﻿48 
  W. 
  B. 
  EANDLES. 
  

  

  pericardial 
  canal 
  does 
  not 
  open 
  directly 
  into 
  tlie 
  kidney, 
  but 
  

   into 
  the 
  genital 
  duct 
  at 
  tlie 
  point 
  where 
  it 
  debouches 
  into 
  the 
  

   urinary 
  chamber. 
  In 
  some 
  of 
  the 
  females 
  tluat 
  were 
  obtained 
  

   during 
  the 
  breeding 
  season 
  ova 
  were 
  found 
  inside 
  the 
  peri- 
  

   cardium, 
  thus 
  demonstrating 
  the 
  existence 
  of 
  a 
  direct 
  com- 
  

   munication 
  between 
  the 
  pericardium 
  and 
  either 
  the 
  genital 
  

   duct 
  or 
  the 
  urinary 
  chamber. 
  Fleure 
  (16) 
  has 
  recently 
  

   described 
  the 
  existence 
  of 
  a 
  right 
  reuo-pericardial 
  pore 
  in 
  

   Haliotis, 
  and 
  mentions 
  the 
  fact 
  that 
  ova 
  were 
  frequently 
  

   found 
  in 
  the 
  pericardium, 
  having 
  been 
  introduced 
  into 
  that 
  

   chamber 
  via 
  the 
  reno-pericardial 
  channel. 
  

  

  The 
  structure 
  of 
  the 
  glandular 
  portion 
  of 
  the 
  right 
  kidney 
  

   has 
  been 
  described 
  by 
  Pcrrier 
  (37) 
  as 
  consisting 
  of 
  a 
  sac 
  

   divided 
  by 
  numerous 
  trabccula?, 
  these 
  being 
  lined 
  with 
  glan- 
  

   dular 
  cells. 
  Haller 
  (21) 
  and 
  Pelseneer 
  (36, 
  p. 
  53) 
  regard 
  it 
  

   rather 
  as 
  a 
  gland 
  composed 
  of 
  a 
  number 
  of 
  acini, 
  the 
  cavities 
  

   of 
  the 
  acini 
  uniting 
  into 
  principal 
  branches, 
  which 
  lead 
  into 
  

   tlie 
  urinary 
  chamber. 
  This, 
  according 
  to 
  my 
  observations, 
  

   appears 
  to 
  be 
  the 
  true 
  intei-pretation 
  of 
  the 
  structure 
  of 
  this 
  

   kidney. 
  The 
  excretory 
  cells 
  (fig. 
  37) 
  are 
  pear-shaped 
  bodies 
  

   with 
  very 
  large 
  nuclei 
  and 
  very 
  granular 
  protoplasm, 
  in 
  

   which 
  are 
  embedded 
  large 
  round 
  granules 
  of 
  a 
  greenish 
  

   colour, 
  evidently 
  products 
  ot" 
  excretion. 
  The 
  ciliated 
  cells 
  

   (fig. 
  37) 
  lining 
  the 
  main 
  passages 
  of 
  the 
  acini 
  and 
  the 
  iirinary 
  

   chamber 
  are 
  much 
  smaller 
  than 
  the 
  true 
  excretory 
  cells, 
  the 
  

   protoplasm 
  is 
  not 
  so 
  granular, 
  and 
  they 
  rarely 
  if 
  ever 
  con- 
  

   tain 
  any 
  excretory 
  granules. 
  

  

  Genital 
  Organs. 
  — 
  The 
  genital 
  gland 
  (figs. 
  39, 
  40, 
  y.y.) 
  is 
  

   in 
  both 
  sexes 
  situated 
  external 
  to 
  the 
  liver, 
  and 
  extends 
  up 
  

   to 
  the 
  termination 
  of 
  the 
  spire 
  of 
  the 
  visceral 
  mass. 
  A 
  

   difference 
  of 
  colour 
  in 
  this 
  gland 
  is 
  ahuost 
  the 
  only 
  character 
  

   by 
  means 
  of 
  wliich 
  the 
  male 
  can 
  be 
  distinguished 
  from 
  the 
  

   female. 
  

  

  In 
  T. 
  lineatus 
  the 
  male 
  gonad 
  is 
  pink, 
  while 
  that 
  of 
  the 
  

   female 
  is 
  green 
  in 
  colour. 
  In 
  both 
  sexes 
  the 
  genital 
  products 
  

   are 
  discharged 
  through 
  a 
  genital 
  duct 
  (figs. 
  35, 
  36, 
  y. 
  d.) 
  into 
  

   tlie 
  urinai-y 
  chamber 
  of 
  the 
  right 
  kidney. 
  This 
  duct 
  was 
  first 
  

  

  