﻿^ 
  

  

  E 
  

  

  ^s* 
  5 
  

  

  A. 
  Longitudinal 
  section, 
  X 
  8, 
  in 
  a 
  zoarium 
  containing 
  a 
  partially 
  envelop- 
  

  

  B. 
  Portion 
  of 
  fig. 
  A, 
  X 
  16. 
  C. 
  Part 
  of 
  longitudinal 
  section, 
  X 
  16, 
  through 
  

   a 
  tuberosity 
  where 
  the 
  tubes 
  are 
  broader. 
  D. 
  Portion 
  of 
  a 
  transverse 
  section 
  X 
  16. 
  E. 
  Tangential 
  section, 
  X 
  16, 
  show- 
  

   ing 
  the 
  larger 
  tubes 
  of 
  the 
  tuberosities 
  and 
  the 
  other 
  smaller 
  tubes. 
  Upper 
  Cretaceous 
  (Maastrichtian): 
  Royan, 
  France 
  

  

  FiQ. 
  20.— 
  Plethoporella 
  ramuiosa 
  D'Orbigny, 
  1853 
  

   ing 
  subcolony, 
  the 
  initial 
  tube 
  of 
  which 
  is 
  at 
  r 
  

  

  