﻿PLATE 
  XII. 
  

  

  Fejtestella 
  papyulipora 
  Hall. 
  

  

  Page 
  123. 
  

  

  Fig. 
  1. 
  The 
  non-poriferous 
  surface 
  of 
  a 
  fragment 
  of 
  a 
  frond, 
  natural 
  size. 
  

   Fie. 
  2. 
  An 
  enlargement 
  of 
  a 
  Dortion 
  of 
  the 
  same 
  to 
  show 
  the 
  character 
  of 
  the 
  

  

  surface 
  and 
  mode 
  of 
  reticulation. 
  

   Fig. 
  3. 
  A 
  similar 
  fragment, 
  having 
  young 
  specimens 
  of 
  Lichenalia 
  and 
  Cera- 
  

  

  mopora 
  growing 
  upon 
  its 
  surface 
  (see 
  plate 
  7, 
  figs. 
  4 
  and 
  5, 
  and 
  

  

  plate 
  8. 
  figs. 
  1 
  and 
  2). 
  

   Fig. 
  4. 
  An 
  enlargement 
  from 
  a 
  portion 
  of 
  the 
  opposite 
  or 
  celluliferous 
  face 
  of 
  

  

  the 
  frond 
  fig. 
  3. 
  

   Fig. 
  5. 
  A 
  still 
  farther 
  enlargement 
  of 
  this 
  surface, 
  to 
  show 
  more 
  distinctly 
  the 
  

  

  arrangement 
  of 
  pores 
  and 
  the 
  line 
  of 
  nodes 
  on 
  the 
  median 
  crest. 
  

   Fig. 
  6. 
  An 
  enlargement 
  of 
  the 
  non-celluliferous 
  face 
  of 
  the 
  same 
  frond, 
  fig. 
  3, 
  

  

  showing 
  the 
  absence 
  of 
  striation 
  upon 
  the 
  surface. 
  

   Fig. 
  7. 
  A 
  portion 
  of 
  a 
  very 
  large 
  frond, 
  natural 
  size, 
  showing 
  the 
  general 
  aspect 
  

  

  of 
  the 
  species. 
  

   Fig. 
  8. 
  An 
  enlargement 
  of 
  the 
  surface 
  of 
  the 
  specimen 
  fig. 
  7, 
  showing 
  the 
  exist- 
  

   ence 
  of 
  very 
  fine 
  strife. 
  

   Fig. 
  9. 
  The 
  interior 
  of 
  a 
  frond, 
  retaining 
  the 
  cup-shaped 
  form. 
  The 
  surface 
  

  

  here 
  presented 
  is 
  non-celluliferous. 
  

  

  Fenestella 
  acmea 
  Hall. 
  

  

  Page 
  124. 
  

  

  Fig. 
  10. 
  The 
  outer 
  surface 
  of 
  a 
  funnel-shaped 
  frond, 
  presenting 
  the 
  celluliferous 
  

   side. 
  

  

  Fig. 
  11. 
  An 
  enlargement 
  of 
  a 
  part 
  to 
  show 
  the 
  arrangement 
  of 
  the 
  branches, 
  the 
  

   form 
  of 
  the 
  cells 
  and 
  the 
  median 
  ridge, 
  with 
  its 
  flattened 
  spreading 
  

   crest, 
  which 
  is 
  seen 
  on 
  some 
  of 
  the 
  rays 
  in 
  the 
  upper 
  part 
  of 
  the 
  

   figure, 
  and 
  on 
  all 
  below 
  the 
  bifurcation, 
  while 
  it 
  is 
  broken 
  away 
  

   in 
  places, 
  revealing 
  the 
  narrow 
  slit 
  thus 
  left, 
  which 
  passes 
  into 
  the 
  

   cavity 
  of 
  the 
  ray 
  below. 
  

  

  Fig. 
  12. 
  Another 
  fragment 
  of 
  the 
  same 
  species. 
  

  

  Fig. 
  13. 
  An 
  enlargement 
  from 
  a 
  part 
  of 
  the 
  preceding 
  specimen, 
  presenting 
  

   wider 
  fenestrules, 
  and 
  having 
  the 
  median 
  crest 
  entirely 
  removed, 
  

   showing 
  only 
  the 
  narrow 
  slit 
  passing 
  into 
  the 
  cavity 
  of 
  the 
  branch. 
  

   The 
  connecting 
  fenestrules 
  are 
  obscured 
  over 
  a 
  part 
  of 
  this 
  figure, 
  

   as 
  in 
  fig. 
  11. 
  

  

  Fig. 
  14. 
  An 
  enlargement, 
  to 
  two 
  diameters, 
  of 
  a 
  part 
  of 
  a 
  frond. 
  

  

  