﻿E. 
  P. 
  TOMES 
  ON 
  LOWEE-OOLTTE 
  MADEEPOEAEIA. 
  417 
  

  

  some 
  indications 
  of 
  lateral 
  gemmation. 
  Bnt 
  I 
  have 
  since 
  met 
  with 
  

   some 
  specimens 
  which 
  appear 
  to 
  have 
  a 
  well-marked 
  though 
  porous 
  

   columella, 
  which, 
  so 
  far 
  as 
  I 
  know, 
  is 
  not 
  characteristic 
  of 
  Donacos- 
  

   milia 
  at 
  any 
  age. 
  

  

  Subfamily 
  Aste^inje. 
  

  

  Tribe 
  Lithophylliace^;. 
  

  

  Genus 
  Montlivaltia, 
  Lamoc. 
  

  

  Oppelismilia, 
  Duncan. 
  

  

  It 
  has 
  been 
  quite 
  fully 
  shown 
  by 
  M. 
  Milaschewitsch 
  how 
  much 
  this 
  

   genus 
  is 
  subject 
  to 
  rejuvenescence, 
  and 
  that 
  under 
  its 
  agency 
  forms 
  

   appear 
  which 
  at 
  first 
  sight 
  may 
  seem 
  to 
  be 
  quite 
  distinct 
  from 
  

   Montlivaltia. 
  Such, 
  as 
  pointed 
  out 
  by 
  him, 
  is 
  the 
  genus 
  Ojppelis- 
  

   railia, 
  the 
  brief 
  definition 
  of 
  which, 
  furnished 
  by 
  Prof. 
  Duncan, 
  is 
  

   that 
  of 
  a 
  Montlivaltia 
  with 
  calicular 
  gemmation. 
  The 
  process, 
  

   however, 
  by 
  which 
  the 
  example 
  which 
  became 
  the 
  type 
  of 
  the 
  

   genus 
  was 
  produced 
  is 
  quite 
  distinct 
  from 
  gemmation, 
  and 
  the 
  genus 
  

   thus 
  formed 
  must 
  give 
  way. 
  

  

  I 
  have 
  met 
  with 
  a 
  Montlivaltia 
  from 
  the 
  Trigonia-grit 
  of 
  Brown's 
  

   Hill, 
  near 
  Seven 
  Springs, 
  which, 
  while 
  it 
  fulfils 
  the 
  above 
  definition, 
  

   and 
  really 
  has 
  true 
  calicular 
  gemmation, 
  is 
  nevertheless 
  nothing 
  more 
  

   than 
  a 
  Montlivaltia, 
  and 
  of 
  a 
  species 
  which 
  is 
  by 
  no 
  means 
  un- 
  

   common 
  there. 
  But 
  up 
  to 
  this 
  time 
  only 
  one 
  example 
  having 
  gem- 
  

   mation 
  has 
  been 
  met 
  with. 
  In 
  that 
  part 
  of 
  the 
  corallum 
  consistent 
  

   with 
  the 
  position 
  of 
  the 
  upper 
  margin 
  of 
  the 
  wall 
  is 
  imbedded 
  a 
  

   young 
  corallite, 
  obviously 
  of 
  the 
  same 
  species 
  as 
  the 
  parent 
  one. 
  

   It 
  has 
  every 
  appearance 
  of 
  having 
  grown 
  from 
  the 
  top 
  of 
  the 
  wall, 
  

   and 
  both 
  calices 
  have 
  grown 
  together 
  and 
  have 
  pushed 
  each 
  other 
  

   out 
  of 
  shape. 
  There 
  is 
  no 
  proof, 
  however, 
  that 
  the 
  young 
  calice 
  

   was 
  not 
  produced 
  by 
  the 
  accidental 
  growth 
  of 
  an 
  ovum 
  in 
  a 
  part 
  of 
  

   the 
  calice 
  where 
  it 
  would 
  not 
  at 
  once 
  cause 
  the 
  death 
  of 
  the 
  parent. 
  

  

  Montlivaltia 
  tenutlamellosa, 
  Edw. 
  and 
  Haime, 
  Brit. 
  Poss. 
  Cor. 
  

   pt. 
  ii. 
  p. 
  130, 
  pi. 
  xxvi. 
  fig. 
  11 
  (1851). 
  

  

  As 
  is 
  the 
  case 
  with 
  so 
  many 
  of 
  the 
  Montlivaltice 
  of 
  the 
  Inferior 
  

   Oolite 
  of 
  Gloucestershire, 
  the 
  present 
  species 
  is 
  represented 
  by 
  indi- 
  

   viduals 
  which 
  have 
  a 
  very 
  dwarfed 
  growth. 
  

  

  Compared 
  with 
  the 
  figure 
  given 
  by 
  the 
  original 
  describers, 
  two 
  of 
  

   the 
  three 
  at 
  present 
  identified 
  specimens 
  do 
  not 
  exhibit 
  more 
  than 
  

   half, 
  and 
  the 
  third 
  not 
  more 
  than 
  three 
  fourths, 
  of 
  the 
  size 
  of 
  that 
  

   figure. 
  They 
  all 
  differ 
  also 
  in 
  having 
  a 
  less 
  elongated 
  fossula 
  and 
  

   more 
  crowded 
  septa. 
  There 
  are 
  from 
  175 
  to 
  180 
  septa 
  constituting 
  

   five 
  complete 
  cycles 
  and 
  one 
  incomplete 
  cycle. 
  In 
  all 
  of 
  them 
  the 
  

   epitheca 
  is 
  lost, 
  and 
  they 
  are 
  much 
  worn. 
  

  

  Two 
  have 
  been 
  collected 
  from 
  the 
  Crickley-Hill 
  reef, 
  and 
  one 
  from 
  

   the 
  Pisolite 
  at 
  Leckhampton. 
  

  

  Montlivaltia 
  concinna, 
  n. 
  sp. 
  

  

  The 
  corallum 
  is 
  small 
  and 
  pedunculate, 
  and 
  the 
  peduncle 
  is 
  two 
  

  

  