﻿436 
  rnocEEDixcs 
  of 
  the 
  national 
  mvsevm. 
  

  

  of 
  first 
  seginent, 
  0.7; 
  bieadtli 
  of 
  liist 
  segiiieut, 
  anterior, 
  0.3; 
  i)OSterior, 
  

   ().()."); 
  length 
  of 
  nnnlian 
  segments, 
  3; 
  l)readtli, 
  3; 
  length 
  of 
  posterior 
  

   segments, 
  1; 
  breadth, 
  1."). 
  

  

  Ova 
  numerons, 
  in 
  elnsters 
  along 
  median 
  line. 
  O.Oaii 
  and 
  0.035 
  mm. 
  in 
  

   two 
  principal 
  diameters. 
  

  

  Thin 
  sections 
  nnide 
  in 
  tiie 
  three 
  ])rincii)al 
  directions 
  reveal 
  the 
  follow- 
  

   ing 
  anatomical 
  details: 
  The 
  rei)r<)dnctive 
  cloaca' 
  lie 
  along 
  the 
  median 
  

   line 
  of 
  one 
  of 
  the 
  flat 
  snrfaces 
  of 
  the 
  body. 
  The 
  external 
  openings 
  of 
  

   the 
  nterns 
  lie 
  along 
  the 
  median 
  line 
  of 
  the 
  opposite 
  surface. 
  The 
  cirrus- 
  ^ 
  

   bull) 
  is 
  very 
  muscular, 
  long 
  pyriform, 
  its 
  inner 
  end 
  deflected 
  to 
  the 
  

   right, 
  where 
  it 
  communicates 
  with 
  the 
  vas 
  deferens, 
  which 
  lies 
  in 
  numer- 
  

   ous 
  folds 
  in 
  front 
  and 
  to 
  the 
  right 
  of 
  the 
  cirrus-bulb. 
  The 
  length 
  of 
  one 
  

   cirrus-bulb 
  to 
  the 
  point 
  of 
  deflection 
  was 
  0.4 
  mm., 
  its 
  greatest 
  diameter 
  

   0.14. 
  The 
  vagina 
  lies 
  immediately 
  behind 
  the 
  cirrus-bulb 
  and 
  follows 
  a 
  

   course 
  parallel 
  to 
  it. 
  Near 
  the 
  external 
  aperture 
  it 
  expands 
  into 
  a 
  uapi- 
  

   form 
  muscular 
  body; 
  in 
  the 
  one 
  measured, 
  0.05 
  mm. 
  in 
  length 
  and 
  0.07 
  

   in 
  transverse 
  diameter. 
  My 
  sections 
  were 
  made 
  from 
  segments 
  already 
  

   nuituie, 
  and 
  the 
  folds 
  of 
  the 
  uterus 
  containing 
  ova 
  occupied 
  a 
  consid- 
  

   erable 
  ])art 
  of 
  the 
  interior, 
  obliterating 
  the 
  commnuication 
  between 
  

   vagina 
  and 
  uterus. 
  Calling 
  that 
  surface 
  ventral 
  which 
  bears 
  the 
  repro- 
  

   ductive 
  apertures, 
  then 
  the 
  apertures 
  of 
  the 
  uterus 
  are 
  along 
  the 
  dorsal 
  

   surface. 
  The 
  uterus 
  near 
  these 
  apertures 
  becomes 
  capacious 
  and 
  is 
  lined 
  

   with 
  cilia. 
  The 
  ovary 
  lies 
  near 
  the 
  dorsal 
  surface 
  and 
  near 
  the 
  posterior 
  

   part 
  of 
  the 
  segment. 
  The 
  segments 
  are 
  not 
  sei)ai-able 
  and 
  not 
  even 
  

   shari)ly 
  outlined. 
  The 
  structure 
  of 
  the 
  body 
  is 
  as 
  follows: 
  Beginning 
  

   with 
  the 
  external 
  layer, 
  (1) 
  cuticle, 
  (2) 
  layer 
  made 
  up 
  of 
  radiating 
  fibers 
  

   with 
  scattered 
  delicate 
  longitudinal 
  fibers, 
  (3) 
  layer 
  of 
  glandular 
  bodies, 
  

   vitellaria, 
  (4) 
  thin 
  layer 
  of 
  circular 
  fibers 
  from 
  which 
  fibers 
  radiate 
  into 
  

   both 
  contiguous 
  layers, 
  (5) 
  layer 
  of 
  strong 
  longitudinal 
  muscle 
  fibers, 
  

   (0) 
  circular 
  layer, 
  (7) 
  central 
  core 
  consisting 
  of 
  transverse 
  fibers, 
  granular 
  

   parenchyma, 
  and 
  containing 
  the 
  testes, 
  

  

  A 
  body 
  which 
  lies 
  about 
  the 
  middle 
  of 
  the 
  posterior 
  edge 
  of 
  each 
  

   segment, 
  behind 
  the 
  vaginal 
  tube 
  and 
  near 
  the 
  ovary, 
  I 
  take 
  to 
  be 
  either 
  

   an 
  enlargement 
  of 
  the 
  vitelline 
  duct 
  or 
  vitelline 
  reservoir, 
  or, 
  in 
  part 
  at 
  

   least, 
  an 
  internal 
  vitelline 
  gland. 
  It 
  has 
  the 
  same 
  appearance 
  in 
  

   stained 
  sections 
  as 
  the 
  glands 
  of 
  the 
  above 
  named 
  third-body 
  layer. 
  

  

  Numerous 
  calcareous 
  bodies 
  with 
  strongly 
  marked 
  concentric 
  struc- 
  

   ture 
  occur 
  in 
  difl'erent 
  i)arts 
  of 
  the 
  segments. 
  They 
  are 
  mostly 
  oval 
  in 
  

   shape. 
  One 
  of 
  the 
  smallest 
  measured 
  0.017 
  mm. 
  in 
  length 
  and 
  0.008 
  m 
  

   breadth; 
  one 
  of 
  the 
  largest 
  was 
  0.024 
  and 
  0.014 
  in 
  the 
  two 
  principal 
  

   diameters. 
  Longitudinal 
  vessels 
  could 
  not 
  be 
  made 
  out 
  in 
  my 
  sections. 
  

   The 
  lacini;e 
  are 
  prolongations 
  of 
  the 
  external 
  cuticular 
  layer 
  and 
  the 
  

   underlying 
  granulo-fibrous 
  layer. 
  In 
  some 
  cases 
  a 
  few 
  of 
  the 
  grandular 
  

   bodies 
  of 
  the 
  third 
  layer 
  were 
  observed 
  in 
  the 
  substance 
  of 
  the 
  lacmitC, 
  

   although, 
  as 
  a 
  rule, 
  they 
  as 
  well 
  as 
  the 
  calcareous 
  bodies 
  were 
  absent. 
  

  

  