﻿Report 
  of 
  the 
  State 
  Geologist, 
  

  

  911 
  

  

  both 
  the 
  branches 
  and 
  dissepiments 
  are 
  carinated. 
  The 
  carinaeare 
  

  

  very 
  much 
  enlarged 
  above, 
  and 
  so 
  exactly 
  resemble 
  the 
  branches 
  

  

  and 
  dissepim 
  ents 
  of 
  the 
  non-cellu- 
  . 
  61 
  

  

  liferous 
  face 
  that 
  it 
  is 
  impossible 
  

  

  to 
  distinguish 
  one 
  from 
  the 
  

  

  other. 
  The 
  cell 
  apertures 
  are 
  

  

  not 
  arranged 
  in 
  straight 
  rows 
  

  

  as 
  in 
  the 
  preceding 
  genus, 
  but 
  

  

  around 
  the 
  fenestrules, 
  there 
  

  

  being 
  two 
  cell 
  apertures 
  on 
  each 
  fenestrule. 
  

  

  This 
  genus 
  differs 
  from 
  Tectulipora 
  in 
  having 
  sinuous 
  or 
  zig- 
  

   zag 
  branches, 
  but 
  the 
  most 
  important 
  point 
  of 
  difference 
  is 
  the 
  

   oval 
  arrangement 
  of 
  the 
  cell 
  apertures 
  around 
  the 
  fenestrules. 
  

   Fig. 
  61 
  shows 
  the 
  carinae 
  of 
  the 
  dissepiments 
  and 
  branches. 
  

  

  FENESTRALIA, 
  Pbout. 
  

  

  (Trans. 
  Acad. 
  Sciences, 
  St. 
  Louis, 
  1858.) 
  

  

  "This 
  Fenestella 
  is 
  characterized 
  by 
  a 
  double 
  row 
  of 
  cell 
  

  

  apertures 
  on 
  each 
  side 
  of 
  the 
  mid 
  rib, 
  without 
  a 
  divisional 
  keel 
  

  

  between 
  the 
  two 
  series 
  of 
  pores 
  upon 
  the 
  sides. 
  * 
  * 
  * 
  The 
  

  

  existence 
  of 
  two 
  rows 
  of 
  pores 
  on 
  each 
  side 
  without 
  a 
  separating 
  

   keel 
  entitles 
  it 
  to 
  be 
  ranked 
  as 
  a 
  sub-genera 
  of 
  Fenestella." 
  

  

  I 
  have 
  seen 
  no 
  specimen 
  of 
  this 
  form, 
  but 
  give 
  the 
  original 
  

   description 
  and 
  illustrations 
  of 
  Mr. 
  Prout. 
  

  

  