﻿ECHIUKOID 
  WORMS 
  OF 
  NORTH 
  PACIFIC 
  FISHER 
  255 
  

  

  EUBONELLIA, 
  new 
  genus 
  

  

  Diagnosis. 
  — 
  Bonclliidae 
  with 
  woll-dovolopcd 
  l)ifurcate 
  prol)oscis, 
  

   110 
  setae, 
  and 
  a 
  single 
  (right) 
  nephricUuni, 
  the 
  iHstal 
  end 
  of 
  which 
  is 
  

   expanch^d 
  mto 
  the 
  plicated 
  rim 
  of 
  the 
  large 
  nephrostome; 
  anal 
  vesicles 
  

   essentially 
  as 
  in 
  Bonellia; 
  male 
  with 
  sperm 
  receptacle 
  reaching 
  nearly 
  

   to 
  posterior 
  end 
  of 
  body; 
  body 
  wall 
  thick. 
  

  

  Type, 
  Eubonellia 
  valida, 
  new 
  species. 
  

  

  Rrmarhs. 
  — 
  Tliis 
  genus 
  differs 
  from 
  Bonelliopsis, 
  the 
  only 
  other 
  

   known 
  to 
  have 
  a 
  strictly 
  terminal 
  nephrostome, 
  in 
  lackuig 
  setae. 
  

   Its 
  foregut 
  has 
  an 
  unusually 
  extensive 
  stomach 
  or 
  crop, 
  between 
  the 
  

   gizzard 
  and 
  begnunng 
  of 
  siphon, 
  this 
  segment 
  being 
  short 
  in 
  Bonelli- 
  

   opsis. 
  The 
  mesenteries 
  of 
  the 
  mtestine 
  of 
  Eubonellia 
  are 
  m 
  the 
  form 
  

   of 
  strands, 
  not 
  a 
  sheet. 
  

  

  Parabonellia 
  Onoda, 
  '* 
  based 
  on 
  Bonellia 
  misakiensis 
  Ikeda,'^ 
  also 
  

   lacks 
  setae 
  in 
  both 
  male 
  and 
  female. 
  The 
  nephridium 
  has 
  a 
  small 
  

   pedunculate 
  funnel 
  situated, 
  not 
  at 
  the 
  base 
  as 
  in 
  Bonellia, 
  but 
  on 
  the 
  

   side 
  of 
  the 
  vesicle 
  near 
  the 
  terminal 
  blind 
  end. 
  Ikcda 
  did 
  not 
  show 
  

   this 
  in 
  his 
  figure 
  of 
  a 
  "dissection" 
  of 
  the 
  type, 
  but 
  it 
  is 
  figured 
  by 
  

   Onoda 
  (fig. 
  1) 
  and 
  Sato 
  '^ 
  (fig. 
  2). 
  None 
  of 
  these 
  writers 
  has 
  figured 
  or 
  

   described 
  significant 
  details 
  of 
  the 
  foregut, 
  which 
  are 
  of 
  importance 
  in 
  

   classification. 
  

  

  The 
  body 
  wall 
  of 
  Parabonellia 
  is 
  thin 
  whUe 
  that 
  of 
  Eubonellia 
  is 
  

   very 
  muscular, 
  but 
  this 
  is 
  a 
  character 
  varying 
  with 
  the 
  contraction 
  of 
  

   the 
  specimen 
  and 
  is 
  scarcely 
  of 
  generic 
  significance. 
  

  

  In 
  Eubonellia 
  the 
  male 
  is 
  about 
  half 
  the 
  size 
  of 
  the 
  male 
  of 
  Para- 
  

   bonellia, 
  which 
  is 
  described 
  as 
  nematodelike, 
  3.3 
  to 
  3.5 
  mm. 
  long, 
  and 
  

   0.2 
  to 
  0.3 
  mm. 
  in 
  breadth. 
  The 
  sperm 
  vesicle 
  and 
  canal 
  occupy 
  the 
  

   anterior 
  fifth 
  to 
  third 
  of 
  the 
  body. 
  In 
  Eubonellia 
  the 
  vesicle 
  extends 
  

   nearly 
  to 
  the 
  posterior 
  end 
  of 
  the 
  bodv, 
  which 
  is 
  depressed, 
  planarian- 
  

   like. 
  

  

  Profoboncllia 
  Ikcda 
  '* 
  (type, 
  P. 
  mitsukurii, 
  Sagami 
  Bay, 
  Japan, 
  300 
  

   fathoms) 
  has 
  very 
  strong 
  setae 
  with 
  unusually 
  well 
  developed 
  muscles. 
  

   The 
  proboscis 
  is 
  similar 
  to 
  that 
  of 
  ThahisKema, 
  and 
  the 
  single 
  (left) 
  

   nephridium 
  is 
  similar 
  to 
  that 
  of 
  Bonellia. 
  The 
  nephrostome 
  is 
  a 
  wide 
  

   fimbriated 
  funnel 
  at 
  the 
  end 
  of 
  a 
  slender 
  tube 
  opening 
  into 
  the 
  nephrid- 
  

   ium 
  near 
  the 
  base 
  of 
  that 
  organ. 
  The 
  anal 
  vesicles 
  aic 
  similar 
  to 
  

   those 
  of 
  Bonellia 
  rather 
  than 
  Ilamingia, 
  which 
  the 
  proboscis 
  might 
  

   lead 
  one 
  to 
  expect. 
  The 
  vascular 
  system 
  seems 
  to 
  possess 
  a 
  peculiarity 
  

   in 
  a 
  rather 
  direct 
  connection 
  between 
  the 
  dorsal 
  vessel 
  and 
  the 
  neuro- 
  

   intestinal 
  connective 
  at 
  a 
  point 
  immediately 
  anterior 
  (o 
  the 
  be- 
  

   giiming 
  of 
  the 
  siphon. 
  Ikeda 
  treats 
  this 
  very 
  summarily 
  in 
  both 
  

  

  "• 
  On<xln 
  1«H, 
  p. 
  418 
  (PtnidofiontlUa); 
  1035. 
  p. 
  HI 
  (.Parabonfllia 
  for 
  PteudobontUia, 
  prcocciiple<l). 
  

   '• 
  Ik<yU, 
  1W>I, 
  p. 
  74, 
  flKS. 
  24, 
  103-105. 
  

   " 
  ."^alo, 
  1935, 
  p. 
  142, 
  Ors. 
  1,2. 
  

   '• 
  Ikcda. 
  1808*. 
  p. 
  259. 
  figs. 
  1-4. 
  

  

  