﻿BURNE 
  : 
  ON 
  THE 
  AWATOMY 
  OF 
  RHYSOTA 
  FOULLIOYI. 
  209 
  

  

  distance 
  beneath 
  the 
  right 
  half 
  of 
  the 
  left 
  lobe. 
  The 
  left 
  lobe 
  is 
  

   completely 
  divided 
  into 
  two 
  parts, 
  the 
  left 
  of 
  which 
  is 
  considerably 
  

   produced 
  at 
  its 
  right 
  end. 
  

  

  I'he 
  Mantle- 
  cavity 
  . 
  

  

  The 
  kidney, 
  pericardium, 
  ureter, 
  and 
  rectum 
  occupy 
  the 
  usual 
  

   positions. 
  The 
  kidney 
  (fig. 
  6) 
  is 
  long 
  and 
  narrow, 
  more 
  than 
  twice 
  

   as 
  long 
  as 
  the 
  pericardium. 
  Its 
  cardiac 
  end 
  is 
  to 
  some 
  extent 
  

   broadened 
  out 
  upon 
  the 
  pericardium. 
  The 
  plan 
  of 
  venation 
  of 
  the 
  

   lung-sac 
  is 
  shown 
  in 
  fig. 
  6. 
  

  

  Tlie 
  ureter 
  opens 
  by 
  a 
  minute 
  pore 
  just 
  above 
  the 
  anus, 
  and 
  a 
  groove 
  

   leads 
  the 
  excretion 
  to 
  the 
  right 
  to 
  a 
  cleft 
  in 
  the 
  lower 
  margin 
  of 
  the 
  

   concave 
  surface 
  of 
  the 
  visceral 
  hump, 
  thus 
  away 
  from 
  the 
  respiratory 
  

   orifice. 
  

  

  The 
  Internal 
  Organs. 
  

  

  Upon 
  cutting 
  open 
  the 
  body 
  from 
  above, 
  the 
  organs 
  when 
  slightly 
  

   pushed 
  to 
  the 
  right 
  and 
  left 
  have 
  the 
  appearance 
  shown 
  in 
  fig. 
  4. 
  

  

  21ie 
  Alimentary 
  Canal. 
  Figs. 
  4, 
  4.a. 
  

  

  The 
  jaw 
  was 
  unfortunately 
  not 
  seen. 
  

  

  The 
  buccal 
  mass 
  is 
  small, 
  oval 
  in 
  shape 
  from 
  above, 
  concave 
  in 
  

   profile 
  below, 
  and 
  without 
  a 
  prominent 
  radula-sac. 
  

  

  The 
  oesophagus 
  is 
  narrow, 
  though 
  definitely 
  sacculated 
  below. 
  It 
  

   enlarges 
  with 
  some 
  suddenness 
  to 
  form 
  a 
  voluminous 
  crop, 
  which 
  

   passes 
  without 
  much 
  diminution 
  in 
  calibre 
  into 
  the 
  stomach. 
  The 
  

   stomach, 
  shortly 
  after 
  receiving 
  the 
  bile-duct, 
  is 
  refl.ected 
  on 
  itself 
  at 
  

   the 
  extreme 
  end 
  of 
  the 
  visceral 
  hump 
  to 
  form 
  the 
  first 
  part 
  of 
  the 
  

   intestine, 
  which 
  passes 
  forward 
  beneath 
  the 
  hinder 
  extremity 
  of 
  the 
  

   crop, 
  makes 
  two 
  loops 
  among 
  the 
  liver 
  lobes, 
  and 
  reaches 
  the 
  anus 
  

   along 
  the 
  right 
  side 
  of 
  the 
  mantle-cavity 
  in 
  the 
  usual 
  way. 
  

  

  The 
  salivary 
  glands 
  are 
  united 
  to 
  form 
  a 
  thin 
  sheet 
  upon 
  the 
  dorsal 
  

   surface 
  of 
  the 
  crop. 
  Their 
  ducts 
  enter 
  the 
  buccal 
  cavity 
  in 
  the 
  usual 
  

   position 
  on 
  either 
  side 
  of 
  the 
  origin 
  of 
  the 
  oesophagus. 
  

  

  The 
  radula 
  (fig. 
  8) 
  consists 
  of 
  some 
  189 
  teeth 
  in 
  the 
  transverse 
  row 
  

   (94 
  : 
  1 
  : 
  94). 
  Both 
  median 
  and 
  lateral 
  teeth 
  are 
  monocuspid, 
  tliose 
  

   towards 
  the 
  margins 
  forming 
  simple 
  needle-like 
  hooks. 
  Tlie 
  rows 
  are 
  

   nearly 
  sti-aight 
  from 
  side 
  to 
  side, 
  with 
  the 
  least 
  possible 
  angle 
  at 
  the 
  

   centre. 
  

  

  The 
  Generative 
  Organs. 
  Figs. 
  4, 
  5, 
  ba. 
  

  

  The 
  genital 
  pore 
  lies 
  close 
  below 
  the 
  optic 
  tentacle. 
  It 
  leads 
  into 
  

   a 
  long 
  cylindrical 
  and 
  highly 
  muscular 
  vestibule 
  (CL.) 
  common 
  to 
  

   the 
  openings 
  of 
  the 
  penis 
  and 
  vagina. 
  In 
  the 
  natural 
  position 
  the 
  

   male 
  organs 
  lie 
  to 
  the 
  left, 
  the 
  female 
  and 
  hermaphrodite 
  organs 
  

   to 
  the 
  right. 
  The 
  female 
  consist 
  of 
  a 
  vagina, 
  receptaculum 
  seminis, 
  

   and 
  oviduct 
  ; 
  the 
  male 
  of 
  a 
  penis, 
  epiphallus, 
  kalk-sac, 
  and 
  vas 
  

   deferens. 
  

  

  The 
  vagina 
  opens 
  into 
  the 
  apex 
  of 
  the 
  vestibule. 
  It 
  is 
  a 
  globular 
  

   chamber 
  communicating 
  at 
  its 
  apex 
  with 
  a 
  long 
  thin-walled 
  and 
  

   bluntly 
  pointed 
  receptaculum 
  seminis, 
  and 
  through 
  an 
  aperture 
  in 
  

  

  