﻿ANNIVERSARY 
  ADDRESS 
  OF 
  THE 
  PRESIDENT. 
  201 
  

  

  alpina. 
  One 
  species, 
  Acrosalenia 
  spinosa, 
  passes 
  to 
  the 
  Cornbrash 
  ; 
  

   and 
  I 
  know 
  of 
  no 
  other 
  species 
  common 
  to 
  the 
  two 
  horizons. 
  

  

  Annelida. 
  — 
  Serpula 
  intestinalis 
  is 
  the 
  only 
  species 
  occurring 
  in 
  

   the 
  Forest 
  Marble, 
  and 
  this 
  form 
  has 
  the 
  longest 
  continuous 
  range 
  

   of 
  any 
  in 
  the 
  Jurassic 
  rocks. 
  It 
  has 
  been 
  found 
  in 
  6 
  horizons, 
  viz. 
  

   from 
  the 
  Great 
  Oolite 
  to 
  the 
  Coral 
  Rag 
  inclusive. 
  11 
  species 
  occur 
  

   in 
  the 
  Inferior 
  Oolite, 
  3 
  in 
  the 
  Fuller's 
  earth, 
  and 
  7 
  in 
  the 
  Great 
  

   Oolite. 
  

  

  Crustacea. 
  — 
  None. 
  

  

  Brtozoa. 
  — 
  Spiropora 
  straminea 
  and 
  Terebellaria 
  ramosissima 
  are 
  

   the 
  only 
  two 
  species 
  occurring 
  in 
  the 
  Forest 
  Marble. 
  The 
  former 
  

   occurs 
  in 
  the 
  Inferior 
  Oolite, 
  and 
  passes 
  to 
  the 
  Cornbrash 
  ; 
  the 
  latter 
  

   occurs 
  in 
  the 
  Fuller's 
  Earth, 
  Great 
  Oolite, 
  and 
  Coral 
  Rag. 
  31 
  species 
  

   are 
  known 
  in 
  the 
  Great 
  Oolite, 
  and 
  17 
  in 
  the 
  Inferior 
  Oolite. 
  We 
  

   should 
  hardly 
  expect 
  to 
  find 
  this 
  class 
  well 
  represented 
  in 
  the 
  Forest 
  

   Marble 
  or 
  the 
  Fuller's 
  Earth, 
  the 
  argillaceous 
  nature 
  of 
  the 
  latter 
  

   and 
  the 
  fragmentary 
  or 
  triturated 
  nature 
  of 
  the 
  former 
  being 
  

   highly 
  unfavourable 
  for 
  their 
  development 
  or 
  preservation. 
  

  

  JBrachiopoda. 
  — 
  Terebratula, 
  Waldheimia, 
  and 
  Khynclionella 
  are 
  

   the 
  only 
  3 
  genera 
  in 
  the 
  Forest 
  Marble, 
  and 
  they 
  include 
  10 
  species, 
  

   viz. 
  Terebratula 
  4, 
  Waldheimia 
  3, 
  and 
  RliynclioneZla 
  3. 
  8 
  of 
  the 
  

   10 
  species 
  are 
  common 
  to 
  the 
  Cornbrash, 
  and 
  3 
  to 
  the 
  Kellaways 
  

   Rock. 
  

  

  Lamellibranchiata. 
  Mommy 
  aria. 
  — 
  9 
  genera 
  and 
  24 
  species 
  occur 
  

   in 
  the 
  Forest 
  Marble. 
  The 
  genus 
  Pecten 
  only 
  is 
  comparatively 
  

   largely 
  represented, 
  but 
  sparingly 
  so 
  as 
  compared 
  with 
  other 
  for- 
  

   mations. 
  9 
  species 
  represent 
  this 
  prolific 
  genus. 
  Out 
  of 
  the 
  2 
  9 
  4 
  

   occurring 
  here, 
  ^ 
  7 
  have 
  appeared 
  before, 
  and 
  7 
  of 
  the 
  9 
  genera 
  

   and 
  14 
  of 
  the 
  species 
  pass 
  to 
  the 
  Cornbrash 
  ; 
  so 
  that 
  in 
  reality 
  only 
  

   4 
  genera 
  and 
  4 
  species 
  belong 
  specially 
  to 
  the 
  Forest 
  Marble 
  : 
  they 
  

   are 
  Gervillia 
  Waltoni, 
  Ostrea 
  wiltonensis, 
  Pecten 
  divaricatus, 
  and 
  

   Perna 
  obliqua. 
  The 
  poverty 
  of 
  species 
  in 
  certain 
  groups, 
  and 
  total 
  

   want 
  of 
  representation 
  of 
  many 
  whole 
  classes 
  in 
  the 
  Forest 
  Marble 
  

   is 
  readily 
  accounted 
  for 
  through 
  the 
  nature 
  of 
  the 
  deposit 
  and 
  the 
  

   mode 
  of 
  its 
  accumulation 
  ; 
  for, 
  as 
  we 
  shall 
  see, 
  no 
  Nautili, 
  no 
  Pisces, 
  

   no 
  Reptilia, 
  and 
  no 
  Mammalia 
  have 
  yet 
  occurred 
  with 
  all 
  the 
  

   research 
  that 
  this 
  group 
  has 
  undergone. 
  

  

  Dimyaria. 
  — 
  19 
  genera 
  and 
  39 
  species 
  have 
  been 
  obtained 
  from 
  

   the 
  Forest 
  Marble 
  ; 
  } 
  § 
  are 
  also 
  in 
  the 
  horizons 
  below, 
  and 
  \ 
  \ 
  

   pass 
  to 
  the 
  Cornbrash. 
  The 
  two 
  chief 
  genera 
  are 
  Astarte 
  and 
  

   Trigonia. 
  The 
  • 
  former 
  possesses 
  8 
  species 
  and 
  the 
  latter 
  6 
  ; 
  12 
  

   genera 
  yield 
  only 
  1 
  species 
  each, 
  thus 
  clearly 
  showing 
  the 
  change 
  

   in 
  the 
  deposits 
  at 
  the 
  termination 
  of 
  the 
  deeper-sea 
  condition 
  of 
  the 
  

   Great 
  Oolite, 
  in 
  which 
  no 
  less 
  than 
  40 
  genera 
  and 
  185 
  species 
  are 
  

   known. 
  This 
  paucity 
  is 
  striking 
  and 
  in 
  conformity 
  with 
  the 
  

   physical 
  conditions 
  that 
  prevailed. 
  Pholadomya, 
  Myacites, 
  Modiola, 
  

   Lucina, 
  Goniomya, 
  Area, 
  Cardium, 
  Ceromya, 
  and 
  Cyprina, 
  all 
  

   moderately 
  deep-sea 
  forms, 
  are 
  almost 
  totally 
  unrepresented, 
  yet 
  

   the 
  succeeding 
  Cornbrash 
  has 
  yielded 
  33 
  genera 
  and 
  98 
  species. 
  

  

  Gasteropoda. 
  — 
  19 
  genera 
  and 
  43 
  species 
  have 
  been 
  recorded 
  from 
  

  

  