﻿104 
  F. 
  W. 
  Sardeson 
  — 
  Lichenaria 
  typa 
  W. 
  <& 
  S. 
  

  

  in 
  force," 
  Beecher, 
  op. 
  cit. 
  But 
  it 
  may 
  be 
  an 
  open 
  question 
  

   whether 
  in 
  Lichenaria 
  we 
  see 
  an 
  early 
  stage 
  in 
  the 
  differentia- 
  

   tic 
  n 
  of 
  transverse 
  canals 
  from 
  stolons 
  or 
  whether 
  it 
  is 
  the 
  

   incipient 
  stage 
  of 
  mural 
  pore-building 
  by 
  the 
  lodging 
  of 
  pre- 
  

   existing 
  differentiated 
  canals 
  in 
  the 
  solid 
  wall, 
  as 
  explained 
  by 
  

   Moseley's 
  theory 
  regarding 
  Favosites. 
  Yery 
  probably, 
  how- 
  

   ever, 
  Beecher's 
  theory 
  was 
  suggested 
  less 
  from 
  this 
  kind 
  of 
  

   evidence, 
  than 
  from 
  a 
  supposed 
  Aulopora 
  stage 
  in 
  the 
  develop- 
  

   ment 
  of 
  Pleurodictyum, 
  since 
  if 
  Pleurodicti/um 
  were 
  derived 
  

   from 
  Aulopora 
  then 
  the 
  stolonal 
  structures 
  of 
  the 
  latter 
  would 
  

   be 
  the 
  origin 
  of 
  those 
  of 
  the 
  former 
  which 
  are 
  also 
  mural 
  

   pores. 
  But, 
  Auloporoid 
  growth 
  in 
  Lichenaria 
  is 
  not 
  a 
  normal 
  

   one, 
  as 
  said, 
  and 
  it 
  may 
  be 
  safely 
  added 
  that 
  there 
  is 
  no 
  Aulo- 
  

   pora 
  stage 
  in 
  the 
  ontogeny 
  of 
  Pleicrodictyum 
  lenticulare^ 
  the 
  

   tigures 
  2, 
  3 
  and 
  4, 
  pi. 
  9, 
  op. 
  cit., 
  being 
  palpably 
  erroneous, 
  and 
  

   figures 
  9, 
  10 
  and 
  11 
  representing 
  not 
  a 
  normal 
  corallum. 
  

  

  Lichenaria 
  appears 
  to 
  prove, 
  therefore, 
  that 
  stolons 
  and 
  

   transverse 
  canals 
  and 
  the 
  consequent 
  mural 
  pores 
  are 
  older 
  in 
  

   origin 
  than 
  the 
  oldest 
  known 
  Tabulata, 
  and 
  as 
  to 
  the 
  evidence, 
  it 
  

   does 
  not 
  prove 
  whether 
  canals 
  are 
  older 
  or 
  younger 
  than 
  

   stolons, 
  although 
  the 
  latter 
  may 
  be 
  the 
  case. 
  The 
  claim 
  that 
  

   Aulopora 
  is 
  ancestral 
  to 
  other 
  Tabulata 
  is 
  not 
  supported. 
  

  

  University 
  of 
  Minnesota, 
  Minneapolis, 
  

   May 
  27, 
  1899. 
  

  

  