﻿NO. 
  195D. 
  SIPU^CULIDS 
  OF 
  EASTERN 
  NORTH 
  AMERICA— 
  GEROVLD. 
  381 
  

  

  PHASCOLOSOMA 
  MARGARITACEUM 
  (Sars). 
  

  

  Sipunculus 
  margaritaceus 
  Sars, 
  1851. 
  

  

  Phascolosoma 
  oerstedii 
  Kkferstein, 
  1865.— 
  Theel, 
  1875. 
  

  

  Phascolosoma 
  fidgens 
  Theel, 
  1875 
  (young?). 
  

  

  Phascolosoma 
  alhidum 
  Theel, 
  1875 
  (young). 
  

  

  Phascolosoma 
  margaritaceum 
  Koeen 
  and 
  Danielssen, 
  1877. 
  

  

  Specimens 
  were 
  taken 
  from 
  the 
  following 
  localities 
  off 
  the 
  coast 
  of 
  

   North 
  America 
  : 
  

  

  Station 
  2463, 
  Green 
  Bank, 
  south 
  of 
  Newfoundland, 
  lat. 
  45° 
  44' 
  N.; 
  

   long. 
  54° 
  27' 
  W.; 
  45 
  fathoms, 
  broken 
  shells; 
  temperature 
  at 
  bottom, 
  

   30° 
  F. 
  

  

  Station 
  2466, 
  Green 
  Bank, 
  south 
  of 
  Newfoundland, 
  lat. 
  45° 
  29' 
  N.; 
  

   long. 
  55° 
  24' 
  W.; 
  67 
  fathoms, 
  coral; 
  temperature 
  at 
  bottom, 
  30° 
  F. 
  

  

  Gulf 
  of 
  St. 
  Lawrence, 
  J. 
  T. 
  Wliiteaves, 
  1872 
  ; 
  30 
  fathoms. 
  (Hitherto 
  

   erroneously 
  referred 
  to 
  by 
  Verrill, 
  1874, 
  and 
  others 
  as 
  Ph. 
  horeale.) 
  

  

  Station 
  2491, 
  Misaine 
  Bank, 
  east 
  of 
  Cape 
  Breton, 
  lat. 
  45° 
  24' 
  30" 
  

   N.; 
  long. 
  58° 
  35' 
  15" 
  W.; 
  59 
  fathoms, 
  white 
  sand. 
  

  

  Station 
  2492, 
  Misaine 
  Bank, 
  east 
  of 
  Cape 
  Breton, 
  lat. 
  45° 
  22' 
  N.; 
  

   long. 
  58° 
  43' 
  45" 
  W.; 
  75 
  fathoms, 
  white 
  sand; 
  temperature 
  at 
  bottom, 
  

   33.3° 
  F. 
  

  

  Gloucester 
  Donation 
  803, 
  western 
  edge 
  of 
  Grand 
  Bank, 
  schooner 
  

   Gatherer, 
  August 
  16, 
  1881. 
  

  

  Characteristics. 
  — 
  Smooth, 
  firm 
  skin 
  of 
  pearl 
  gray 
  color, 
  lustrous 
  in 
  

   some 
  specimens. 
  Introvert 
  brownish-gray 
  in 
  alcoholic 
  specimens. 
  

   Four 
  retractors, 
  no 
  hooks 
  on 
  the 
  introvert, 
  no 
  eye-spots. 
  It 
  can 
  

   readily 
  be 
  distinguished 
  from 
  Ph. 
  gouldii 
  by 
  the 
  continuous 
  layer 
  of 
  

   circular 
  muscles 
  of 
  the 
  body 
  wall 
  and 
  by 
  the 
  shortness 
  and 
  greater 
  

   thickness 
  of 
  the 
  trunk. 
  

  

  In 
  form 
  and 
  proportion 
  (pi. 
  58, 
  fig. 
  1) 
  it 
  resembles 
  Ph. 
  eremita 
  

   (Sars), 
  and 
  especially 
  smooth 
  and 
  lustrous 
  specimens 
  of 
  the 
  latter 
  

   without 
  internal 
  examination 
  might 
  be 
  mistaken 
  for 
  this 
  species, 
  

   but 
  Ph. 
  eremita 
  has 
  a 
  rougher 
  skin, 
  marked 
  with 
  parallel 
  ridges 
  and 
  

   furrows 
  especially 
  evident 
  at 
  the 
  posterior 
  extremity 
  of 
  the 
  body, 
  

   and 
  the 
  trunk 
  is 
  usually 
  brownish, 
  rather 
  than 
  pearl-gray. 
  The 
  two 
  

   species 
  can 
  be 
  readily 
  distinguished 
  otherwise 
  by 
  the 
  fact 
  that 
  Ph. 
  

   margaritaceum 
  has 
  four 
  retractor 
  muscles. 
  Ph. 
  eremita 
  two. 
  

  

  Distribution. 
  — 
  Theel 
  (1905) 
  describes 
  Ph. 
  margaritaceum 
  as 
  a 
  true 
  

   Arctic 
  form, 
  possibly 
  with 
  a 
  circumpolar 
  distribution. 
  A 
  western 
  

   variety 
  occurs 
  off 
  Greenland, 
  Spitzbergen, 
  Norway 
  (Finmarken), 
  

   Russia 
  (Kola 
  Peninsula), 
  and 
  Nova 
  Zembla; 
  an 
  eastern 
  variety 
  is 
  

   found 
  north 
  of 
  Siberia 
  and 
  in 
  Bering 
  Strait. 
  

  

  It 
  is 
  much 
  less 
  abundant 
  off 
  the 
  coast 
  of 
  North 
  America 
  than 
  

   Ph. 
  eremita 
  (Sars), 
  but 
  occurs 
  at 
  depths 
  from 
  30 
  to 
  75 
  fathoms 
  off 
  

   Newfoundland 
  and 
  the 
  Canadian 
  coast. 
  

  

  