﻿1863.] 
  DUNCAN 
  WEST 
  INDIAN 
  COBALS. 
  33 
  

  

  whether 
  the 
  Astrocoenice 
  be 
  not 
  possessed 
  of 
  dentate 
  septa. 
  On 
  an 
  ex- 
  

   amination 
  of 
  the 
  septa 
  of 
  certain 
  species 
  of 
  the 
  Eusmilince, 
  fine 
  granu- 
  

   lar 
  projections 
  and 
  papillary 
  eminences 
  amounting 
  to 
  a 
  serrate 
  edge 
  

   were 
  noticed, 
  and 
  in 
  certain 
  species 
  of 
  Astrceince 
  no 
  greater 
  struc- 
  

   tural 
  additions 
  to 
  the 
  septa 
  were 
  observed. 
  Series 
  of 
  granules 
  and 
  

   papillae 
  on 
  the 
  sides 
  of 
  the 
  lamellae 
  of 
  Eusmilince 
  are 
  very 
  frequently 
  

   terminated 
  on 
  the 
  free 
  edge 
  of 
  the 
  septa 
  by 
  corresponding 
  points, 
  

   and 
  the 
  septa 
  thus 
  marked 
  are 
  quite 
  as 
  liable 
  to 
  be 
  deemed 
  of 
  an 
  

   Astraean 
  nature 
  as 
  the 
  septa 
  of 
  many 
  species 
  of 
  Isastrcea, 
  Tham- 
  

   nastrcea, 
  Siderastrcea, 
  <fec. 
  

  

  After 
  an 
  elaborate 
  examination 
  of 
  this 
  point, 
  Mr. 
  Lonsdale 
  adds, 
  

   " 
  The 
  foregoing 
  statements 
  are 
  deemed 
  sufficient 
  to 
  justify 
  caution 
  

   in 
  using 
  the 
  outline 
  of 
  the 
  edge 
  of 
  lamellae 
  as 
  the 
  basis 
  of 
  sub- 
  

   families." 
  

  

  The 
  lamellae 
  of 
  the 
  fossil 
  noticed 
  by 
  Mr. 
  Lonsdale 
  are 
  highly 
  

   granular 
  and 
  papillated, 
  the 
  series 
  of 
  points 
  ending 
  on 
  the 
  free 
  septal 
  

   upper 
  margin, 
  rendering 
  it 
  regularly 
  and 
  finely 
  papillary. 
  He 
  con- 
  

   sidered 
  the 
  Eusmilian 
  peculiarity 
  to 
  remain, 
  because 
  the 
  distinction 
  

   between 
  papillated 
  and 
  smooth-edged 
  septa 
  had 
  not 
  been 
  considered 
  

   zoologically. 
  In 
  the 
  specimen 
  I 
  have 
  described, 
  the 
  papillae 
  evidently 
  

   carry 
  upwards 
  with 
  them 
  a 
  portion 
  of 
  the 
  laminated 
  sclerenchyma 
  

   of 
  the 
  septa, 
  and 
  a 
  very* 
  visible 
  serration 
  results 
  which 
  cannot 
  be 
  

   admitted 
  as 
  Eusmilian. 
  

  

  The 
  genus 
  Rhipidogyra, 
  like 
  many 
  others, 
  has 
  had 
  grave 
  changes 
  

   made 
  in 
  its 
  diagnosis 
  since 
  its 
  formation, 
  and 
  even 
  in 
  a 
  few 
  years 
  

   it 
  has 
  lost 
  several 
  species, 
  but 
  gained 
  a 
  columella 
  ! 
  It 
  is 
  now 
  a 
  

   fossil 
  genus, 
  and 
  it 
  is 
  quite 
  possible 
  that, 
  as 
  in 
  the 
  cases 
  of 
  Monili- 
  

   vedtia 
  and 
  TkecosmiUa, 
  two 
  tolerably 
  common 
  genera, 
  the 
  Eusmilian 
  

   characters 
  will 
  have 
  to 
  be 
  rejected. 
  

  

  A 
  reference 
  to 
  the 
  description 
  of 
  the 
  genus 
  (Hist. 
  Nat. 
  des 
  Coral- 
  

   liaires, 
  vol. 
  ii. 
  p. 
  214) 
  will 
  render 
  it 
  evident 
  that 
  there 
  is 
  much 
  con- 
  

   fusion 
  concerning 
  the 
  species 
  to 
  be 
  comprehended 
  in 
  it, 
  and 
  the 
  short 
  

   notices 
  of 
  those 
  recognized 
  would 
  imply 
  that 
  they 
  had 
  not 
  been 
  deter- 
  

   mined 
  from 
  good 
  specimens. 
  Thus 
  Rhipidogyra 
  occitanica 
  is 
  dismissed 
  

   with 
  a 
  reference 
  to 
  R. 
  Martinana, 
  which 
  in 
  its 
  turn 
  has 
  three 
  lines 
  

   allotted 
  to 
  it. 
  But, 
  fortunately, 
  Reuss 
  has 
  described 
  a 
  specimen 
  of 
  

   R. 
  occitanica 
  from 
  Gosau, 
  and 
  notices 
  both 
  the 
  markings 
  of 
  the 
  

   lamellae 
  by 
  series 
  of 
  fine 
  granules 
  and 
  the 
  presence 
  of 
  an 
  epitheca 
  in- 
  

   feriorly 
  on 
  the 
  base 
  of 
  the 
  Coral. 
  His 
  description 
  of 
  Rhipidogyra 
  

   undidata 
  is 
  but 
  slightly 
  given 
  by 
  Edwards 
  and 
  Haime, 
  and 
  it 
  con- 
  

   tains 
  (Denkschr. 
  der 
  Wiener 
  Akad. 
  der 
  Wiss., 
  185-1, 
  p. 
  93) 
  a 
  notice 
  

   of 
  the 
  granular 
  condition 
  of 
  the 
  lower 
  costae. 
  Granular 
  septa 
  and 
  

   costae 
  are 
  thus 
  added 
  to 
  the 
  diagnosis 
  of 
  the 
  genus, 
  and 
  a 
  decided 
  

   epitheca 
  also. 
  

  

  The 
  genus 
  is 
  distinguished 
  from 
  Pachygyra 
  by 
  the 
  absence 
  of 
  " 
  a 
  

   false 
  costal 
  coenenchyma" 
  *. 
  Now 
  this 
  conveys 
  the 
  impression 
  that 
  

   the 
  Rhipidogyrce 
  have 
  no 
  tissue 
  between 
  the 
  costae 
  and 
  the 
  exothecal 
  

   dissepiments, 
  and 
  there 
  is 
  no 
  mention 
  of 
  any 
  in 
  the 
  descriptions 
  of 
  

   the 
  species. 
  In 
  Michelins 
  vertical 
  section 
  of 
  Rhipidogyra 
  (Lobo- 
  

  

  * 
  Edwards 
  and 
  Haime, 
  op. 
  cif. 
  p. 
  214. 
  

   VOL. 
  XX. 
  — 
  PAST 
  I. 
  D 
  

  

  