﻿102 
  

  

  PLATE 
  II 
  

  

  Clionolithes 
  radicans, 
  a 
  single 
  cluster 
  of 
  tube 
  

   casts, 
  x 
  5 
  in 
  the 
  substance 
  of 
  the 
  shell 
  ofAtrypa 
  retic- 
  

   ularis 
  from 
  the 
  Chemung 
  sandstone 
  of 
  Mansfield, 
  Pa. 
  

  

  The 
  same. 
  A 
  silicified 
  replacement 
  of 
  a 
  tube 
  cluster 
  within 
  

   the 
  shell 
  substance 
  ofLeptostrophia 
  magnifica 
  

   Hall, 
  standing 
  in 
  relief 
  on 
  the 
  surface 
  of 
  the 
  valve. 
  From 
  

   an 
  enlarged 
  photograph, 
  which 
  also 
  shows 
  the 
  casts 
  of 
  

   the 
  small 
  tubules 
  constituting 
  a 
  proper 
  part 
  of 
  the 
  

   structure 
  of 
  this 
  shell 
  and 
  through 
  one 
  of 
  which 
  it 
  is 
  prob- 
  

   able 
  that 
  the 
  sponge 
  entered. 
  From 
  the 
  Grande 
  Greve 
  

   limestone 
  (Lower 
  Devonic) 
  Gaspe" 
  

  

  Clinolithes 
  rept 
  an 
  s 
  ; 
  sparse, 
  diffuse 
  tubules 
  in 
  the 
  sub- 
  

   stance 
  of 
  a 
  shell 
  of 
  Leptostrophia 
  oriskania, 
  Oris- 
  

   kany 
  limestone, 
  Becraft 
  mountain, 
  N. 
  Y. 
  Greatly 
  enlarged 
  

  

  