﻿Eartlnoorms 
  from 
  Henderson 
  Island. 
  257 
  

  

  guf 
  ; 
  its 
  dorsal 
  edge 
  is 
  very 
  convex 
  and 
  divided 
  into 
  3 
  to 
  5 
  

   lobes. 
  From 
  the 
  liilum 
  of 
  each 
  gland 
  originates 
  a 
  cylindrical 
  

   muscular 
  duct, 
  which 
  describes 
  an 
  S 
  and 
  opens 
  directly 
  to 
  

   the 
  exterior 
  ; 
  the 
  terminal 
  bursa 
  copulatrix 
  is 
  wanting, 
  

  

  Spermathecfe, 
  two 
  pairs^ 
  in 
  viii. 
  and 
  ix. 
  segments. 
  Each 
  

   spermatheca 
  has 
  a 
  medial 
  long 
  and 
  slightly 
  bent 
  muscular 
  

   duct. 
  The 
  main 
  pouch 
  has 
  the 
  same 
  length, 
  and 
  is 
  clearly 
  

   distinct 
  from 
  the 
  duct. 
  The 
  diverticulum 
  ends 
  in 
  a 
  spherical 
  

   or 
  oval 
  distal 
  extremity 
  ; 
  it 
  is 
  longer 
  than 
  the 
  main 
  pouch. 
  

   The 
  duct 
  of 
  the 
  diverticulum 
  is 
  S-shaped 
  at 
  its 
  base 
  and 
  

   diminishes 
  in 
  breadth 
  at 
  the 
  same 
  region 
  (text-fig.). 
  Before 
  and 
  

  

  Pherethna 
  hendersoniana, 
  sp. 
  n. 
  Spermatheca, 
  x 
  6. 
  

  

  behind 
  each 
  sperniathecal 
  pore, 
  at 
  the 
  internal 
  surface 
  of 
  the 
  

   body-wall, 
  a 
  whitish 
  glandular 
  mass 
  {gL) 
  is 
  recognizable. 
  

   Log. 
  Henderson 
  Island, 
  S. 
  Pacific 
  (D. 
  Tait 
  coll.). 
  

  

  Pherettma 
  montana, 
  Kinb., 
  subsp. 
  arthuri 
  (Benham). 
  

  

  Two 
  specimens. 
  

  

  Loc, 
  Henderson 
  Island, 
  S. 
  Pacific 
  (D. 
  Tait 
  coll.). 
  

  

  The 
  two 
  specimens 
  agree 
  particularly 
  with 
  Benliam^s 
  

   description 
  and 
  figures 
  of 
  Peridueta 
  arthuri, 
  Beidi.*. 
  This 
  

   species 
  is 
  arranged 
  by 
  Beddard 
  t 
  i'l 
  the 
  synonymic 
  list 
  of 
  

   Ph. 
  montana, 
  Kinb., 
  with 
  a 
  number 
  of 
  other 
  species 
  ; 
  but 
  

   more 
  recently 
  Ude 
  \ 
  separates 
  them 
  again 
  as 
  a 
  distinct 
  species. 
  

   I 
  prefer 
  a 
  middle 
  course, 
  and 
  give 
  to 
  Benham's 
  P. 
  arthuri 
  

   the 
  rank 
  of 
  subspecies 
  only. 
  

  

  In 
  a 
  specimen 
  from 
  the 
  above 
  locality 
  the 
  following 
  cha- 
  

   racters 
  are 
  noticeable 
  : 
  the 
  spermatheca? 
  open 
  to 
  the 
  exterior 
  

   in 
  intersegmental 
  furrow 
  vii/viii., 
  but 
  lie 
  in 
  the 
  vii. 
  segment; 
  

   instead 
  of 
  a 
  single 
  median 
  female 
  pore, 
  there 
  are 
  two 
  female 
  

   pores 
  close 
  to 
  the 
  middle 
  line 
  on 
  the 
  ventral 
  side 
  of 
  the 
  

   xiv. 
  segment. 
  

  

  * 
  Joiirn. 
  Liun. 
  Soc, 
  Zool. 
  xxvi. 
  1897, 
  p. 
  212, 
  pi. 
  xvi. 
  fig. 
  4«, 
  h, 
  

   t 
  Proc. 
  Zool. 
  Soc. 
  London, 
  1900, 
  p, 
  020. 
  

   X 
  Zeitsclirift 
  f. 
  -wiss. 
  Zool. 
  Ixxxiii. 
  p. 
  448, 
  

  

  