﻿BIHANG 
  TILL 
  K. 
  SV. 
  VET.-AKAD. 
  HANDL. 
  BAND. 
  fi. 
  N:0 
  13. 
  19 
  

  

  verse 
  section 
  of 
  the 
  hydrosoma 
  is 
  rounded-elliptic; 
  the 
  distance 
  

   from 
  one 
  series 
  of 
  hydrothecac 
  to 
  the 
  otlier 
  is 
  very 
  great; 
  

   the 
  middle 
  of 
  the 
  hydrosoma 
  is 
  distinguished 
  by 
  a 
  vertical 
  

   impressed 
  line, 
  marking 
  the 
  place 
  of 
  the 
  septum; 
  the 
  free 
  

   part 
  of 
  the 
  hydrothecae 
  is 
  short, 
  and 
  their 
  outer 
  margin 
  sho.rt 
  

   and 
  curved. 
  The 
  aperture 
  seems 
  to 
  be 
  wide 
  ; 
  the 
  apertural- 
  

   margin 
  is 
  obliquely 
  inclined 
  to 
  the 
  axis. 
  Specimens 
  of 
  this 
  

   kind 
  also 
  show 
  an 
  impressed 
  line, 
  passing 
  from 
  the 
  innerwall 
  

   of 
  the 
  theca 
  downwards 
  to 
  the 
  middle 
  of 
  the 
  hydrosoma, 
  

   which 
  indicates 
  the 
  existence 
  of 
  separating 
  innerwalls. 
  

  

  Compressed 
  examples 
  deviate 
  in 
  appearance 
  very 
  rauch 
  

   from 
  those 
  last 
  described; 
  they 
  present 
  many 
  different 
  aspects, 
  

   owing 
  to 
  the 
  position 
  in 
  which 
  the 
  hydrosoma 
  is 
  preserved 
  ; 
  

   commonly 
  they 
  remind 
  us 
  most 
  of 
  the 
  Diplograptus 
  foliaceus 
  

   MuRCH., 
  sometimes 
  of 
  D. 
  quadrinmcronatus 
  Hall. 
  or 
  even 
  

   D. 
  pristis 
  His. 
  Several 
  specimens 
  thus 
  preserved 
  in 
  diiferent 
  

   ways 
  are 
  represented 
  on 
  Plate 
  II, 
  fig. 
  4 
  — 
  7. 
  

  

  Transitional 
  forms 
  fossilized 
  in 
  semi-relief 
  show 
  clearly, 
  

   that 
  these 
  individuals 
  so 
  different 
  in 
  aspect 
  belong 
  to 
  one 
  

   and 
  the 
  same 
  species. 
  

  

  This 
  species 
  occurs 
  in 
  great 
  abundance 
  at 
  Fågelsång, 
  in 
  

   the 
  zone 
  of 
  Didymograptus 
  geminus, 
  in 
  the 
  zone 
  of 
  Glosso- 
  

   graptus, 
  in 
  the 
  zone 
  of 
  Gymnograptus, 
  and 
  the 
  superjacent 
  

   shale. 
  These 
  strata 
  belong, 
  no 
  doubt, 
  to 
  the 
  Llandeilo-beds. 
  

  

  The 
  figures 
  and 
  the 
  description, 
  which 
  Lapworth 
  gives 
  

   of 
  a 
  species, 
  which 
  he 
  calls 
  Diplograptus 
  dentatus 
  Brongn., 
  

   (1. 
  c.) 
  agree 
  very 
  well 
  with 
  flattened 
  specimens 
  of 
  this 
  spe- 
  

   cies; 
  yet 
  this 
  is 
  said 
  to 
  occur 
  in 
  Wales 
  in 
  strata 
  of 
  upper 
  

   Arenig-age; 
  but 
  JD. 
  teretiusculus 
  appears 
  at 
  first 
  in 
  strata, 
  that 
  

   cannot 
  be 
  older 
  than 
  the 
  Llandeilo. 
  Moreover 
  there 
  is 
  no 
  

   sufficient 
  evidence 
  that 
  the 
  denomination 
  given 
  by 
  Brongniart 
  

   ought 
  to 
  be 
  employed 
  for 
  this 
  form. 
  

  

  No. 
  8. 
  Finally 
  Hisinger 
  has 
  in 
  Supplement 
  imi 
  secundum 
  

   Tab. 
  XXXVIII 
  given 
  the 
  figure 
  of 
  a 
  fossil 
  also 
  belonging 
  

   to 
  the 
  family 
  of 
  the 
  Graptolites. 
  

  

  »Fig. 
  9. 
  Impressio 
  Plantae 
  Monocotyledoneae, 
  Loc. 
  In 
  

   schisto 
  aluminaceo 
  ad 
  Berg, 
  Ostrogothiae». 
  

  

  