﻿ON 
  A 
  NEW 
  SPE(!IBS 
  OF 
  THE 
  GENUS 
  HAPLOTAXIS. 
  301 
  

  

  gyne. 
  The 
  two 
  pairs 
  of 
  spermathecae 
  open 
  at 
  the 
  anterior 
  

   margins 
  of 
  Segments 
  VIII 
  and 
  IX. 
  

  

  Internal 
  Anatomy. 
  

  

  Alimentary 
  System. 
  — 
  The 
  buccal 
  region 
  is 
  noticeably 
  

   long, 
  extending 
  through 
  the 
  three 
  auterior 
  segments 
  of 
  the 
  

   body; 
  there 
  is 
  no 
  pharynx, 
  but 
  the 
  buccal 
  tube 
  opens 
  into 
  a 
  

   gizzard 
  in 
  Segment 
  IV 
  (fig. 
  1, 
  g). 
  This 
  organ 
  is 
  very 
  different 
  

   structurally 
  from 
  a 
  pharynx, 
  for 
  which 
  it 
  may 
  easily 
  be 
  

   mistaken 
  unless 
  the 
  worm 
  be 
  studied 
  by 
  means 
  of 
  sections. 
  

  

  It 
  is 
  a 
  cylindrical 
  organ, 
  lined 
  by 
  a 
  thick 
  cuticle 
  (fig. 
  2) 
  ; 
  

   the 
  wall 
  is 
  for 
  the 
  greater 
  part 
  of 
  its 
  extent 
  muscular; 
  the 
  

   muscle 
  is 
  equally 
  developed 
  on 
  all 
  sides, 
  and 
  consists 
  in 
  the 
  

   main 
  of 
  a 
  thick 
  circular 
  coat, 
  outside 
  which 
  is 
  a 
  layer 
  of 
  

   longitudinal 
  fibres, 
  together 
  Avith 
  others 
  intermingled 
  with 
  

   the 
  outer 
  lamellse 
  of 
  the 
  circular 
  coat. 
  A 
  distinct 
  coelomic 
  

   epithelinin 
  surrounds 
  the 
  whole. 
  From 
  its 
  dorsal 
  and 
  lateral 
  

   walls 
  a 
  few 
  muscle-slips 
  pass 
  to 
  the 
  body-wall. 
  

  

  In 
  the 
  posterior 
  third 
  of 
  the 
  organ 
  the 
  muscular 
  coat 
  

   diminishes 
  gradually, 
  and 
  the 
  epithelial 
  cells 
  exhibit 
  more 
  or 
  

   less 
  numerous 
  goblet-cells, 
  the 
  contained 
  secretion 
  of 
  which 
  is 
  

   not 
  stained 
  by 
  hfemalum 
  ; 
  these 
  goblet-cells 
  open 
  by 
  distinct 
  

   holes 
  through 
  the 
  cuticle. 
  

  

  Such 
  a 
  structure 
  more 
  nearly 
  resembles 
  a 
  gizzard 
  than 
  a 
  

   '^pharynx;" 
  there 
  is 
  no 
  "dorsal 
  muscular 
  pad," 
  such 
  as 
  

   occurs 
  in 
  Euchytrseids, 
  nor 
  is 
  there 
  any 
  " 
  dorsal 
  ciliated 
  

   pouch," 
  such 
  as 
  is 
  met 
  with 
  in 
  many 
  earthworms 
  as 
  well 
  as 
  

   most 
  aquatic 
  Oligochaetes. 
  The 
  presence 
  of 
  a 
  gizzard 
  in 
  a 
  so- 
  

   called 
  'Mimicoline" 
  member 
  of 
  the 
  order 
  breaks 
  down 
  one 
  

   more 
  of 
  the 
  barriers 
  which 
  were 
  fonnerly 
  supposed 
  to 
  separate 
  

   the 
  aquatic 
  from 
  the 
  terrestrial 
  Oligochsetes 
  ; 
  and 
  it 
  is 
  

   remarkable 
  that 
  both 
  Haplotaxis 
  gordioides 
  and 
  H. 
  

   heterogyne, 
  purely 
  aquatic 
  worms, 
  should 
  possess 
  a 
  gizzard, 
  

   whilst 
  the 
  majority 
  of 
  aquatic 
  species 
  of 
  terrestrial 
  genera 
  

   lose 
  the 
  gizzard.^ 
  

  

  ' 
  In 
  looking 
  up 
  tlie 
  literature 
  of 
  the 
  sul)ject, 
  after 
  writing 
  out 
  my 
  notes, 
  I 
  

   VOL. 
  48, 
  PAKT 
  2. 
  NKW 
  SEIUKS. 
  21 
  

  

  