﻿ON 
  A 
  NEW 
  SPECIES 
  OF 
  THE 
  GENUS 
  HAPLOTAXIS. 
  319 
  

  

  greater 
  part 
  of 
  the 
  wall 
  consists 
  of 
  circular 
  muscles, 
  between 
  which, 
  towards 
  

   the 
  external 
  surface, 
  bundles 
  of 
  longitudinal 
  muscles 
  are 
  intercalated. 
  

  

  Figs. 
  3 
  — 
  7 
  represent 
  five 
  sections 
  of 
  one 
  of 
  the 
  post-ovarian 
  nephridia, 
  as 
  

  

  seen 
  in 
  transverse 
  sections 
  of 
  the 
  immature 
  individual. 
  These 
  five 
  are 
  selected 
  

  

  out 
  of 
  nineteen 
  sections 
  which 
  involve 
  a 
  single 
  nephridium. 
  (Camera, 
  X 
  120.) 
  

  

  Fig. 
  3 
  shows 
  the 
  nephridial 
  funnel 
  projecting 
  through 
  a 
  septum, 
  and 
  a 
  

  

  small 
  part 
  of 
  the 
  post-septal 
  region 
  of 
  the 
  nephridium. 
  

   Fig. 
  4 
  is 
  at 
  about 
  the 
  middle 
  of 
  the 
  series, 
  showing 
  the 
  nephridium 
  at 
  its 
  

  

  greatest 
  height. 
  

   Fig. 
  5 
  involves 
  the 
  muscles 
  of 
  the 
  ventral 
  chseta 
  ; 
  the 
  nephridium 
  is 
  

  

  passing 
  downwards 
  towards 
  the 
  body-wall. 
  

   Fig. 
  6 
  is 
  a 
  few 
  sections 
  onwards. 
  

  

  Fig. 
  7 
  shows 
  the 
  short 
  " 
  duct," 
  represented 
  by 
  more 
  granular 
  cells 
  (see 
  

   fig. 
  10). 
  

  

  Fig. 
  8. 
  — 
  An 
  enlarged 
  view 
  of 
  a 
  nephridium 
  in 
  such 
  a 
  section 
  as 
  is 
  repre- 
  

   sented 
  in 
  fig. 
  4. 
  (Camera, 
  X 
  500 
  ; 
  details 
  as 
  seen 
  with 
  Leitz, 
  J^ 
  homog. 
  

   imm. 
  lens.) 
  The 
  vacuolated 
  condition 
  of 
  the 
  large 
  nepliridial 
  cells, 
  and 
  the 
  

   distinct 
  " 
  wall 
  " 
  to 
  the 
  canal 
  are 
  seen. 
  

  

  Fig. 
  9. 
  — 
  A 
  funnel 
  of 
  a 
  post-ovarian 
  nephridium 
  from 
  a 
  longitudinal 
  section, 
  

   which 
  is 
  neither 
  sagittal 
  nor 
  frontal, 
  but 
  which 
  cuts 
  the 
  worm 
  obliquely. 
  

   (Camera, 
  X 
  700.) 
  No 
  details 
  of 
  cell-structure 
  are 
  shown. 
  

  

  Figs. 
  10, 
  11. 
  — 
  Two 
  consecutive 
  sections 
  through 
  the 
  "duct" 
  of 
  the 
  

   nephridium. 
  (Camera, 
  x 
  700; 
  details 
  under 
  J^ 
  ^'om. 
  imm.) 
  The 
  cytoplasm 
  

   of 
  the 
  nephridial 
  cells, 
  or 
  better 
  " 
  syncytium," 
  is 
  no 
  longer 
  vacuolated, 
  but 
  

   highly 
  granular. 
  

  

  Fig. 
  10 
  is 
  a 
  highly 
  magnified 
  view 
  of 
  fig. 
  7. 
  

  

  Fig. 
  11 
  is 
  the 
  next 
  section. 
  It 
  shows 
  the 
  " 
  duct 
  " 
  passing 
  into 
  and 
  

   through 
  the 
  epidermis, 
  from 
  which 
  it 
  is 
  readily 
  distinguished. 
  I 
  was 
  

   unable 
  to 
  trace 
  the 
  canal 
  to 
  a 
  pore. 
  

  

  Fig. 
  12. 
  — 
  A 
  transverse 
  section 
  through 
  the 
  body 
  of 
  the 
  mature 
  individual, 
  

   nvolving 
  the 
  first 
  nephridium 
  in 
  Segment 
  X. 
  (Camera, 
  X 
  120.) 
  

  

  Fig. 
  13. 
  — 
  The 
  same 
  nephridium 
  — 
  next 
  section 
  — 
  more 
  highly 
  magnified. 
  

   (Camera, 
  x 
  700.) 
  The 
  cytoplasmic 
  network 
  not 
  indicated. 
  Towards 
  the 
  

   upper 
  part 
  of 
  the 
  organ 
  the 
  wall 
  of 
  the 
  canal 
  («.) 
  is 
  much 
  thicker 
  than 
  else- 
  

   where. 
  

  

  Fig. 
  1 
  4. 
  — 
  The 
  funnel 
  of 
  the 
  first 
  nephridium, 
  as 
  seen 
  in 
  a 
  longitudinal 
  section 
  

   of 
  the 
  immature 
  individual. 
  It 
  is 
  smaller 
  than 
  that 
  of 
  the 
  post-ovarian 
  

   funnel 
  (cf. 
  fig. 
  9). 
  (Camera, 
  x 
  700.) 
  

  

  Fig. 
  15. 
  — 
  A 
  transverse 
  section 
  of 
  the 
  body 
  through 
  the 
  oesophageal 
  region 
  

   (X 
  120), 
  showing 
  the 
  relative 
  sizes 
  of 
  the 
  dorsal 
  and 
  ventral 
  chaetse. 
  

  

  