﻿MARINE 
  POLYCHAETE 
  WORMS 
  — 
  PETTIBONE 
  225 
  

  

  G^nus 
  Enipo 
  Malmgren, 
  1865, 
  sensu 
  Levinsen, 
  1883 
  

   Enipo 
  gracilis 
  Verrill, 
  1874 
  

  

  Enipo 
  gracilis 
  VerriU, 
  1874a, 
  pp. 
  407, 
  411, 
  pi. 
  6, 
  fig. 
  4; 
  1874b, 
  pp. 
  347, 
  361, 
  378, 
  

  

  pi. 
  5, 
  fig. 
  3.— 
  Pettibone, 
  1953, 
  p. 
  22, 
  pi. 
  7. 
  

   Enipo 
  cirrata 
  Treadwell, 
  1925, 
  p. 
  1, 
  figs. 
  1-4. 
  — 
  Hartman, 
  1938a, 
  p. 
  120, 
  &g. 
  39, 
  

  

  d, 
  e.— 
  Berkeley 
  and 
  Berkeley, 
  1942, 
  p. 
  188; 
  1945, 
  p. 
  322; 
  1948, 
  p. 
  16, 
  fig. 
  20. 
  

   Polynoe 
  gracilis 
  Hartman, 
  1942a, 
  p. 
  26, 
  figs. 
  23-26, 
  

  

  Description. 
  — 
  Length 
  25-76 
  mm., 
  width 
  including 
  setae 
  3-4 
  mm. 
  

   Segments 
  variable 
  in 
  number 
  (45, 
  with 
  regenerating 
  posterior 
  end, 
  

   to 
  74). 
  Body 
  elongate, 
  slender, 
  with 
  sides 
  nearly 
  parallel. 
  Prosto- 
  

   mium 
  without 
  cephalic 
  peaks. 
  In 
  some 
  specimens 
  from 
  New 
  England 
  

   there 
  are 
  slight 
  prostomial 
  peaks 
  (prostomial 
  peaks 
  present 
  — 
  Hart- 
  

   man, 
  1942). 
  Antennae 
  and 
  dorsal 
  cirri 
  with 
  short, 
  clavate 
  papillae. 
  

   Dorsal 
  cirri 
  short, 
  barely 
  reaching 
  tips 
  of 
  setae 
  in 
  anterior 
  part, 
  longer 
  

   in 
  posterior 
  region 
  without 
  elytra. 
  Elytra 
  oval, 
  translucent, 
  small, 
  

   usually 
  leaving 
  middorsum 
  uncovered, 
  smooth, 
  without 
  papillae 
  or 
  

   tubercles. 
  Notosetae 
  form 
  a 
  short, 
  bushy 
  bundle, 
  rather 
  numerous 
  

   (more 
  than 
  30 
  in 
  specimens 
  from 
  Point 
  Barrow) 
  to 
  few 
  (2-20 
  or 
  

   rarely 
  — 
  Treadwell, 
  1925), 
  slender 
  to 
  moderately 
  stout, 
  tapering 
  

   gradually 
  to 
  short, 
  bare, 
  blunt 
  tips, 
  with 
  spinous 
  rows 
  distally. 
  

   Neurosetae 
  stouter 
  than 
  notosetae, 
  upper 
  ones 
  with 
  longer 
  spinous 
  

   regions 
  (17-23 
  or 
  so 
  rows), 
  middle 
  ones 
  with 
  shorter 
  spinous 
  regions 
  

   (10 
  or 
  so 
  rows), 
  with 
  long, 
  bare, 
  slightly 
  hooked 
  tips 
  (neurosetae 
  may 
  

   be 
  all 
  similar, 
  with 
  5-10 
  transverse 
  spinous 
  rows) 
  . 
  Color 
  : 
  In 
  alcohol 
  : 
  

   Without 
  color 
  or 
  brownish 
  middorsally; 
  elytra 
  pigmented 
  smoky 
  

   brown 
  on 
  the 
  medial 
  halves. 
  

  

  Remarks. 
  — 
  -Known 
  to 
  be 
  commensal 
  with 
  the 
  maldanid 
  Nicomache 
  

   lumhricalis 
  (Fabricius) 
  in 
  Alaska 
  (as 
  E. 
  cirrata 
  — 
  Berkeley 
  and 
  Berke- 
  

   ley, 
  1942) 
  and 
  off 
  Halifax, 
  Nova 
  Scotia, 
  and 
  Cape 
  Cod 
  (specimens 
  in 
  

   the 
  U. 
  S. 
  National 
  Museum, 
  identified 
  by 
  Verrill). 
  

  

  New 
  Records. 
  — 
  Arctic 
  Alaska: 
  Off 
  Point 
  Barrow, 
  up 
  to 
  12.1 
  miles 
  

   from 
  shore, 
  21-123.5 
  fms., 
  from 
  breaking 
  rock, 
  masses 
  of 
  worm 
  tubes, 
  

   with 
  stones, 
  large 
  perforated 
  rocks 
  (3 
  stations, 
  3 
  specimens). 
  East 
  

   Coast 
  North 
  America: 
  Off 
  Nova 
  Scotia, 
  Maine, 
  Massachusetts, 
  2- 
  

   198 
  fms., 
  U. 
  S. 
  Fish 
  Commission. 
  

  

  Distribution. 
  — 
  Alaskan 
  Arctic; 
  southwestern 
  Alaska 
  to 
  Washington; 
  

   Nova 
  Scotia 
  to 
  Massachusetts. 
  In 
  2-123.5 
  fathoms. 
  

  

  Genus 
  Arcteobia 
  Annenkova, 
  1934 
  

   Arcteobia 
  anticostiensis 
  (Mcintosh, 
  1874) 
  

  

  Eupolynoe 
  anticostiensis 
  Mcintosh, 
  1874, 
  p. 
  265, 
  pi. 
  10, 
  figs. 
  1-4. 
  — 
  Wir6n, 
  1883, 
  

  

  p. 
  390, 
  pi. 
  29, 
  fig. 
  2.— 
  Marenzeller, 
  1890, 
  pi. 
  1. 
  

   Harmothoe 
  anticostiensis 
  Augener, 
  1928, 
  p. 
  691, 
  pi. 
  11, 
  fig. 
  13. 
  

  

  