﻿BIHANG 
  TILL 
  K. 
  SV. 
  VET.-AKAD. 
  HANDL. 
  BAND. 
  G. 
  N:0 
  13. 
  21 
  

  

  The 
  obloug-triangular 
  liydrosoma, 
  whose 
  upper 
  border- 
  

   line 
  is 
  faintly 
  curved, 
  arises 
  from 
  the 
  sicula 
  by 
  reiterated 
  di- 
  

   chotomy. 
  It 
  is 
  quite 
  evident, 
  that 
  it 
  was 
  fanlike 
  and 
  

   not 
  funnel-shaped; 
  for 
  all 
  the 
  reiterated 
  divisions 
  are 
  to 
  be 
  

   seen 
  on 
  almost 
  every 
  specimen; 
  in 
  evidence 
  of 
  this 
  opinion 
  

   may 
  be 
  adduced 
  the 
  circumstance, 
  that 
  neither 
  of 
  the 
  lateral 
  

   branches 
  on 
  their 
  outer 
  margin 
  are 
  provided 
  vs^ith 
  horizontal 
  

   chitinous 
  filaments. 
  These 
  horizontal 
  threads 
  having 
  served 
  to 
  

   hold 
  the 
  branches 
  apart, 
  have 
  thus 
  acted 
  as 
  a 
  mechanical 
  

   element, 
  in 
  the 
  same 
  manner 
  as 
  the 
  virgula 
  of 
  the 
  Mhabdophora. 
  

  

  To 
  separate 
  those 
  forms 
  from 
  each 
  other 
  which 
  have 
  a 
  

   different 
  number 
  of 
  horizontal 
  filaments, 
  as 
  species 
  or 
  even 
  

   as 
  varieties, 
  seems 
  to 
  be 
  erroneons, 
  their 
  niimber 
  even 
  on 
  

   the 
  same 
  specimen 
  being 
  variable. 
  

  

  This 
  species 
  has 
  attained 
  a 
  considerable 
  size, 
  individuals 
  

   of 
  15 
  — 
  20 
  ctm, 
  in 
  length 
  being 
  often 
  found. 
  Yet 
  at 
  some 
  

   horizons 
  the 
  specimens 
  are 
  commonly 
  small. 
  The 
  individuals 
  

   have 
  lived 
  sociably 
  together, 
  of 
  which 
  the 
  shales 
  of 
  the 
  

   youngest 
  Scandinavian 
  Cambrian 
  rocks 
  covered 
  with 
  their 
  

   polyparies 
  afford 
  evident 
  proofs. 
  

  

  This 
  species 
  occurs 
  always 
  at 
  a 
  fixed 
  horizon, 
  namely 
  in 
  onc 
  

   of 
  the 
  yoimgest 
  beds 
  of 
  the 
  Cambrian 
  system, 
  which 
  is 
  named 
  

   the 
  Dictyonema-shale. 
  At 
  the 
  same 
  level 
  it 
  is 
  represented 
  

   in 
  Estland 
  ; 
  the 
  Graptopora 
  socialis 
  Salter 
  (Muechison, 
  Si- 
  

   luria, 
  Ed. 
  2 
  and 
  3, 
  p. 
  47. 
  Fossils 
  7, 
  fig. 
  3), 
  which 
  occurs 
  in 
  

   the 
  upper 
  part 
  of 
  the 
  Lingula-flags 
  in 
  England, 
  cannot 
  with 
  

   certainty 
  be 
  idcntified 
  with 
  our 
  form 
  ; 
  the 
  indifferent 
  figure 
  

   in 
  Siluria 
  precludes 
  anv 
  certain 
  conclusion. 
  

  

  D. 
  Jiabelliforme 
  occurs 
  at 
  Berg 
  (Hisinger's 
  type 
  specimen), 
  

   at 
  Aby, 
  and 
  other 
  localities 
  in 
  Ostrogothia 
  ; 
  at 
  Orrholmen 
  in 
  

   Vestrogothia 
  ; 
  in 
  Scania 
  at 
  Andrarum, 
  Kiviks-Esperöd, 
  Gislöf, 
  

   Flagabro, 
  Jerrestad, 
  Sandby 
  at 
  the 
  Fågelsångs-river 
  ; 
  at 
  the 
  last 
  

   named 
  place 
  the 
  Dictyoneraa-shales 
  are 
  superimposed 
  by 
  alum 
  

   schist 
  and 
  balls 
  of 
  anthraconite 
  with 
  Åcerocare 
  ecorne 
  Ang. 
  — 
  

   It 
  is 
  moreover 
  to 
  be 
  found 
  on 
  Bornholm 
  and 
  in 
  Norway; 
  in 
  

   Estland; 
  in 
  Belgium 
  and 
  probably 
  also 
  in 
  Great 
  Britain. 
  

  

  This 
  fossil, 
  which 
  unquestionably 
  belongs 
  to 
  the 
  family 
  

   of 
  the 
  Graptolites, 
  was 
  considered 
  by 
  Göppert 
  to 
  be 
  a 
  plant; 
  

   the 
  evidence 
  for 
  this 
  opinion 
  was 
  that 
  he 
  had 
  observed 
  on 
  a 
  

   slab, 
  derived 
  from 
  Estland, 
  a 
  conformation, 
  which 
  he 
  inter- 
  

   preted 
  as 
  a 
  fruit. 
  

  

  