﻿BIHANG 
  TILL 
  K. 
  SV. 
  VET.-AKAD. 
  HANDL. 
  BAND. 
  6. 
  N:0 
  13. 
  15 
  

  

  No. 
  5. 
  The 
  third 
  Graptolite 
  on 
  tlie 
  slab 
  from 
  Furudal 
  is 
  

   a 
  Ceplialograptus, 
  wliich 
  Hisinger 
  describes 
  in 
  the 
  following 
  

   manner 
  : 
  

  

  »Prionotus 
  folium 
  oblongo-lanceolatus? 
  rectus, 
  duas 
  lineas 
  

   latus, 
  compressus, 
  rachide 
  centrali, 
  capillari, 
  utriuque 
  pinnulis 
  

   angulai 
  acuto 
  exeuntibus, 
  linearibus, 
  acutiusculis, 
  dense 
  incum- 
  

   bentibus. 
  — 
  Icon. 
  Petrif. 
  Suec. 
  Suppl. 
  Tab. 
  XXXV, 
  fig. 
  8 
  a, 
  

   raagn. 
  aat. 
  b, 
  magn. 
  aucta. 
  — 
  Loc. 
  Gum 
  praecedenti. 
  Mus. 
  nostr.» 
  

  

  On 
  the 
  slab 
  there 
  are 
  two 
  complete 
  specimens, 
  and 
  one 
  

   fragment 
  of 
  a 
  larger 
  individual, 
  besides 
  more 
  incomplete 
  

   parts. 
  Hisinger's 
  figure 
  is 
  thus 
  constructed 
  from 
  these 
  spe- 
  

   cimens. 
  His 
  magnified 
  figure 
  has 
  no 
  resemblance 
  to 
  anyone 
  

   of 
  the 
  originals. 
  The 
  figures 
  15, 
  16 
  and 
  17 
  on 
  my 
  first 
  plate 
  

   are 
  figures 
  of 
  the 
  actual 
  specimens 
  from 
  which 
  Hisingek 
  

   composed 
  his 
  figures. 
  

  

  Oephalograptus 
  folium. 
  His. 
  

  

  Plate 
  I, 
  fig. 
  15—19. 
  

  

  Prionotus 
  folium 
  HiS., 
  1. 
  c. 
  — 
  Diplograptus 
  folimn 
  TÖRNQUIST^ 
  Om 
  

   några 
  graptolitarter 
  från 
  Dalarne; 
  1. 
  c. 
  p. 
  442. 
  fig. 
  7. 
  — 
  NON 
  Diplo- 
  

   c/rapUis 
  folium 
  NiCHOLSON 
  nec 
  Harkness. 
  

  

  Seen 
  from 
  the 
  narrow 
  proximal 
  part 
  the 
  hydrosoma 
  

   strongly 
  and 
  continually 
  increases 
  in 
  breadth 
  to 
  about 
  the 
  

   point 
  where 
  the 
  two 
  first 
  hydrothecae 
  cease 
  ; 
  then 
  its 
  veu- 
  

   tral 
  margins 
  are 
  almost 
  parallel; 
  above, 
  it 
  is 
  rounded; 
  its 
  

   length 
  amounts 
  generally 
  to 
  2.5 
  ctm. 
  and 
  its 
  breadth 
  to 
  5 
  

   mm. 
  The 
  virgula 
  is 
  distally 
  elongated, 
  narrow. 
  On 
  10 
  

   mm. 
  there 
  are 
  10 
  hydrothecae, 
  inclined 
  to 
  the 
  axis 
  at 
  an 
  

   angle 
  of 
  5°, 
  which 
  increases 
  to 
  35°; 
  narrow, 
  very 
  long 
  

   tubes, 
  probablv 
  of 
  square 
  section, 
  a 
  little 
  curved 
  ; 
  the 
  apertural 
  

   margin 
  rectangular 
  to 
  the 
  axis 
  of 
  the 
  theca. 
  On 
  some 
  spe- 
  

   cimens 
  the 
  test 
  of 
  the 
  hydrothecae 
  seems 
  to 
  be 
  covered 
  by 
  

   faint, 
  transverse 
  strise, 
  rectangular 
  to 
  the 
  axis 
  of 
  the 
  theca. 
  

  

  This 
  species, 
  which 
  seems 
  to 
  be 
  wholly 
  unknown 
  to 
  

   foreign 
  authors, 
  belongs 
  to 
  a 
  group, 
  consisting 
  onh^ 
  of 
  two 
  

   varieties, 
  which, 
  formerly 
  included 
  in 
  the 
  genus 
  Diplograptus, 
  

   was 
  separated 
  by 
  Hopkinson 
  under 
  the 
  name 
  cited. 
  The 
  re- 
  

   presentative 
  previously 
  known 
  is 
  Ceplialograptus 
  cometa, 
  Gein. 
  

  

  The 
  external 
  form 
  of 
  the 
  two 
  species 
  last 
  mentioned 
  

   is 
  most 
  singular, 
  the 
  hydrosoma 
  rapidly 
  decreasing 
  in 
  size 
  

  

  