﻿MARINE 
  POLYCHAETE 
  WORMS 
  — 
  PETTIBONE 
  275 
  

  

  except 
  they 
  may 
  be 
  longer 
  and 
  more 
  numerous. 
  Proboscis 
  without 
  

   chevrons; 
  proboscidial 
  organs 
  (horny, 
  yellow, 
  spinous 
  processes) 
  of 
  

   several 
  kinds 
  arranged 
  in 
  longitudinal 
  series. 
  Color: 
  In 
  alcohol: 
  

   Uniformly 
  greenish 
  brown 
  or 
  somewhat 
  banded 
  with 
  one 
  wide, 
  dark- 
  

   greenish-brown 
  band 
  per 
  segment; 
  iridescent. 
  

  

  New 
  records. 
  — 
  Arctic 
  Alaska: 
  Off 
  Point 
  Barrow 
  base, 
  up 
  to 
  4 
  

   miles 
  from 
  shore, 
  23 
  to 
  29.1 
  fms., 
  on 
  various 
  combinations 
  of 
  mud, 
  

   sand, 
  gravel, 
  stones, 
  rocks, 
  shells 
  (3 
  stations, 
  5 
  specimens). 
  

  

  Distribviion. 
  — 
  Arctic 
  Alaska 
  to 
  Bering 
  Sea. 
  In 
  23 
  to 
  29 
  fathoms. 
  

  

  Family 
  Lumbrineridae 
  

  

  Body 
  elongate, 
  cylindrical, 
  tapered 
  slightly 
  anteriorly 
  and 
  more 
  

   strongly 
  posteriorly, 
  superficially 
  resembling 
  oligochaetes. 
  Pro- 
  

   stomium 
  conical 
  to 
  rounded, 
  with 
  a 
  pair 
  of 
  nuchal 
  organs 
  on 
  posterior 
  

   margin, 
  without 
  antennae 
  or 
  palps 
  (fig. 
  31, 
  h). 
  First 
  two 
  segments 
  

   apodous 
  and 
  achaetous, 
  without 
  tentacular 
  cirri. 
  Without 
  dorsal 
  

   and 
  ventral 
  cirri. 
  Two 
  to 
  four 
  anal 
  cirri. 
  Parapodia 
  imiramous. 
  

   Proboscis 
  eversible, 
  with 
  dark, 
  chitinous, 
  well-developed 
  masticatory 
  

   apparatus 
  consisting 
  of 
  a 
  pair 
  of 
  ventral 
  mandibles 
  and 
  four 
  pairs 
  of 
  

   maxillary 
  plates 
  (fig. 
  31, 
  i,j). 
  

  

  Represented 
  by 
  a 
  single 
  species 
  from 
  Point 
  Barrow. 
  

  

  G^nus 
  Lumbrineris 
  Blainville, 
  1828 
  

   Lumbrineris 
  fragilis 
  (O. 
  F. 
  Miiller, 
  1776) 
  

  

  Figure 
  31, 
  h-n 
  

  

  Lumbricus 
  fragilis 
  Miiller, 
  1776, 
  p. 
  216; 
  1788, 
  p. 
  22, 
  pi. 
  22, 
  figs. 
  1-3. 
  

  

  Lumbrinereis 
  fragilis 
  Malmgren, 
  1867, 
  pi. 
  14, 
  fig. 
  83. 
  — 
  Chamberlin, 
  1920, 
  p. 
  15. 
  — 
  

   Eliason, 
  1920, 
  p. 
  33.— 
  Berkeley 
  and 
  Berkeley, 
  1943, 
  p. 
  130. 
  

  

  Lumbriconereis 
  minuta 
  Th^el, 
  1879, 
  p. 
  42, 
  pi. 
  4, 
  figs. 
  57-59. 
  — 
  Fauvel, 
  1911, 
  p. 
  

   22.— 
  Augener, 
  1928, 
  p. 
  732.— 
  Wesenberg-Lund, 
  1950a, 
  p. 
  28; 
  1950b, 
  p. 
  71. 
  

  

  Lumbriconereis 
  fragilis 
  Fauvel, 
  1923, 
  p. 
  430, 
  fig. 
  171, 
  k, 
  I. 
  — 
  Augener, 
  1928, 
  p. 
  

   730, 
  pi. 
  11, 
  fig. 
  5.— 
  Annenkova, 
  1937, 
  p. 
  167; 
  1938, 
  p. 
  167.— 
  Gorbunov, 
  1946, 
  

   p. 
  39.— 
  Thorson, 
  1946, 
  p. 
  74.— 
  Zatsepin, 
  1948, 
  p. 
  124, 
  pi. 
  31, 
  fig. 
  14,— 
  

   Wesenberg-Lund, 
  1950a, 
  p. 
  27; 
  1950b, 
  p. 
  69; 
  1951, 
  p. 
  55. 
  

  

  Lumbrineris 
  fragilis 
  Hartman, 
  1944a, 
  pp. 
  335, 
  340. 
  

  

  Description. 
  — 
  Length 
  150-250 
  mm., 
  width 
  without 
  setae 
  up 
  to 
  7 
  

   mm., 
  width 
  with 
  setae 
  12 
  mm. 
  Prostomium 
  conical, 
  pointed. 
  First 
  

   two 
  achaetous 
  segments 
  about 
  equal 
  to 
  the 
  following 
  segments 
  or 
  the 
  

   first 
  one 
  slightly 
  longer. 
  Parapodia 
  without 
  branchiae, 
  with 
  presetal 
  

   lobe 
  short, 
  rounded 
  ; 
  postsetal 
  lobe 
  in 
  anterior 
  region 
  of 
  body 
  slightly 
  

   longer, 
  rounded, 
  diagonally 
  truncate; 
  in 
  middle 
  and 
  posterior 
  regions 
  

   of 
  body, 
  postsetal 
  lobe 
  extended 
  somewhat 
  dorsally, 
  somewhat 
  digiti- 
  

   form; 
  with 
  arched 
  limbate 
  setae 
  with 
  fine 
  capillary 
  tips, 
  dark 
  amber- 
  

   colored 
  on 
  basal 
  half, 
  on 
  first 
  60-100 
  setigers; 
  with 
  simple 
  (not 
  com- 
  

   pound), 
  hooded, 
  hooked 
  setae, 
  dark 
  amber-colored 
  basally, 
  beginning 
  

  

  