﻿PLATE 
  IV. 
  

   Favosites 
  spixgerus 
  Hall. 
  

  

  Page 
  108. 
  

  

  Figs. 
  1, 
  2. 
  Upper 
  and 
  lateral 
  views 
  of 
  a 
  specimen 
  of 
  the 
  usual 
  character. 
  

  

  Fig. 
  3. 
  Vertical 
  section 
  of 
  a 
  similar 
  specimen, 
  showing 
  the 
  divergence 
  of 
  the 
  

  

  cells 
  and 
  the 
  distant 
  entire 
  diaphragms. 
  

   Fig. 
  4. 
  Vertical 
  section 
  of 
  a 
  specimen 
  with 
  larger 
  cells. 
  

   Fig. 
  5. 
  An 
  enlarged 
  oblique 
  view 
  of 
  a 
  portion 
  of 
  the 
  surface, 
  showing 
  the 
  

  

  irregular 
  cells 
  and 
  the 
  spiniform 
  projection 
  at 
  the 
  angles. 
  

  

  Favosites 
  Forbesi 
  var. 
  occidextalis 
  n. 
  var. 
  

  

  Page 
  108. 
  

  

  Fig. 
  6. 
  An 
  irregularly 
  hemispherical 
  specimen, 
  showing 
  small 
  cells 
  with 
  a 
  few 
  

   of 
  somewhat 
  larger 
  size. 
  

  

  Figs. 
  7, 
  8. 
  Turbinate 
  forms 
  with 
  large 
  irregular 
  cells, 
  the 
  lower 
  part 
  covered 
  by 
  

   the 
  epitheca. 
  

  

  Fig. 
  9. 
  The 
  upper 
  side 
  of 
  a 
  large 
  irregular 
  specimen. 
  

  

  Fig. 
  10. 
  Lateral 
  view 
  of 
  a 
  large 
  broadly 
  turbinate 
  specimen, 
  having 
  the 
  lower 
  

   part 
  covered 
  by 
  the 
  epitheca 
  and 
  showing 
  in 
  the 
  upper 
  part 
  an 
  

   irregular 
  distribution 
  of 
  large 
  and 
  small 
  angular 
  cells. 
  

  

  Fig. 
  11. 
  A 
  vertical 
  section 
  of 
  a 
  specimen 
  similar 
  to 
  fig. 
  8, 
  showing 
  the 
  closely 
  

   arranged 
  diaphragms. 
  

  

  Fig. 
  12. 
  An 
  enlarged 
  transverse 
  section, 
  showing 
  the 
  thick 
  vertical 
  walls. 
  

  

  Fig. 
  13. 
  Enlarged 
  vertical 
  section 
  showing 
  the 
  thick 
  walls 
  and 
  large 
  mural 
  

   pores. 
  

  

  Fig. 
  14. 
  The 
  natural 
  surface 
  of 
  a 
  well-preserved 
  specimen, 
  showing 
  the 
  granu- 
  

   lations 
  upon 
  the 
  diaphragms. 
  

  

  Fig. 
  15. 
  An 
  oblique 
  view 
  of 
  the 
  same. 
  In 
  the 
  figure 
  the 
  vertical 
  walls 
  are 
  not 
  

   sufficiently 
  elevated 
  above 
  the 
  diaphragms. 
  

  

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