﻿126 
  PUOCKEDINGS 
  OF 
  THE 
  MALACOLOGICAL 
  SOCIETY. 
  

  

  The 
  most 
  posterior 
  of 
  these 
  lobes, 
  however, 
  sends 
  forward 
  a 
  narrow 
  

   proloiigatiou 
  close 
  to 
  the 
  last 
  portion 
  of 
  the 
  intestine. 
  

  

  Muscular 
  Systkm. 
  — 
  The 
  columellar 
  muscle 
  divides 
  not 
  far 
  from 
  its 
  

   origin 
  into 
  three 
  main 
  divisions 
  lying 
  one 
  above 
  another 
  (pi. 
  II, 
  

   tig. 
  3). 
  The 
  most 
  dorsal 
  division 
  is 
  the 
  powerful 
  buccal 
  retractor, 
  

   which 
  bifurcates 
  just 
  before 
  it 
  reaches 
  the 
  buccal 
  mass, 
  and 
  is 
  

   inserted 
  low 
  down 
  on 
  each 
  side 
  of 
  the 
  hind 
  end 
  of 
  that 
  organ. 
  Below 
  

   this 
  another 
  broad 
  muscle 
  runs 
  forward 
  and 
  eventually 
  divides 
  into 
  

   a 
  right 
  and 
  a 
  left 
  portion. 
  Each 
  of 
  these 
  portions 
  then 
  gives 
  off 
  the 
  

   retractors 
  of 
  the 
  upper 
  and 
  lower 
  tentacles 
  of 
  that 
  side, 
  and 
  gradually 
  

   breaks 
  up 
  into 
  numerous 
  narrow 
  muscles 
  inserted 
  in 
  the 
  anterior 
  end 
  

   of 
  the 
  foot. 
  The 
  retractor 
  of 
  the 
  right 
  upper 
  tentacle 
  passes 
  

   between 
  the 
  penis 
  and 
  the 
  vagina. 
  The 
  lowest 
  division 
  of 
  the 
  

   c.)lumellar 
  muscle 
  does 
  not 
  become 
  subdivided, 
  but 
  forms 
  the 
  so-called 
  

   tail 
  retractor, 
  being 
  inserted 
  in 
  the 
  posterior 
  part 
  of 
  the 
  foot. 
  

  

  The 
  penial 
  retractor 
  arises 
  towards 
  the 
  front 
  end 
  of 
  the 
  diaphragm 
  

   and 
  unites 
  with 
  tlie 
  epiphallus 
  about 
  3"5 
  mm. 
  behind 
  the 
  junction 
  of 
  

   that 
  organ 
  with 
  the 
  penis. 
  Other 
  slender 
  muscles 
  arise 
  from 
  tlie 
  

   anterior 
  part 
  of 
  the 
  epiphallus, 
  a 
  little 
  further 
  forward 
  than 
  the 
  

   insertion 
  of 
  the 
  penial 
  retracto?', 
  and 
  pass 
  across 
  to 
  the 
  genital 
  atrium 
  

   (pl. 
  II, 
  fig. 
  7). 
  

  

  Reproductive 
  Organs. 
  (PI. 
  11, 
  fig. 
  7.) 
  — 
  The 
  hermaphrodite 
  gland 
  

   or 
  ovotestis 
  is 
  embedded 
  in 
  the 
  posterior 
  division 
  of 
  the 
  liver, 
  and 
  

   consists 
  of 
  numerous 
  small 
  oval 
  follicles 
  arranged 
  in 
  about 
  four 
  

   clusters, 
  which, 
  however, 
  are 
  not 
  widely 
  separated 
  from 
  one 
  another. 
  

   The 
  hermaphrodite 
  duct 
  is 
  swollen 
  and 
  much 
  convoluted, 
  except 
  

   towards 
  its 
  ends. 
  As 
  it 
  approaches 
  the 
  common 
  duct 
  it 
  tuins 
  

   abruptly 
  backwards, 
  and 
  then 
  bends 
  forwards 
  again 
  close 
  to 
  the 
  

   albumen 
  gland, 
  being 
  enlarged 
  at 
  the 
  second 
  angle 
  to 
  form 
  a 
  vesicula 
  

   serainalis. 
  The 
  albumen 
  gland 
  and 
  the 
  common 
  duct 
  are 
  of 
  the 
  

   usual 
  form, 
  the 
  latter 
  organ 
  being 
  sharply 
  divided 
  into 
  the 
  opaque 
  

   male 
  portion 
  and 
  the 
  female 
  portion 
  with 
  translucent 
  folded 
  walls. 
  

   The 
  free 
  oviduct 
  is 
  rather 
  short 
  and 
  narrow. 
  Instead 
  of 
  there 
  being 
  

   a, 
  globular 
  receptaculum 
  seminis 
  borne 
  on 
  a 
  slender 
  duct, 
  the 
  

   spermatheca 
  takes 
  the 
  form 
  of 
  a 
  very 
  long 
  uubranched 
  tube, 
  broader 
  

   than 
  the 
  usual 
  receptacular 
  duct 
  and 
  extending 
  back 
  at 
  least 
  as 
  far 
  

   as 
  the 
  albumen 
  gland, 
  but 
  ending 
  blindly 
  without 
  any 
  terminal 
  

   enlargement. 
  

  

  Just 
  in 
  front 
  of 
  the 
  opening 
  of 
  this 
  organ, 
  eight 
  finger-shaped 
  

   mucous 
  glands 
  arise 
  from 
  the 
  vagina 
  ; 
  they 
  are 
  unbranched 
  and 
  

   about 
  3 
  mm. 
  in 
  length. 
  The 
  dart-sac 
  is 
  rather 
  narrow 
  and 
  

   degenerate, 
  and 
  arises 
  a 
  considerable 
  distance 
  in 
  front 
  of 
  the 
  mucous 
  

   glands. 
  It 
  contains 
  a 
  slightly 
  curved 
  liollow 
  calcareous 
  dart, 
  

   expanded 
  at 
  the 
  base, 
  and 
  about 
  3"5mm. 
  long 
  (fig. 
  9). 
  Wedged 
  in 
  

   between 
  the 
  dart-sac 
  and 
  the 
  vagina 
  there 
  is 
  an 
  oval 
  accessory 
  sac 
  ; 
  

   the 
  three 
  organs, 
  however, 
  are 
  closely 
  united 
  with 
  one 
  another, 
  only 
  

   the 
  extreme 
  end 
  of 
  the 
  dart-sac 
  projecting 
  freely. 
  The 
  accessory 
  sac 
  

   opens 
  into 
  the 
  vagina, 
  and 
  has 
  extremely 
  thick 
  and 
  muscular 
  walls. 
  

   Its 
  narrow 
  cavity 
  is 
  at 
  first 
  formed 
  by 
  a 
  mere 
  longitudinal 
  groove 
  

   inside 
  the 
  vagina, 
  but 
  towards 
  the 
  hind 
  end 
  of 
  the 
  accessory 
  sac 
  this 
  

  

  