﻿PLATE 
  X. 
  

  

  CALLOPORA 
  SI23TGULARIS 
  Hall. 
  

   Page 
  115. 
  

   Figs. 
  1, 
  2. 
  A 
  specimen, 
  natural 
  size, 
  and 
  an 
  enlargement, 
  showing 
  the 
  arrange- 
  

   ment 
  of 
  the 
  cells. 
  The 
  interstices 
  of 
  the 
  intercellular 
  spaces 
  as 
  

   represented 
  are 
  too 
  small 
  and 
  indistinct. 
  

  

  TREMATOPORA 
  INFREQTTENS 
  Hall 
  

   Page 
  111. 
  

  

  Fig. 
  3. 
  A 
  fragment 
  of 
  shale, 
  with 
  a 
  group 
  of 
  stems 
  of 
  which 
  one 
  specimen 
  is 
  

  

  of 
  this 
  species. 
  Natural 
  size. 
  

   Fig. 
  4. 
  Enlargement 
  of 
  a 
  bifurcation 
  from 
  the 
  individual 
  on 
  the 
  right 
  hand 
  side 
  

  

  of 
  the 
  specimen 
  fig. 
  3. 
  

  

  Trematopora 
  osculum 
  Hall 
  

  

  Page 
  110. 
  

  

  Figs. 
  5, 
  6. 
  A 
  specimen, 
  natural 
  size, 
  and 
  enlarged, 
  showing 
  cells 
  of 
  smaller 
  size 
  

  

  than 
  the 
  preceding 
  species. 
  

   Figs. 
  7, 
  8. 
  A 
  specimen, 
  natural 
  size, 
  and 
  enlarged, 
  showing 
  the 
  cell-apertures 
  

  

  more 
  crowded 
  and 
  more 
  exsert 
  than 
  in 
  the 
  last. 
  

   Figs. 
  11, 
  12. 
  A 
  specimen 
  which 
  appears 
  to 
  have 
  been 
  tubular, 
  with 
  scattered 
  

  

  pores. 
  The 
  enlargement, 
  fig. 
  12, 
  does 
  not 
  fully 
  represent 
  the 
  

  

  object. 
  

   Fig. 
  13. 
  A 
  specimen, 
  natural 
  size. 
  

   Fig. 
  14. 
  The 
  same 
  enlarged. 
  

  

  Trematopora 
  subimbricata 
  Hall 
  

  

  Trans. 
  Alb. 
  Inst., 
  vol. 
  X. 
  

  

  Figs. 
  9, 
  10. 
  A 
  specimen 
  showing 
  arrangement 
  of 
  the 
  cells 
  opening 
  obliquely 
  

   upward, 
  and 
  the 
  upper 
  margin 
  not 
  elevated. 
  

  

  TrematopWa 
  yaria 
  Hall 
  

  

  Page 
  111. 
  

  

  Figs. 
  15. 
  16. 
  A 
  specimen, 
  natural 
  size 
  and 
  enlarged. 
  The 
  cell-apertures 
  appear 
  

   to 
  have 
  been 
  worn 
  or 
  dissolved 
  away, 
  giving 
  the 
  appearance 
  of 
  

   double 
  cell-walls. 
  Enlargement 
  eight 
  diameters. 
  

  

  Figs. 
  17, 
  18. 
  Another 
  individual 
  showing 
  the 
  apertures 
  reduced 
  in 
  size 
  by 
  the 
  

   contracted 
  margins. 
  Enlargement 
  about 
  six 
  diameters. 
  

  

  Figs. 
  19, 
  20. 
  A 
  specimen 
  in 
  which 
  the 
  cells 
  are 
  irregular 
  in 
  size, 
  some 
  of 
  them 
  

   with 
  elevated 
  margins 
  and 
  others 
  without. 
  

  

  Figs. 
  21, 
  22. 
  A 
  thickened 
  branching 
  form, 
  with 
  the 
  branches 
  flattened 
  above, 
  

   and 
  showing 
  other 
  variations 
  in 
  the 
  form 
  and 
  size 
  of 
  cells. 
  This 
  

   and 
  the 
  preceding 
  enlargement 
  are 
  four 
  diameters 
  each. 
  

  

  Fig. 
  23. 
  Tranverse 
  section 
  of 
  the 
  lower 
  part 
  of 
  the 
  specimen 
  fig. 
  21, 
  showing 
  

   a 
  hollow 
  tube, 
  and 
  the 
  mode 
  of 
  growth 
  of 
  the 
  cells. 
  

  

  