﻿294 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  103 
  

  

  oped 
  ventral 
  groove 
  along 
  length 
  of 
  body, 
  better 
  developed 
  in 
  posterior 
  

   region. 
  Integument 
  tesselated, 
  with 
  four 
  annuli 
  per 
  segment. 
  Pro- 
  

   stomium 
  subquadrangular, 
  wider 
  anteriorly, 
  with 
  frontal 
  horns 
  on 
  

   anterolateral 
  borders, 
  with 
  pair 
  of 
  evaginable 
  nuchal 
  organs 
  lateral 
  

   to 
  prostomium 
  (when 
  inverted, 
  appear 
  as 
  diagonal 
  slits). 
  Buccal 
  

   segment 
  achaetous, 
  forming 
  rugose 
  ring 
  around 
  prostomium. 
  Mouth 
  

   ventral, 
  at 
  level 
  of 
  first 
  setigerous 
  lobes. 
  Proboscis 
  eversible, 
  globular, 
  

   smooth, 
  unarmed. 
  Branchiae 
  four 
  pairs, 
  short, 
  tufted, 
  arborescent, 
  

   inserted 
  posterior 
  to 
  notopodia 
  on 
  setigers 
  2-5, 
  increasing 
  in 
  size 
  

   posteriorly. 
  Noto- 
  and 
  neuropodial 
  lobes 
  of 
  anterior 
  segments 
  small, 
  

   projecting, 
  subequal. 
  Beginning 
  on 
  setigers 
  16-18, 
  dorsal 
  and 
  ventral 
  

   cirri 
  develop 
  gradually, 
  becoming 
  elongate-conical, 
  flattened 
  or 
  

   inflated. 
  Setae 
  silky, 
  iridescent, 
  capillary 
  (may 
  be 
  extra 
  long 
  in 
  

   epitokous 
  pelagic 
  form). 
  Lateral 
  ciliated 
  organs 
  between 
  rami. 
  

   Pygidium 
  with 
  five^o 
  seven, 
  short 
  to 
  long, 
  deciduous, 
  filiform 
  anal 
  

   cirri 
  on 
  ventral 
  side. 
  Epitokous 
  sexual 
  forms 
  may 
  appear 
  in 
  surface 
  

   waters, 
  massed 
  with 
  sexual 
  products, 
  with 
  extra 
  long 
  setae 
  and 
  

   usually 
  with 
  highly 
  pigmented 
  dorsal 
  and 
  ventral 
  cirri. 
  Color: 
  

   In 
  life 
  : 
  Orange 
  yellow. 
  In 
  alcohol 
  : 
  Without 
  color, 
  orange 
  yellow, 
  or 
  

   sulfur 
  yellow 
  with 
  darker 
  pigmented 
  masses 
  in 
  the 
  outer 
  portions 
  of 
  

   the 
  dorsal 
  and 
  ventral 
  cirri. 
  

  

  Remarks. 
  — 
  Scalibregma 
  brevicauda 
  Verrill 
  is 
  herein 
  referred 
  to 
  S. 
  

   injlatum. 
  Although 
  the 
  types 
  were 
  not 
  examined, 
  specimens 
  from 
  

   the 
  New 
  England 
  region 
  identified 
  by 
  Verrill 
  as 
  S. 
  brevicauda 
  were 
  

   observed. 
  The 
  types 
  of 
  S. 
  minutum 
  Webster 
  and 
  Benedict 
  from 
  

   Eastport, 
  Maine, 
  were 
  examined 
  and 
  found 
  to 
  agree 
  with 
  S. 
  injlatum. 
  

  

  New 
  records. 
  — 
  Arctic 
  Alaska: 
  Point 
  Barrow 
  base, 
  washed 
  ashore; 
  

   off 
  Point 
  Barrow 
  base, 
  22.5-78 
  fms,, 
  up 
  to 
  15 
  miles 
  from 
  shore, 
  on 
  

   bottoms 
  of 
  mud 
  and 
  various 
  combinations 
  of 
  mud, 
  sand, 
  gravel, 
  

   stones, 
  rocks, 
  with 
  shells 
  and 
  worm 
  tubes 
  (9 
  stations, 
  17 
  specimens). 
  

   West 
  Coast 
  North 
  America: 
  Washington 
  and 
  Puget 
  Sounds, 
  25 
  

   fms., 
  mud, 
  Pettibotie. 
  East 
  Coast 
  North 
  America: 
  Off 
  Labrador, 
  

   17-35 
  fms.. 
  Blue 
  Dolphin 
  Expeditions, 
  1950, 
  1951; 
  off 
  Nova 
  Scotia, 
  

   Maine, 
  Massachusetts, 
  Rhode 
  Island, 
  Connecticut, 
  Long 
  Island 
  

   Sound, 
  5-95.5 
  fms., 
  U. 
  S. 
  Fish 
  Commission; 
  Cuttyhunk, 
  Massachu- 
  

   setts, 
  low 
  water, 
  in 
  sand, 
  Pettibone, 
  1950. 
  

  

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

   and 
  Canadian 
  Arctic, 
  Davis 
  Strait, 
  Greenland, 
  Jan 
  Mayen, 
  Spits- 
  

   bergen, 
  Franz 
  Josef 
  Land, 
  Novaya 
  Zemlya, 
  Kara 
  Sea. 
  Also 
  Iceland, 
  

   Faroes, 
  Norway 
  to 
  France, 
  Adriatic, 
  Gulf 
  of 
  Oman; 
  Labrador 
  to 
  

   Long 
  Island 
  Sound; 
  Bering 
  Sea 
  to 
  central 
  California; 
  north 
  Japan 
  

   Sea 
  to 
  Japan. 
  Southern 
  latitudes: 
  New 
  Zealand, 
  Magellan 
  Straits, 
  

   South 
  Georgia, 
  Prince 
  Edward 
  Islands, 
  Kerguelen. 
  In 
  low 
  water 
  to 
  

   1,333 
  fathoms; 
  epitokes 
  at 
  surface. 
  

  

  