﻿18 
  S. 
  A. 
  TULLBERG, 
  GRAPTOLITES 
  DESCRIBED 
  BY 
  HISINGER. 
  

  

  »Fig. 
  4. 
  Prionotus 
  teretiuscuhis 
  (Nob.) 
  a 
  ceteris 
  Prionoti 
  

   speciebus 
  forma 
  sua 
  teretiuscula 
  optime 
  distinguitiu'. 
  Loc. 
  

   Ocurrit 
  rarius 
  in 
  Schisto 
  argillaceo 
  ad 
  Fågelsång 
  cum 
  Prio- 
  

   noto 
  sagittario 
  et 
  Pr. 
  gemino». 
  

  

  HisiNGER 
  does 
  not 
  give 
  any 
  peculiar 
  character 
  for 
  this 
  

   species; 
  but 
  his 
  type 
  specimen 
  shows 
  clearly 
  to 
  wliich 
  of 
  

   tbe 
  graptolites 
  preserved 
  in 
  full 
  relief 
  and 
  occurring 
  at 
  the 
  

   said 
  locality, 
  he 
  is 
  especially 
  nlluding. 
  On 
  Plate 
  2 
  I 
  hava 
  

   given 
  a 
  new 
  figure 
  of 
  his 
  type 
  specimen, 
  and 
  also 
  several 
  

   fio-ures 
  of 
  this 
  species, 
  partly 
  of 
  flattened 
  specimens, 
  partly 
  

   of 
  examples 
  preserved 
  in 
  relief. 
  

  

  Diplograptus 
  teretiusculus. 
  His. 
  

  

  Plate 
  II, 
  fig. 
  1—7. 
  

  

  DlplocirapUis 
  dentatm 
  Brongn., 
  Läpworth 
  and 
  HoPKiNSON, 
  On 
  the 
  

   Graptolites 
  of 
  the 
  Arenig 
  ' 
  and 
  Llandeilo 
  Rocks 
  of 
  St. 
  Davids. 
  Quart. 
  

   Journ. 
  Geol. 
  Soc, 
  1875, 
  ,p. 
  656, 
  pl. 
  XXXIV, 
  fig. 
  5. 
  — 
  Ngn 
  Biplogr. 
  tere- 
  

   tiusculus 
  TÖRNQ0IST, 
  Geologiska 
  Iakttagelser 
  öfver 
  Fågelsångstraktens 
  

   undersil. 
  lager. 
  Lund 
  1865. 
  

  

  Hydrosoma 
  divided 
  in 
  two 
  parts 
  by 
  a 
  septum, 
  in 
  the 
  

   middle 
  of 
  which 
  the 
  virgula 
  is 
  situated, 
  its 
  length 
  amoim- 
  

   ting 
  to 
  8 
  — 
  10 
  ctm., 
  its 
  breadth 
  to 
  o 
  mm., 
  the 
  ventral 
  margins 
  

   almost 
  parallel, 
  somewhat 
  converging 
  downwards; 
  the 
  proxi- 
  

   mal 
  extremity 
  is 
  rounded, 
  furnished 
  with 
  a 
  long 
  and 
  narrow 
  

   radicle, 
  the 
  virgula 
  is 
  distally 
  prolonged, 
  narrow; 
  hydro- 
  

   thecae 
  9 
  to 
  10 
  mm., 
  inclined 
  to 
  the 
  median 
  line 
  at 
  an 
  angle 
  

   of 
  22°; 
  on 
  the 
  specimens 
  preserved 
  in 
  relief, 
  the 
  hydrothecae 
  

   resemble 
  tubes, 
  their 
  outer 
  margin 
  is 
  concave 
  below, 
  where 
  

   the 
  lower 
  hydrothecae 
  are 
  in 
  contact; 
  the 
  upper 
  free 
  part 
  

   of 
  the 
  outer 
  margin 
  is 
  convex; 
  the 
  inner 
  börder 
  shows 
  

   above 
  a 
  concavity, 
  by 
  which 
  the 
  hydrothecae 
  become 
  somewhat 
  

   tumid. 
  Only 
  on 
  specimens, 
  preserved 
  in 
  natural 
  form, 
  are 
  

   there 
  impressions 
  to 
  be 
  seen, 
  indicating 
  the 
  separating 
  in- 
  

   teriör 
  walls, 
  which 
  continue 
  inwards 
  to 
  the 
  common 
  canal. 
  

   The 
  flattened 
  examples 
  are 
  preserved 
  in 
  many 
  dilFerent 
  ways 
  

   and 
  deviate 
  considerably 
  in 
  appearance 
  from 
  those 
  which 
  have 
  

   preserved 
  their 
  natural 
  shape. 
  

  

  The 
  individuals 
  preserved 
  in 
  relief 
  — 
  Hisingee's 
  type 
  

   specimen 
  is 
  such 
  a 
  one 
  — 
  have 
  a 
  highly 
  characteristic 
  appea- 
  

   rance 
  ; 
  they 
  are 
  very 
  similar 
  to 
  I), 
  putillas 
  Hall. 
  The 
  träns- 
  

  

  