﻿NO. 
  1959. 
  SIPUNCVLIDS 
  OF 
  EASTERN 
  NORTH 
  AMERICA— 
  GEROULD. 
  431 
  

  

  longitudinal 
  bands. 
  In 
  this 
  respect 
  his 
  specimens 
  agree 
  more 
  closely 
  

   with 
  S. 
  phalloides 
  Pallas 
  of 
  the 
  West 
  Indies. 
  

  

  The 
  glans, 
  as 
  the 
  smooth 
  posterior 
  end 
  of 
  the 
  body 
  is 
  called, 
  is 
  not 
  

   marked 
  off 
  from 
  the 
  rest 
  of 
  the 
  trunk 
  by 
  an 
  annular 
  prepuce-Uke 
  

   fold; 
  and 
  Theel 
  also 
  found, 
  as 
  his 
  excellent 
  figure 
  137 
  shows, 
  that 
  no 
  

   fold 
  of 
  this 
  sort 
  occurs 
  in 
  several 
  of 
  the 
  specimens 
  from 
  off 
  the 
  coast 
  

   of 
  Norway 
  that 
  he 
  examined, 
  hence 
  it 
  is 
  evidentlj^ 
  not 
  a 
  characteristic 
  

   of 
  any 
  morphological 
  importance. 
  

  

  The 
  dorsal 
  retractor 
  muscles 
  in 
  the 
  American 
  variety 
  spring 
  from 
  

   a 
  single 
  muscle 
  band, 
  the 
  ventral 
  from 
  two, 
  and 
  not 
  in 
  each 
  case 
  from 
  

   three 
  or 
  four 
  as 
  in 
  the 
  Scandinavian 
  form. 
  

  

  Trunk 
  cylindrical. 
  As 
  shown 
  in 
  Theel's 
  excellent 
  figure 
  it 
  is 
  110 
  

   mm. 
  long 
  and 
  16 
  thick; 
  in 
  the 
  contracted 
  specimens 
  from 
  station 
  

   2709, 
  south 
  of 
  Georges 
  Bank, 
  it 
  is 
  75 
  mm. 
  long 
  and 
  20 
  nmi. 
  thick. 
  

   The 
  introvert 
  is 
  distinctly 
  marked 
  off 
  from 
  the 
  trunk, 
  and 
  is 
  of 
  much 
  

   smaller 
  diameter. 
  It 
  is 
  about 
  one-fourth 
  as 
  long 
  as 
  the 
  trunk. 
  The 
  

   crown 
  of 
  tentacles 
  consists 
  of 
  8-12 
  primary 
  lobes. 
  The 
  surface 
  of 
  

   the 
  trunk, 
  except 
  at 
  the 
  posterior 
  extremity, 
  is 
  corrugated 
  with 
  

   21-24 
  longitudinal 
  ridges 
  and 
  an 
  equal 
  number 
  of 
  furrows. 
  Under- 
  

   lying 
  each 
  furrow 
  and 
  giving 
  rise 
  to 
  it 
  is 
  a 
  longitudinal 
  muscle 
  band. 
  

   Each 
  ridge 
  contains 
  a 
  longitudinal 
  canal, 
  which 
  communicates 
  with 
  

   the 
  ccelom 
  by 
  numerous 
  transverse 
  slits 
  in 
  the 
  layer 
  of 
  circular 
  

   muscles 
  in 
  the 
  interstices 
  among 
  the 
  longitudinal 
  muscle 
  bands. 
  The 
  

   posterior 
  extremity 
  of 
  the 
  trunk 
  is 
  smooth, 
  the 
  longitudinal 
  muscle 
  

   fibers 
  there 
  forming 
  a 
  thin 
  continuous 
  layer 
  rather 
  than 
  separate 
  

   muscle 
  bands. 
  

  

  No 
  papillae 
  that 
  are 
  visible 
  to 
  the 
  nailed 
  eye 
  are 
  found 
  on 
  the 
  trank, 
  

   though 
  very 
  minute, 
  dome-shaped 
  elevations 
  may 
  be 
  detected 
  with 
  

   a 
  low 
  power 
  of 
  the 
  compound 
  microscope, 
  especially 
  at 
  the 
  posterior 
  

   extremity. 
  The 
  introvert, 
  except 
  immediately 
  behind 
  the 
  tentacles, 
  

   is 
  covered 
  Avith 
  prominent 
  papillas 
  in 
  the 
  shape 
  of 
  rounded 
  cones, 
  

   usually 
  slightly 
  longer 
  than 
  thick, 
  and 
  recurved. 
  

  

  The 
  anus 
  is 
  prominent, 
  and 
  lies 
  between 
  one-fifth 
  and 
  one-fourth 
  

   of 
  the 
  length 
  of 
  the 
  trunk 
  behind 
  the 
  anterior 
  end. 
  The 
  openings 
  of 
  

   the 
  ncphridia 
  lie 
  in 
  front 
  of 
  the 
  anus, 
  about 
  one-half 
  of 
  the 
  distance 
  

   between 
  the 
  latter 
  and 
  the 
  anterior 
  end 
  of 
  the 
  trunk. 
  

  

  The 
  four 
  retractor 
  muscles. 
  all 
  arise 
  from 
  the 
  body 
  wall 
  at 
  about 
  

   one-fourth 
  of 
  the 
  distance 
  behind 
  the 
  anterior 
  extremity 
  of 
  the 
  trunk, 
  

   and 
  slightly 
  behind 
  the 
  anus. 
  The 
  origin 
  of 
  the 
  ventral 
  pair 
  is 
  slightly 
  

   behind 
  that 
  of 
  the 
  dorsal. 
  Each 
  ventral 
  retractor 
  in 
  the 
  variety 
  

   americana 
  is 
  attached 
  to 
  two 
  longitudinal 
  muscle 
  bands; 
  each 
  dorsal 
  

   to 
  a 
  single 
  longitudinal 
  muscle 
  band. 
  

  

  The 
  intestinal 
  coil 
  is 
  held 
  to 
  the 
  body 
  wall 
  by 
  numerous 
  muscle 
  

   strands, 
  and 
  the 
  rectum 
  is 
  held 
  by 
  a 
  pair 
  of 
  strong 
  muscles, 
  the 
  

   attachments 
  of 
  which 
  are 
  close 
  beside 
  those 
  of 
  the 
  dorsal 
  retractors. 
  

  

  