﻿WATSON: 
  NOTES 
  ON 
  HTGR03IIA 
  LIMBATA 
  (dRAP.). 
  125 
  

  

  the 
  middle. 
  The 
  lower 
  half 
  of 
  the 
  jaw 
  is 
  finely 
  striate 
  along 
  the 
  

   lines 
  of 
  growth, 
  and 
  very 
  delicate 
  vertical 
  striae 
  are 
  also 
  present. 
  

  

  The 
  radula 
  (pi. 
  Ill, 
  iig. 
  29) 
  measures 
  about 
  HxS^mm. 
  when 
  

   flattened 
  out. 
  The 
  central 
  tooth 
  in 
  each 
  row 
  has 
  a 
  prominent 
  but 
  

   rather 
  short 
  mesocone, 
  flanked 
  by 
  a 
  pair 
  of 
  very 
  low, 
  scarcely 
  

   developed 
  ectocones. 
  In 
  the 
  inner 
  lateral 
  teeth 
  the 
  ectocones 
  are 
  

   also 
  very 
  poorly 
  developed, 
  but 
  after 
  about 
  the 
  eighth 
  tooth 
  on 
  each 
  

   side 
  they 
  gradually 
  become 
  more 
  prominent 
  and 
  more 
  distinctly 
  

   separate 
  from 
  the 
  mesocones. 
  In 
  the 
  outer 
  marginal 
  teeth 
  the 
  

   ectocones 
  are 
  divided 
  into 
  two, 
  or 
  occasionally 
  more, 
  distinct 
  cusps. 
  

   The 
  endocones 
  of 
  the 
  lateral 
  teeth 
  are 
  represented 
  by 
  meie 
  flanges 
  

   along 
  the 
  inner 
  edges 
  of 
  the 
  mesocones, 
  but 
  in 
  the 
  marginal 
  teeth 
  

   these 
  become 
  partially 
  separated 
  from 
  the 
  mesocones, 
  acquiring 
  

   points 
  of 
  their 
  own 
  — 
  points 
  which 
  in 
  some 
  cases 
  may 
  be 
  split 
  into 
  

   two 
  or 
  even 
  three 
  denticles 
  — 
  although 
  towards 
  their 
  bases 
  they 
  

   remain 
  united 
  with 
  the 
  mesocones. 
  Indeed, 
  it 
  would 
  perha})s 
  

   be 
  more 
  correct 
  to 
  say 
  that 
  no 
  true 
  endocones 
  are 
  developed, 
  but 
  

   that 
  the 
  mesocones 
  of 
  the 
  marginal 
  teeth 
  are 
  bifid. 
  The 
  lateral 
  

   and 
  marginal 
  teeth 
  ate 
  about 
  equal 
  in 
  number, 
  but 
  the 
  transition 
  

   from 
  one 
  type 
  to 
  the 
  other 
  is 
  very 
  gradual. 
  The 
  basal 
  plates 
  are 
  

   of 
  the 
  usual 
  quadrate 
  form 
  ; 
  they 
  are 
  longer 
  than 
  broad 
  towards 
  the 
  

   centre 
  of 
  the 
  radula, 
  but 
  very 
  much 
  broader 
  than 
  long 
  towards 
  

   the 
  margins. 
  The 
  transverse 
  rows 
  of 
  teeth 
  are 
  not 
  quite 
  straight, 
  

   but 
  curve 
  forwards 
  towards 
  the 
  edges 
  on 
  both 
  sides. 
  The 
  formula 
  of 
  

   the 
  Devonshire 
  specimen 
  is 
  (14 
  + 
  14 
  + 
  1 
  + 
  14 
  + 
  15) 
  x 
  114. 
  

  

  In 
  a 
  specimen 
  from 
  Argeles, 
  Hautes-Pyrenees, 
  the 
  teeth 
  are 
  of 
  

   almost 
  exactly 
  the 
  same 
  shape, 
  but 
  they 
  are 
  more 
  numerous, 
  there 
  

   being 
  a 
  larger 
  number 
  of 
  marginal 
  teeth 
  and 
  of 
  transverse 
  rows. 
  

   The 
  formula 
  of 
  this 
  specimen 
  is 
  (19 
  + 
  13 
  + 
  1 
  + 
  12 
  + 
  20) 
  x 
  135. 
  On 
  

   the 
  other 
  hand, 
  in 
  an 
  example 
  from 
  Pan, 
  Basses-Pyrenees, 
  while 
  the 
  

   radula 
  resembles 
  the 
  Devonshire 
  one 
  more 
  closely 
  as 
  regards 
  

   the 
  number 
  of 
  the 
  teeth, 
  the 
  formula 
  being 
  (17+14 
  + 
  1 
  + 
  13 
  + 
  

   18) 
  X 
  107, 
  the 
  shape 
  of 
  the 
  teeth 
  is 
  not 
  so 
  exactly 
  similar, 
  the 
  

   central 
  and 
  inner 
  lateral 
  teeth 
  being 
  slightly 
  longer 
  and 
  narrower, 
  

   with 
  scarcely 
  any 
  traces 
  of 
  the 
  ectocones. 
  

  

  The 
  radula-sac 
  projects 
  considerably 
  from 
  the 
  hind 
  end 
  of 
  the 
  

   buccal 
  mass, 
  and 
  is 
  abruptly 
  curved 
  upwards. 
  

  

  The 
  CEsophagus 
  shows 
  two 
  or 
  three 
  longitudinal 
  lines 
  of 
  dark 
  

   pigment. 
  In 
  the 
  specimens 
  examined 
  it 
  was 
  not 
  dilated 
  to 
  form 
  

   a 
  distinct 
  crop, 
  but 
  passed 
  straight 
  back 
  into 
  the 
  rather 
  long 
  stomach 
  

   (pi. 
  II, 
  fig. 
  10). 
  From 
  the 
  other 
  end 
  of 
  the 
  stomach 
  the 
  intestine 
  

   passes 
  forwards, 
  and 
  then 
  bends 
  back 
  again, 
  describing 
  the 
  usual 
  

   S-shaped 
  curve, 
  before 
  finally 
  passing 
  forwards 
  as 
  the 
  rectum. 
  

  

  The 
  salivary 
  glands 
  are 
  rather 
  long 
  and 
  narrow, 
  and 
  are 
  united 
  to 
  

   each 
  other 
  above 
  the 
  oesophagus 
  excepting 
  at 
  their 
  front 
  ends, 
  where 
  

   the 
  salivary 
  ducts 
  emerge 
  from 
  the 
  glandular 
  tissue. 
  

  

  The 
  liver 
  consists 
  as 
  usual 
  of 
  two 
  divisions, 
  discharging 
  into 
  the 
  

   stomach 
  by 
  separate 
  hepatic 
  ducts. 
  The 
  posterior 
  occupies 
  the 
  upper 
  

   whorls 
  of 
  the 
  spire, 
  while 
  the 
  anterior 
  lies 
  among 
  the 
  loops 
  of 
  the 
  

   intestine, 
  which 
  divide 
  it 
  into 
  three 
  main 
  lobes, 
  one 
  behind 
  another. 
  

  

  