﻿622 
  MISS 
  DOXAED 
  OX 
  SOME 
  NEW 
  SPECIES 
  

  

  Section 
  Goniostropha, 
  CEhlert, 
  1888. 
  

  

  Merchisoxia 
  (Goniostropha) 
  terriceeata, 
  De 
  Kon. 
  (PI. 
  XX. 
  

  

  fig. 
  5.) 
  

  

  Murchisonia 
  turriculata, 
  De 
  Koninck, 
  1883, 
  ' 
  Faune 
  du 
  Calcaire 
  

   Carb. 
  de 
  la 
  Belgique,' 
  p. 
  19, 
  pi. 
  xxxiv. 
  figs. 
  11, 
  12, 
  13. 
  

  

  Murchisonia 
  angulata, 
  var., 
  De 
  Koninck, 
  1843, 
  ' 
  Descr. 
  des 
  Anim. 
  

   Foss. 
  du 
  Terr. 
  Carb. 
  de 
  la 
  Belgique,' 
  p. 
  412, 
  pi. 
  xl. 
  fig. 
  8. 
  

  

  A 
  fragment 
  of 
  a 
  shell, 
  consisting 
  of 
  four 
  whorls, 
  seems 
  to 
  agree 
  in 
  

   all 
  essential 
  particulars 
  with 
  one 
  described 
  and 
  figured 
  by 
  De 
  Koninck 
  

   as 
  Murchisonia 
  turriculata. 
  If 
  entire 
  it 
  would 
  be 
  elongated 
  aud 
  com- 
  

   posed 
  of 
  numerous 
  angular 
  whorls. 
  The 
  specimens 
  described 
  by 
  De 
  

   Koninck 
  have 
  from 
  sixteen 
  to 
  eighteen 
  whorls. 
  There 
  is 
  a 
  prominent 
  

   keel 
  about 
  the 
  centre 
  of 
  each 
  whorl, 
  and 
  below 
  it 
  there 
  are 
  two 
  finer 
  

   keels 
  placed 
  at 
  about 
  equal 
  distances 
  from 
  it 
  and 
  from 
  each 
  other 
  ; 
  on 
  

   the 
  lowest 
  whorl 
  preserved 
  there 
  is 
  evidence 
  of 
  a 
  still 
  finer 
  keel 
  appear- 
  

   ing 
  above 
  the 
  suture. 
  De 
  Koninck 
  does 
  not 
  mention 
  the 
  presence 
  

   of 
  this 
  lower 
  keel 
  on 
  his 
  specimens, 
  but 
  there 
  are 
  more 
  numerous 
  

   keels 
  on 
  the 
  shell 
  previously 
  described 
  by 
  him 
  as 
  Murchisonia 
  

   angulata, 
  var., 
  which 
  has 
  since 
  been 
  identified 
  by 
  him 
  with 
  M. 
  

   turriculata. 
  ^And 
  in 
  other 
  instances 
  the 
  number 
  of 
  keels 
  on 
  differ- 
  

   ent 
  individuals 
  of 
  the 
  same 
  species 
  is 
  observed 
  to 
  vary. 
  The 
  presence 
  

   or 
  absence 
  of 
  a 
  keel 
  cannot 
  therefore 
  be 
  considered 
  of 
  much 
  import- 
  

   ance 
  when 
  shells 
  agree 
  in 
  other 
  particulars. 
  On 
  the 
  upper 
  part 
  

   of 
  the 
  whorl 
  there 
  is 
  a 
  much 
  finer 
  keel, 
  placed 
  somewhat 
  nearer 
  to 
  

   the 
  suture 
  than 
  to 
  the 
  central 
  keel. 
  De 
  Koninck 
  says 
  this 
  keel 
  is 
  

   in 
  the 
  middle 
  of 
  the 
  upper 
  part 
  of 
  the 
  whorl 
  in 
  the 
  specimen 
  figured 
  

   by 
  him 
  ; 
  it, 
  however, 
  seems 
  to 
  vary 
  in 
  position 
  on 
  different 
  individuals 
  

   in 
  the 
  Brussels 
  Museum, 
  beiug 
  higher 
  on 
  some 
  and 
  lower 
  on 
  others. 
  

   The 
  surface 
  of 
  the 
  whorls 
  is 
  almost 
  flat 
  both 
  above 
  and 
  below 
  the 
  

   principal 
  keel. 
  The 
  lines 
  of 
  growth 
  are 
  indistinct, 
  so 
  that 
  no 
  

   evidence 
  of 
  the 
  position 
  of 
  the 
  sinus 
  can 
  be 
  obtained 
  from 
  this 
  

   specimen. 
  De 
  Koninck 
  says 
  it 
  is 
  situated 
  between 
  the 
  strongest 
  

   keel 
  and 
  that 
  next 
  below. 
  The 
  mouth 
  is 
  not 
  preserved. 
  De 
  

   Koninck 
  describes 
  that 
  of 
  the 
  Belgian 
  specimens 
  as 
  round. 
  My 
  

   specimen 
  is 
  crushed, 
  so 
  the 
  spiral 
  angle 
  cannot 
  be 
  accurately 
  

   ascertained. 
  

  

  I 
  believe 
  this 
  is 
  the 
  first 
  record 
  of 
  this 
  species 
  being 
  found 
  in 
  

   Britain. 
  

  

  Length 
  of 
  fragment 
  of 
  four 
  whorls 
  10 
  i 
  millim., 
  width 
  of 
  lower 
  

   whorl 
  one 
  way 
  6^ 
  millim.; 
  in 
  the 
  opposite 
  direction 
  4 
  millim. 
  

  

  Locality. 
  Abbey 
  Foss, 
  Askrigg, 
  Yorkshire. 
  

  

  Formation. 
  Shales 
  at 
  the 
  base 
  of 
  the 
  Yoredale 
  rocks. 
  

  

  Merchisonia 
  (Goniostropha) 
  terriceeata, 
  var. 
  scotica. 
  (PI. 
  XX. 
  

   fig. 
  6.) 
  

   A 
  fragment 
  of 
  a 
  shell 
  of 
  which 
  about 
  six 
  gradually 
  increasing 
  whorls 
  

   are 
  preserved 
  seems 
  to 
  agree 
  with 
  that 
  last 
  described 
  except 
  in 
  its 
  

   much 
  smaller 
  size. 
  This 
  difference 
  in 
  size 
  is 
  so 
  great 
  as 
  quite 
  to 
  

   constitute 
  a 
  variety, 
  if 
  not 
  a 
  distinct 
  species. 
  The 
  position 
  and 
  

  

  