﻿The 
  Fauna 
  of 
  the 
  Niagaea 
  Group. 
  115 
  

  

  Callopoea 
  singularis. 
  

  

  Plate 
  10, 
  Figs. 
  1, 
  2. 
  

  

  Callopora 
  singularis 
  Hall. 
  Doc. 
  Edit. 
  28th 
  Rep. 
  St. 
  Mus. 
  Nat. 
  Hist. 
  Explana- 
  

   tion 
  of 
  pi. 
  10, 
  figs. 
  1, 
  2. 
  1876. 
  

  

  Frond 
  ramose, 
  solid, 
  diameter 
  of 
  branches 
  two 
  millimetres. 
  

   Cells 
  tubular, 
  oval, 
  or 
  polygonal, 
  arising 
  from 
  the 
  center 
  of 
  

   the 
  branch 
  and 
  gradually 
  diverging 
  till 
  near 
  the 
  surface 
  when 
  

   they 
  turn 
  and 
  open 
  nearly 
  directly 
  outward. 
  Cell-apertures 
  .3 
  

   mm. 
  in 
  length, 
  with 
  a 
  width 
  of 
  .2 
  mm., 
  irregularly 
  arranged, 
  

   varying 
  in 
  distance 
  from 
  contiguity 
  to 
  a 
  space 
  equal 
  to 
  the 
  

   length 
  of 
  the 
  aperture 
  ; 
  margins 
  distinctly 
  elevated, 
  frequently 
  

   crenulated 
  by 
  minute 
  spinules. 
  Intercellular 
  spaces 
  on 
  the 
  

   surface 
  occupied 
  by 
  minute 
  pits, 
  which 
  are 
  observable 
  only 
  

   on 
  well-preserved 
  specimens. 
  

  

  Translucent 
  sections 
  of 
  the 
  stipes 
  or 
  branches 
  present 
  no 
  

   evidence 
  of 
  intercellular 
  vesiculose 
  structure, 
  and 
  have 
  all 
  the 
  

   aspect 
  of 
  a 
  Trematopora. 
  This 
  condition 
  may 
  come 
  from 
  a 
  

   solidifying 
  of 
  the 
  intercellular 
  substance 
  during 
  the 
  process 
  

   of 
  petrifaction, 
  leaving 
  only 
  the 
  intercellular 
  pits 
  upon 
  the 
  

   surface. 
  

  

  Callopora 
  elegaxtula. 
  

  

  Callopora 
  elegantula 
  Hall. 
  Pal. 
  N. 
  Y., 
  vol. 
  ii, 
  p. 
  144, 
  pi. 
  40, 
  figs. 
  la-l?». 
  1852. 
  

  

  This 
  species 
  has 
  recently 
  been 
  found 
  at 
  Waldron. 
  It 
  pre- 
  

   serves 
  the 
  characters 
  so 
  well 
  shown 
  in 
  the 
  same 
  species 
  from 
  

   the 
  Niagara 
  formation 
  in 
  New 
  York. 
  

  

  Callopora 
  exsul. 
  

  

  Plate 
  9, 
  Figs. 
  3, 
  L 
  

  

  Alveolites 
  exsul 
  Hall. 
  Doo. 
  Edit. 
  28th 
  Rep. 
  St. 
  Mus. 
  Nat. 
  Hist. 
  Explauatlou 
  of 
  

   pi. 
  9, 
  figs. 
  3, 
  4. 
  1876. 
  

  

  Bryozoum 
  consisting 
  of 
  lamellose 
  expansions, 
  free 
  or 
  in- 
  

   crusting 
  other 
  organic 
  bodies, 
  celluliferous 
  on 
  one 
  side 
  ; 
  lower 
  

   surface 
  formed 
  of 
  a 
  wrinkled 
  epitheca 
  ; 
  substance' 
  of 
  frond 
  

   sometimes 
  very 
  thin, 
  and 
  often 
  thickened 
  by 
  successive 
  accre- 
  

   tions 
  of 
  growth. 
  Cell-apertures 
  oval, 
  from 
  .3 
  to 
  .5 
  mm. 
  in 
  

   length, 
  and 
  usually 
  about 
  two-thirds 
  as 
  wide 
  as 
  long, 
  some- 
  

  

  