﻿FIFTH 
  REPORT 
  OF 
  THE 
  DIRECTOR 
  I908 
  1 
  99 
  

  

  A 
  thick 
  calcareous 
  incrustation 
  is 
  found 
  between 
  the 
  axial 
  canal 
  

   formerly 
  occupied 
  by 
  the 
  axial 
  cell, 
  or 
  cells, 
  and 
  a 
  thin, 
  carbon- 
  

   aceous 
  outer 
  film. 
  The 
  axial 
  canal 
  becomes 
  visible 
  in 
  the 
  principal 
  

   branch 
  of 
  tlie 
  thallus 
  where 
  the 
  tube 
  is 
  crushed 
  [see 
  pi. 
  i, 
  fig", 
  i] 
  

   and 
  also 
  an 
  axial 
  canal 
  of 
  the 
  branchlets 
  can 
  be 
  seen 
  in 
  the 
  same 
  

   specimen 
  on 
  the 
  right-hand 
  side. 
  The 
  calcium 
  carbonate 
  of 
  the 
  

   fossil 
  contrasts 
  by 
  its 
  dark 
  brown 
  and 
  sometimes 
  amber 
  color 
  with 
  

   that 
  of 
  the 
  matrix 
  and 
  of 
  other 
  fossils 
  indicating 
  a 
  certain 
  amount 
  

   of 
  carbonaceous 
  matter 
  still 
  contained 
  in 
  it. 
  In 
  thin 
  sections 
  made 
  

   through 
  a 
  few 
  joints 
  a 
  deep 
  black 
  thin 
  layer 
  was 
  seen 
  on 
  the 
  out- 
  

   side 
  and 
  a 
  less 
  distinct 
  one 
  lining 
  the 
  axial 
  canal, 
  showing 
  that 
  the 
  

   calcareous 
  deposition 
  took 
  place 
  within 
  an 
  outer 
  membrane 
  or 
  

   gelatinous 
  sheath. 
  The 
  outer 
  black 
  layer 
  fails 
  to 
  show 
  traces 
  of 
  

   former 
  pores 
  and 
  the 
  calcareous 
  deposition 
  is 
  crystalline 
  and 
  devoid 
  

   of 
  structure. 
  

  

  Professor 
  Whitfield 
  describes 
  the 
  branchlets 
  or 
  pinnules 
  as 
  

   repeatedly 
  bifurcating. 
  The 
  fact, 
  however, 
  that 
  this 
  bifurcation 
  is 
  

   seen 
  in 
  both 
  the 
  longitudinal 
  and 
  transverse 
  sections 
  of 
  . 
  the 
  

   same 
  specimen 
  suggests 
  that 
  also- 
  in 
  the 
  branchlets 
  the 
  division 
  

   took 
  place 
  in 
  double 
  dichotomies 
  or 
  in 
  whorls 
  of 
  four 
  branches; 
  

   and 
  in 
  fact 
  in 
  one 
  place 
  [see 
  pi. 
  i, 
  fig. 
  i 
  at 
  a 
  and 
  b] 
  three 
  branchlets 
  

   are 
  seen 
  at 
  the 
  second 
  division 
  (at 
  a) 
  and 
  in 
  one 
  three 
  at 
  the 
  

   third 
  (at 
  b). 
  The 
  thallus 
  is 
  hence 
  composed 
  of 
  a 
  system 
  of 
  verti- 
  

   cils 
  of 
  branches. 
  The 
  joints 
  of 
  the 
  main 
  stem 
  are 
  cylindrical, 
  little 
  

   contracted 
  at 
  the 
  articulations, 
  those 
  of 
  the 
  branchlets, 
  however, 
  

   are 
  clavatc, 
  somewdiat 
  bulbous 
  at 
  the 
  distal 
  end 
  and 
  with 
  rounded 
  

   extremities. 
  The 
  terminal 
  branchlets 
  are 
  pyriform, 
  distinctly 
  

   pointed 
  at 
  the 
  distal 
  extremity 
  and 
  round 
  and 
  bulbous 
  at 
  the 
  other. 
  

  

  Thin 
  sections 
  through 
  the 
  few 
  fragments 
  of 
  joints 
  of 
  the 
  main 
  

   stem 
  and 
  branchlets 
  have 
  not 
  furnished 
  any 
  indication 
  of 
  the 
  pres- 
  

   ence 
  of 
  cavities 
  suggestive 
  of 
  conceptacles. 
  The 
  fructifications 
  may 
  

   have 
  consisted 
  of 
  terminal 
  sporangia 
  that 
  were 
  easily 
  detachable 
  

   and 
  were 
  lost, 
  or 
  we 
  may 
  have 
  only 
  sterile 
  thalli 
  before 
  us, 
  or 
  

   again, 
  the 
  terminal 
  pyriform 
  branchlets 
  may 
  have 
  contained 
  the 
  

   conceptacles 
  at 
  their 
  apexes 
  and 
  these 
  may 
  have 
  become 
  obscured 
  

   by 
  secondary 
  crystallization. 
  It 
  probably 
  will 
  require 
  more 
  material 
  

   than 
  is 
  available 
  now 
  to 
  discover 
  the 
  fertile 
  branches. 
  

  

  Professor 
  Whitfield 
  referred 
  this 
  form 
  to 
  the 
  coralline 
  algae 
  

   (Corallinaceae), 
  as 
  shown 
  by 
  the 
  name, 
  probably 
  on 
  good 
  ground 
  

   as 
  long 
  as 
  the 
  verticillate 
  arrangement 
  of 
  the 
  branchlets 
  of 
  the 
  

   second 
  and 
  third 
  orders 
  was 
  not 
  reco2"nized. 
  A 
  verticillate 
  

  

  