﻿174 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  PLATE 
  3 
  

  

  i 
  A 
  calyx 
  of 
  Zaphrentis 
  with 
  a 
  number 
  of 
  tube 
  openings 
  of 
  

   Gitonia 
  corallophila 
  

  

  2 
  Tubes 
  of 
  the 
  same 
  character 
  opening 
  outward 
  through 
  the 
  

  

  lateral 
  walls 
  of 
  Zaphrentis 
  ; 
  much 
  enlarged 
  

  

  3 
  A 
  Zaphrentis 
  with 
  tube 
  openings 
  at 
  the 
  base 
  

  

  4 
  A 
  Cystiphyllum 
  with 
  short 
  tubes 
  opening 
  outward 
  through 
  

  

  the 
  thecal 
  walls 
  

  

  5, 
  6 
  A 
  Zaphrentis 
  from 
  two 
  points 
  of 
  view 
  to 
  show 
  the 
  course 
  of 
  a 
  

   tube 
  of 
  Gitonia 
  corallophila 
  with 
  both 
  ends 
  

   opening 
  outward 
  in 
  the 
  calyx 
  

  

  All 
  these 
  specimens 
  are 
  from 
  the 
  Onondaga 
  limestone 
  

   (Lower 
  Devonic). 
  

   7 
  Caunopora 
  — 
  a 
  schematic 
  section 
  showing 
  the 
  Syringopora- 
  

   or 
  Auloporalike 
  tubes 
  overgrown 
  by 
  the 
  Stromatopora 
  sub- 
  

   stance 
  ; 
  coral 
  on 
  coral 
  

  

  8-i 
  i 
  Enlarged 
  figures 
  ofSpirorbis 
  angulata 
  Hall, 
  a 
  worm 
  

   tube 
  from 
  the 
  Hamilton 
  group 
  of 
  New 
  York. 
  These 
  speci- 
  

   mens 
  are 
  silica 
  replacements 
  etched 
  from 
  limestone 
  (Menteth 
  

   limestone), 
  and 
  show 
  the 
  tendency 
  of 
  the 
  tube 
  to 
  unwind 
  

   in 
  a 
  lax 
  spiral 
  as 
  soon 
  as 
  fixation 
  is 
  firmly 
  established. 
  

  

  