

   pum 
  ooliticum, 
  and 
  StricMandinia 
  acuminata 
  arc 
  amongst 
  the 
  rarer 
  

   forms 
  occurring 
  ; 
  Palceozamia 
  and 
  Tliuytes 
  contain 
  most 
  species 
  ; 
  but 
  

   none 
  of 
  the 
  genera 
  are 
  largely 
  represented. 
  Specifically 
  no 
  two 
  for- 
  

   mations, 
  so 
  closely 
  allied 
  through 
  their 
  faunas, 
  could 
  be 
  more 
  distinct 
  

   through 
  their 
  floras 
  than 
  the 
  Inferior 
  and 
  Great 
  Oolite. 
  No 
  species 
  

   passes 
  to 
  cither 
  the 
  Forest 
  Marble, 
  Cornbrash, 
  or 
  Kellaways 
  Rock, 
  

   &c, 
  &c. 
  

  

  A:\10RrnozoA 
  (Spongida). 
  — 
  Of 
  the 
  5 
  genera 
  and 
  11 
  species 
  known 
  in 
  

   all 
  the 
  Jurassic 
  rocks, 
  4 
  genera 
  and 
  9 
  species 
  occur 
  in 
  the 
  Great 
  

   Oolite 
  — 
  Manon 
  1 
  species, 
  Scyphia 
  2, 
  Spongia 
  5, 
  and 
  Talpina 
  1. 
  

   Sponyia 
  florlceps 
  appears 
  again 
  in 
  the 
  Corallian 
  beds. 
  The 
  Lias 
  

   form 
  is 
  Graatia 
  antiqua. 
  

  

  UuizoroDA. 
  — 
  None. 
  

  

  Ccelexterata. 
  — 
  15 
  genera 
  and 
  38 
  species 
  have 
  been 
  described 
  

   from 
  the 
  Great 
  Oolite 
  ; 
  most 
  of 
  these 
  are 
  from 
  the 
  Cotteswolds, 
  

   although 
  Northamptonshire 
  and 
  Lincolnshire 
  have 
  contributed 
  to 
  

   the 
  large 
  number 
  of 
  species. 
  No 
  higher 
  horizon 
  approaches 
  this 
  in 
  

   number 
  or 
  variety 
  ; 
  none 
  appear 
  in 
  the 
  Kellaways 
  Rock 
  or 
  Oxford 
  

   Clay 
  (or 
  in 
  the 
  Oxfordian 
  rocks). 
  The 
  group 
  culminates 
  in 
  the 
  Corallian 
  

   beds, 
  though 
  the 
  number 
  of 
  species 
  is 
  small 
  compared 
  with 
  those 
  of 
  the 
  

   Great 
  and 
  Inferior 
  Oolites. 
  Cyathophora, 
  Isastrcea, 
  and 
  Thamnastrcea 
  

   are 
  the 
  only 
  genera 
  largely 
  represented; 
  the 
  home 
  for 
  Montlivaltia, 
  

   with 
  its 
  39 
  species, 
  is 
  the 
  Lower 
  Lias 
  (21) 
  and 
  the 
  Inferior 
  Oolite 
  

   (11) 
  ; 
  the 
  remaining 
  7 
  species 
  spread 
  through 
  the 
  Great 
  Oolite 
  (3), 
  

   Forest 
  Marble 
  (3), 
  and 
  the 
  Coral 
  Rag 
  (1). 
  The 
  researches 
  of 
  Dr. 
  

   Duncan 
  into 
  the 
  Coelenterate 
  fauna 
  of 
  the 
  Jurassic 
  rocks 
  have 
  greatly 
  

   added 
  to 
  our 
  intimate 
  acquaintance 
  with 
  this 
  intricate 
  and 
  interest- 
  

   ing 
  group. 
  

  

  Echixodermata. 
  —The 
  whole 
  group 
  in 
  the 
  Great 
  Oolite 
  numbers 
  

   22 
  genera 
  and 
  53 
  species, 
  nearly 
  as 
  in 
  the 
  Inferior 
  Oolite. 
  I 
  will 
  

   analyze 
  the 
  groups 
  separately, 
  as 
  they 
  are 
  of 
  much 
  importance 
  to 
  the 
  

   strati 
  graphical 
  geologist. 
  Next 
  to 
  the 
  Ammonites 
  in 
  importance, 
  

   they 
  have 
  received 
  much 
  attention 
  at 
  the 
  hands 
  of 
  French 
  and 
  

   German 
  palaeontologists, 
  especially 
  the 
  former. 
  They 
  fall 
  under 
  four 
  

   sections 
  or 
  groups, 
  the 
  Ecliinoidea 
  (in 
  two 
  sections), 
  the 
  Asteroidea 
  

   and 
  the 
  Crinoidea. 
  

  

  Ecliinoidea 
  Eadocyclica. 
  — 
  8 
  genera 
  and 
  27 
  species 
  belong 
  to 
  this 
  

   beautiful 
  group 
  in 
  the 
  Great 
  Oolite 
  : 
  — 
  

  

  