﻿336 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  103 
  

  

  Augener, 
  1928, 
  p. 
  801.— 
  Hartman, 
  1942a, 
  p. 
  81; 
  1944a, 
  pp. 
  336, 
  343; 
  

  

  1948, 
  p. 
  46.— 
  Zatsepin, 
  1948, 
  p. 
  162, 
  pi. 
  39, 
  fig. 
  7.— 
  Wesenberg-Lund, 
  1950a, 
  

  

  p. 
  56; 
  1950b, 
  p. 
  128; 
  1951, 
  p. 
  119.— 
  Berkeley 
  and 
  Berkeley, 
  1952, 
  p. 
  116, 
  fig. 
  

  

  238. 
  

   Potamilla 
  torelli 
  Malmgren, 
  1865, 
  p. 
  402; 
  1867, 
  p. 
  114, 
  pi. 
  13, 
  fig. 
  76.— 
  Ehlers, 
  

  

  1913, 
  p. 
  575.— 
  Fauvel, 
  1927, 
  p. 
  310, 
  fig. 
  107, 
  m-s; 
  1934a, 
  p. 
  71.— 
  Annenkova, 
  

  

  1934, 
  p. 
  322; 
  1937, 
  p. 
  195; 
  1938, 
  p. 
  213.— 
  Wesenberg-Lund, 
  1951, 
  p. 
  121. 
  

   Potamilla 
  acuminata 
  Moore 
  and 
  Bush, 
  1904, 
  p. 
  159, 
  pi. 
  11, 
  figs. 
  3-6; 
  pi. 
  12, 
  fig. 
  

  

  41. 
  

  

  Description. 
  — 
  Length 
  30-84 
  mm., 
  1-3 
  mm. 
  wide. 
  Collarette 
  widely- 
  

   separated 
  dorsally, 
  sloping 
  ventrally, 
  with 
  midventral 
  slit, 
  entire 
  

   laterally, 
  resulting 
  in 
  a 
  2-lobed 
  structure; 
  ventral 
  lobes 
  triangular, 
  

   may 
  be 
  deflected. 
  Branchial 
  lobes 
  each 
  with 
  about 
  16 
  filaments 
  

   (6-20), 
  with 
  short, 
  naked 
  distal 
  tips, 
  without 
  eyes. 
  Thoracic 
  setigers 
  

   usually 
  8 
  (5-8). 
  Pygidium 
  with 
  pair 
  of 
  bulbous 
  lobes 
  with 
  dark 
  eye- 
  

   spots. 
  Color: 
  In 
  alcohol: 
  Body 
  colorless, 
  branchiae 
  with 
  two 
  or 
  

   three 
  difiFused 
  reddish 
  brown 
  bands. 
  Tube: 
  Horny, 
  transparent, 
  

   more 
  or 
  less 
  covered 
  with 
  sand 
  or 
  mud; 
  smaller 
  tubes 
  with 
  rather 
  

   uniform 
  layer 
  of 
  small 
  sand 
  grains; 
  larger 
  tubes 
  may 
  be 
  encrusted 
  

   with 
  living 
  barnacles, 
  bryozoans, 
  hydroids, 
  foraminiferans, 
  amphipod 
  

   tubes. 
  Large 
  yolky 
  eggs 
  in 
  a 
  single 
  layer, 
  pressed 
  close 
  to 
  wall, 
  

   about 
  one-third 
  way 
  down 
  in 
  tube; 
  a 
  transparent, 
  thin 
  membrane 
  

   laid 
  down 
  between 
  eggs 
  and 
  worm 
  (large 
  developing 
  yellow 
  eggs 
  

   found 
  in 
  tube, 
  September 
  6, 
  1949, 
  dredged 
  in 
  36 
  fathoms. 
  Point 
  

   Barrow) 
  . 
  

  

  New 
  records. 
  — 
  Arctic 
  Alaska: 
  Off 
  Point 
  Barrow 
  base, 
  up 
  to 
  12.1 
  

   miles 
  from 
  shore, 
  21.7-123.5 
  fms., 
  on 
  bottoms 
  of 
  mass 
  of 
  worm 
  tubes 
  

   and 
  pebbles, 
  gravel, 
  rocks, 
  large 
  stones 
  (7 
  stations, 
  24 
  specimens). 
  

   Bering 
  Sea: 
  Albatross 
  Sta. 
  3496, 
  56°32' 
  N., 
  169°45' 
  W., 
  41 
  fms., 
  

   1893; 
  St. 
  Paul 
  Island, 
  Pribilofs, 
  Hahn, 
  1911. 
  Alaska: 
  Albatross 
  

   Sta., 
  Kodiak, 
  1888. 
  West 
  Greenland: 
  Off 
  Hare 
  Island, 
  70°20' 
  N., 
  

   56° 
  W., 
  90 
  fms., 
  U. 
  S. 
  S. 
  Alert, 
  1884. 
  East 
  Coast 
  North 
  America: 
  

   Off 
  Labrador, 
  125 
  fms., 
  Blue 
  Dolphin 
  Expedition, 
  1949; 
  off 
  Maine, 
  

   Massachusetts, 
  31-130 
  fms., 
  U. 
  S. 
  Fish 
  Commission. 
  

  

  Distribution. 
  — 
  Widely 
  distributed 
  in 
  the 
  Arctic: 
  Siberian 
  and 
  

   Alaskan 
  Arctic, 
  Greenland, 
  Spitsbergen. 
  Also 
  Iceland, 
  Faroes, 
  Nor- 
  

   way 
  to 
  France, 
  Madeira, 
  Mediterranean, 
  Adriatic, 
  Cape 
  Verde 
  

   Islands; 
  Labrador 
  to 
  Massachusetts; 
  Bering 
  Sea 
  to 
  California; 
  north 
  

   Japan 
  Sea 
  to 
  Japan; 
  Antarctic. 
  In 
  low 
  water 
  to 
  1,044 
  fathoms. 
  

  

  Potamilla 
  reniformis 
  (Leuckart, 
  1849) 
  

  

  Figure 
  38, 
  o-u 
  

  

  Sabella 
  reniformis 
  Leuckart, 
  1849, 
  p. 
  183, 
  pi. 
  3, 
  fig. 
  8. 
  

  

  Potamilla 
  reniformis 
  Malmgren, 
  1867, 
  p. 
  114, 
  pi. 
  13, 
  fig. 
  77. 
  — 
  Webster 
  and 
  Bene- 
  

   dict, 
  1884, 
  p. 
  736; 
  1887, 
  p. 
  750.— 
  Johansson, 
  1927, 
  p. 
  142.— 
  Fauvel, 
  1927, 
  

  

  