﻿MARINE 
  POLYCHAETE 
  WORMS 
  — 
  PETTIBONE 
  247 
  

  

  eggs, 
  was 
  dredged 
  in 
  27 
  fathoms 
  February 
  18, 
  1950. 
  (A 
  2-lobed 
  

   egg 
  mass 
  is 
  carried 
  ventrally 
  — 
  Wesenberg-Lund, 
  1947.) 
  

  

  Male 
  stolon 
  (Polyhostrichus) 
  : 
  No 
  specimens 
  taken 
  from 
  Point 
  

   Barrow. 
  A 
  specimen 
  taken 
  in 
  plankton 
  at 
  Portage 
  Bay, 
  Alaska, 
  was 
  

   12 
  mm. 
  long, 
  1.5 
  mm. 
  wide 
  without 
  setae, 
  4 
  mm. 
  wide 
  including 
  

   swimming 
  setae, 
  with 
  61 
  setigers 
  consisting 
  of 
  14 
  anterior, 
  36 
  median, 
  

   and 
  11 
  posterior 
  segments. 
  Prostomium 
  similar 
  to 
  A. 
  fallax; 
  two 
  

   pairs 
  tentacular 
  cirri, 
  upper 
  pair 
  longer. 
  First 
  pair 
  dorsal 
  cirri 
  on 
  

   first 
  setiger 
  very 
  long, 
  similar 
  to 
  median 
  antenna 
  (achaetous 
  — 
  ^Wesen- 
  

   berg-Lund, 
  1947); 
  dorsal 
  cirri 
  in 
  anterior 
  region 
  long, 
  unequal; 
  in 
  

   middle 
  region 
  short, 
  about 
  one-third 
  length 
  of 
  elongated 
  parapodial 
  

   lobes. 
  Large 
  epaulettes 
  on 
  first 
  three 
  setigers. 
  

  

  New 
  records. 
  — 
  Arctic 
  Alaska: 
  Off 
  Point 
  Barrow 
  base, 
  16.7-123.5 
  

   fms., 
  up 
  to 
  15 
  mUes 
  from 
  shore, 
  on 
  bottoms 
  of 
  stones, 
  worm 
  tubes, 
  and 
  

   various 
  combinations 
  of 
  mud, 
  pebbles, 
  gravel, 
  stones, 
  rocks, 
  large 
  

   perforated 
  rocks, 
  with 
  bryozoans, 
  hydroids, 
  shells, 
  and 
  worm 
  tubes 
  

   (17 
  stations, 
  53 
  specimens). 
  West 
  Coast 
  North 
  America: 
  Albatross 
  

   surface 
  station, 
  Portage 
  Bay, 
  Alaska; 
  San 
  Juan 
  Channel, 
  Washington 
  

   Sound, 
  25 
  fms., 
  Pettibone, 
  1940. 
  East 
  Coast 
  North 
  America: 
  Off 
  

   Labrador, 
  30-40 
  fms.. 
  Blue 
  Dolphin 
  Expedition, 
  1949; 
  Woods 
  Hole 
  

   region, 
  Massachusetts, 
  Pettibone, 
  1950. 
  

  

  Distribution. 
  — 
  Scattered 
  records 
  in 
  the 
  Arctic: 
  Arctic 
  Alaska, 
  

   Greenland, 
  Spitsbergen, 
  Franz 
  Josef 
  Land, 
  Barents 
  Sea. 
  Also 
  Iceland; 
  

   Labrador 
  to 
  North 
  Carolina; 
  Bering 
  Sea 
  to 
  Washington. 
  In 
  low 
  

   water 
  to 
  123.5 
  fathoms; 
  sexual 
  forms 
  at 
  surface. 
  

  

  Autolytus 
  fallax 
  Malmgren, 
  1867 
  

  

  Figure 
  29, 
  c-f 
  

  

  ? 
  Polyhostrichus 
  longosetosus 
  Oersted, 
  1843, 
  p. 
  183, 
  pi. 
  5, 
  figs. 
  62, 
  67, 
  71. 
  — 
  Tread- 
  

  

  weU, 
  1937, 
  p. 
  28. 
  

   Autolytus 
  fallax 
  Malmgren, 
  1867, 
  p. 
  33, 
  pi. 
  6, 
  fig. 
  41.— 
  Ditlevsen, 
  1929, 
  p. 
  17. 
  

   ? 
  Autolytus 
  longisetosus 
  Malmgren, 
  1867, 
  p. 
  34, 
  pi. 
  7, 
  fig. 
  38. 
  

   Autolytus 
  prolifer 
  Augener, 
  1913, 
  p. 
  258; 
  1928, 
  p. 
  724. 
  — 
  Wesenberg-Lund, 
  1947, 
  

  

  p. 
  19, 
  figs. 
  8, 
  9 
  (part; 
  not 
  Nereis 
  prolifera 
  Miiller, 
  1788). 
  

   Autolytus 
  prismaticus 
  Wesenberg-Lund, 
  1947, 
  p. 
  24 
  (part; 
  not 
  Nereis 
  prismatica 
  

  

  Fabricius, 
  1780). 
  

  

  Description. 
  — 
  Stem 
  form: 
  Length 
  3-18 
  mm., 
  width 
  without 
  setae 
  

   0.3-0.7 
  mm,, 
  up 
  to 
  45-78 
  segments. 
  Median 
  antenna 
  and 
  first 
  pair 
  

   dorsal 
  cirri 
  very 
  long; 
  lateral 
  antennae 
  and 
  upper 
  tentacular 
  cirri 
  

   about 
  half 
  as 
  loDg; 
  lower 
  pair 
  tentacular 
  cirri 
  and 
  second 
  pair 
  dorsal 
  

   cirri 
  shorter, 
  about 
  twice 
  the 
  length 
  of 
  the 
  following 
  cirri 
  ; 
  rest 
  of 
  dorsal 
  

   cirri 
  short, 
  less 
  than 
  half 
  the 
  body 
  width 
  and 
  extending 
  only 
  slightly 
  

   beyond 
  the 
  setae, 
  subequal. 
  Short 
  epaulettes 
  (a 
  pair 
  of 
  shallow, 
  semi- 
  

   circular 
  raised 
  areas) 
  on 
  tentacular 
  segment 
  only. 
  Of 
  68 
  specimens 
  of 
  

   the 
  stem 
  form, 
  45 
  showed 
  bud 
  formation 
  of 
  the 
  sexual 
  stolons, 
  the 
  

  

  