578  MADREPORARIA  FROM  THE  SUTTON  STONE.  [Nov.  1 893, 
of  the  figure  are  cut  though  almost  longitudinally,  and  in  a  manner  to 
show  their  thickness  and  the  prominence  of  the  pseudo-synapticulae. 
The  columella  exhibits  the  radiate  arrangement  of  the  lines  of  granules 
of  which  it  is  composed.  The  nature  and  frequency  of  the  dissepiments 
are  also  shown  in  the  figure.  Magnified  six  times. 
Astrocoenia  ramosa.  A  magnified  representation  of  a  section  taken  hori¬ 
zontally  near  the  base,  showing  the  central  corallites  with  their  well- 
defined  and  closely-attached  walls,  free  from  any  intervening  tissue, 
and  showing  also  the  addition  of  stereoplasm,  which  increases  in 
quantity  as  the  corallites  approach  the  outside  of  the  corallum.  Mag¬ 
nified  three  times.  A  transverse  section  of  these  corallites  taken  near 
the  calice  would  present  much  the  same  appearance  as  that  shown  by 
fig.  3  in  pi.  viii.  of  Reuss’s  fine  work  on  Cretaceous  Madreporaria. 
Stelidioseris  gihbosa.  A  portion  of  the  upper  surface,  haying  a  small 
gemmiparous  calice  between  four  of  ordinary  size,  showing  the  mode 
of  increase  by  budding.  Magnified  four  times. 
Discussion  (on  the  two  preceding  Papers). 
Mr.  Etheridge  alluded  to  the  difficulty  attached  to  the  better 
determination  of  the  many  British  species  of  the  genus  Astrocoenia. 
No  less  than  twelve  forms  are  recognized  as  occurring  in  the  Lower 
Lias  of  the  Sutton  Stone,  near  Brocastle,  Glamorganshire.  The 
affinities  of  the  Astrocoenice  given  in  Mr.  Tomes’s  first  paper  con¬ 
stitute  an  important  addition  to  the  literature  of  the  genus  and  its 
distribution:  six  species  are  critically  examined.  The  new  genus 
Styloseris  [Stelidioseris  j  proposed  by  Mr.  Tomes,  if  published,  would 
clear  up  certain  anomalies  respecting  the  Astrocoenice.  The  speaker 
did  not  doubt  that  the  critical  research  bestowed  upon  Styloseris 
[, Stelidioseris ],  with  its  affinities  and  differences  from  Astrocoenice , 
would  be  accepted  on  close  examination.  The  paper  would  facili¬ 
tate  the  better  classification  and  structure  of  this  group  of  the 
Astraeidse. 
Dr.  G.  J.  Hinde  appreciated  the  efforts  of  the  Author  to  deter¬ 
mine  the  real  characters  of  the  genus  Astrocoenia ,  which  could  only 
be  ascertained  from  a  study  of  the  typical  species  from  the  Cretaceous 
strata  of  Gosau.  Much  of  the  difference  of  opinion  as  to  the  nature 
and  systematic  position  of  the  corals  from  the  Lower  Lias  of  Sutton 
which  had  been  assigned  by  the  late  Prof.  Duncan  to  Astrocoenia , 
Edwards  and  Haime,  and  subsequently  by  Mr.  Tomes  to  the  genus 
Stylastrcea ,  Eromentel,  arose  from  the  fact  that  microscopic  sections 
of  these  forms  had  not  been  made. 
It  was  a  striking  commentary  on  the  importance  of  microscopic 
sections  that  the  Author  had  now  selected  as  the  type  of  his  new 
genus,  Styloseris  [ Stelidioseris ],  the  identical  specimen  which  had 
been  previously  chosen  by  Prof.  Duncan  to  illustrate  the  specific 
characters  and  to  justify  the  position  in  the  genus  Astrocoenia  in 
which  he  had  placed  it. 
Pig.  5. 
Pig.  6. 
