﻿324 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  103 
  

  

  Pista 
  maculata 
  Hessle, 
  1917, 
  p. 
  161, 
  pi. 
  3, 
  fig. 
  4. 
  — 
  Fauvel, 
  1927, 
  p. 
  263, 
  fig. 
  91, 
  

   a-h. 
  — 
  Berkeley 
  and 
  Berkeley, 
  1943, 
  p. 
  130, 
  — 
  Gorbunov, 
  1946, 
  p. 
  39. 
  — 
  

   Zatsepin, 
  1948, 
  p. 
  155, 
  pi. 
  38, 
  fig. 
  9.— 
  Wesenberg-Lund, 
  1950a, 
  p. 
  52; 
  1950b, 
  

   p. 
  119; 
  1951, 
  p. 
  110. 
  

  

  Pista 
  groenlandica 
  Treadwell, 
  1937, 
  p. 
  33, 
  figs. 
  14-16. 
  

  

  Description. 
  — 
  ^Length 
  up 
  to 
  150 
  mm., 
  width 
  6 
  mm. 
  Ventral 
  shields 
  

   about 
  14. 
  Cephalic 
  ridge 
  with 
  numerous 
  eye-spots. 
  Single 
  pair 
  

   large 
  branchiae 
  on 
  segment 
  2, 
  with 
  large, 
  cylindrical 
  main 
  trunk, 
  

   branched. 
  Buccal 
  segment 
  with 
  two 
  large, 
  rounded 
  lateral 
  lobes 
  

   embracing 
  prostomium, 
  connected 
  ventrally 
  by 
  a 
  crest; 
  segment 
  2 
  

   short, 
  without 
  lateral 
  lobes; 
  segment 
  3 
  with 
  large, 
  rounded, 
  flattened 
  

   lateral 
  lobes. 
  Nephridial 
  papillae 
  on 
  segments 
  6-7. 
  Thoracic 
  

   setigers 
  16 
  (one 
  had 
  small 
  lobe 
  on 
  one 
  side 
  only 
  on 
  17). 
  Uncini 
  

   begin 
  on 
  segment 
  5 
  (setiger 
  2), 
  in 
  single 
  rows 
  on 
  first 
  6, 
  in 
  two 
  alternat- 
  

   ing 
  intercogging 
  rows 
  on 
  rest 
  of 
  thoracic 
  segments, 
  in 
  single 
  rows 
  on 
  

   rectangular 
  pinnules 
  in 
  abdominal 
  region. 
  Pygidium 
  with 
  six 
  or 
  

   seven 
  (6-12) 
  conical 
  papillae, 
  arranged 
  starlike. 
  Color: 
  In 
  alcohol: 
  

   Branchiae 
  and 
  tentacles 
  dark 
  brown 
  or 
  colorless. 
  Tubes: 
  Irregularly 
  

   twisted, 
  with 
  thin 
  transparent 
  membranous 
  lining 
  covered 
  mostly 
  

   with 
  fine 
  sand 
  grains 
  plus 
  few 
  large 
  pebbles, 
  bits 
  of 
  shell, 
  bryozoans, 
  

   foraminiferans, 
  algae, 
  parts 
  of 
  other 
  worm 
  tubes. 
  

  

  Remarks. 
  — 
  The 
  type 
  of 
  P. 
  groenlandica 
  Treadwell 
  from 
  Baflin 
  Bay 
  

   was 
  examined 
  and 
  is 
  herein 
  referred 
  to 
  P. 
  maculata. 
  Contrary 
  to 
  the 
  

   original 
  description, 
  eye-spots 
  are 
  present 
  on 
  the 
  cephalic 
  ridge 
  (small, 
  

   in 
  transverse 
  groove, 
  easily 
  overlooked) 
  . 
  

  

  New 
  records. 
  — 
  Arctic 
  Alaska: 
  Off 
  Point 
  Barrow 
  base, 
  up 
  to 
  15 
  

   miles 
  from 
  shore, 
  21-123.5 
  fms., 
  on 
  bottoms 
  of 
  mass 
  of 
  worm 
  tubes 
  

   and 
  various 
  combinations 
  of 
  mud, 
  gravel, 
  stones, 
  rocks, 
  large 
  per- 
  

   forated 
  rocks; 
  from 
  crab, 
  Hyas 
  coarctatus 
  (13 
  stations, 
  168 
  plus 
  speci- 
  

   mens). 
  North 
  Greenland: 
  5 
  miles 
  south 
  Cape 
  Chalon; 
  north 
  

   Omenolu 
  near 
  North 
  Star 
  Bay, 
  17 
  fms., 
  Bartlett, 
  1932. 
  West 
  

   Greenland: 
  Oelrichs 
  Bay, 
  1937; 
  off 
  Conical 
  Kock, 
  76°3' 
  N., 
  67°30' 
  

   W., 
  20-40 
  fms., 
  1938; 
  1 
  mile 
  northwest 
  Conical 
  Rock, 
  25-60 
  fms., 
  

   1940; 
  between 
  north 
  shores 
  Parkers 
  Snow 
  Bay 
  and 
  Conical 
  Rock, 
  

   25-45 
  fms., 
  1940; 
  aU 
  collected 
  by 
  Bartlett. 
  East 
  Greenland: 
  Off 
  

   Cape 
  Hold 
  with 
  Hope, 
  23^0 
  fms., 
  Bartlett, 
  1939. 
  East 
  Coast 
  

   North 
  America 
  : 
  Off 
  Labrador, 
  8-125 
  fms.. 
  Blue 
  Dolphin 
  Expeditions, 
  

   1949, 
  1950, 
  1951. 
  

  

  Distribution. 
  — 
  Widely 
  distributed 
  in 
  the 
  Arctic: 
  Siberian, 
  Alaskan, 
  

   and 
  Canadian 
  Arctic, 
  Baffin 
  Bay, 
  Greenland, 
  Spitsbergen, 
  Barent 
  

   Sea, 
  Novaya 
  Zemlya. 
  Also 
  Iceland, 
  Norway 
  to 
  English 
  Channel: 
  

   Hudson 
  Bay 
  to 
  Maine; 
  Bering 
  Sea. 
  In 
  3-1,528 
  fathoms. 
  

  

  