﻿BIHANG 
  TILL 
  K. 
  SV. 
  VET.-AKAD. 
  HANDL. 
  BAND. 
  6. 
  N:0 
  13. 
  23 
  

  

  Corrections. 
  

  

  When 
  this 
  paper 
  already 
  had 
  been 
  published, 
  Prof. 
  Brög- 
  

   GER 
  told 
  me, 
  that 
  he 
  did 
  not 
  share 
  my 
  views 
  on 
  the 
  structure 
  

   of 
  Dictyonema 
  JiabeUiformis, 
  and 
  he 
  considers 
  that 
  it 
  really 
  

   has 
  its 
  branches 
  arranged 
  in 
  a 
  funnel 
  or 
  inverted 
  cone 
  and 
  

   that 
  it 
  is 
  endowed 
  with 
  hydrothecae 
  resembling 
  those 
  of 
  the 
  

   other 
  graptolites. 
  The 
  specimens 
  at 
  my 
  command, 
  when 
  I 
  

   gave 
  the 
  description 
  on 
  page 
  20, 
  were 
  such 
  that 
  I 
  could 
  

   but 
  think 
  that 
  Dictyonema 
  forms 
  a 
  flat 
  lamina, 
  nor 
  did 
  I 
  see 
  

   any 
  organs, 
  that 
  might 
  be 
  interpreted 
  as 
  hydrothecae, 
  only 
  the 
  

   processes, 
  which 
  often 
  are 
  characterized 
  through 
  a 
  longitudinal, 
  

   impressed 
  line 
  on 
  the 
  hydrosoma 
  and 
  are 
  prolonged 
  in 
  a 
  

   small 
  apex. 
  These 
  processes 
  emit 
  a 
  filament 
  to 
  the 
  nearest 
  

   parallel 
  branch. 
  

  

  Having 
  heard 
  Prof. 
  Brögger's 
  opinion, 
  I 
  found 
  in 
  the 
  

   Museum 
  of 
  the 
  Swedish 
  Geological 
  Survey 
  some 
  well 
  pre- 
  

   served 
  specimens 
  in 
  demi-relief, 
  and 
  I 
  examined 
  them 
  as 
  

   accurately 
  as 
  possible. 
  In 
  splitting 
  the 
  slate 
  I 
  found, 
  that 
  

   a 
  lower 
  lamina 
  of 
  the 
  branching 
  hydrosoma 
  really 
  originated 
  

   from 
  the 
  same 
  sicula 
  as 
  the 
  upper 
  lamina 
  of 
  the 
  hydrosoma. 
  

   On 
  the 
  lateral 
  branches 
  real 
  hydrothec^ 
  were 
  apparent, 
  re- 
  

   sembling 
  those 
  of 
  the 
  Dichograptidse. 
  That 
  they 
  are 
  so 
  rarely 
  

   observed, 
  depends 
  probably 
  on 
  the 
  circumstance, 
  that 
  they 
  

   are 
  directed 
  inwardly 
  toward 
  the 
  centre 
  and 
  that 
  they 
  are 
  

   covered 
  by 
  the 
  polypary 
  when 
  compressed 
  in 
  the 
  slate. 
  On 
  

   the 
  lateral 
  branches 
  they 
  are 
  sometimes 
  visible, 
  because 
  these 
  

   are 
  directed 
  outward. 
  

  

  