﻿318 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  103 
  

  

  GerkusAsabellides 
  Annenkova, 
  1929 
  

  

  Includes 
  Pseudosahellides 
  Berkeley 
  and 
  Berkeley, 
  1943. 
  

  

  Asabellides 
  sibirica 
  (Wiren, 
  1883) 
  

  

  Figure 
  36, 
  e 
  

  

  Sabellides 
  sibirica 
  Wir6n, 
  1883, 
  p. 
  418. 
  

  

  Asabellides 
  orientalis 
  Annenkova, 
  1929, 
  p. 
  494, 
  pi. 
  38, 
  figs. 
  50, 
  51, 
  pi. 
  39, 
  figs. 
  

  

  60-65; 
  1937, 
  p. 
  188. 
  

   Asabellides 
  sibirica 
  Annenkova, 
  1938, 
  p. 
  201. 
  

   Pseudosabellides 
  lineata 
  Berkeley 
  and 
  Berkeley, 
  1943, 
  p. 
  131; 
  1944, 
  p. 
  3; 
  1952, 
  

  

  p. 
  71, 
  fig. 
  147. 
  

  

  Description. 
  — 
  Body 
  long, 
  slender, 
  38 
  mm. 
  long, 
  1.5 
  mm. 
  wide. 
  

   Prostomium 
  trilobed 
  with 
  median 
  lobe 
  wider 
  and 
  flared 
  anteriorly, 
  

   lateral 
  lobes 
  diagonal. 
  Segments 
  1 
  and 
  2 
  fused 
  laterally 
  and 
  ventrally, 
  

   forming 
  large 
  lower 
  lip; 
  dorsally, 
  appear 
  as 
  two 
  short 
  segments 
  more 
  

   or 
  less 
  hidden 
  by 
  dorsal 
  branchial 
  fold. 
  Segments 
  3 
  and 
  4 
  more 
  or 
  less 
  

   fused 
  ventrally 
  and 
  laterally; 
  dorsally, 
  segment 
  3 
  without 
  paleae 
  but 
  

   with 
  branchiae; 
  segment 
  4 
  with 
  first 
  notopodial 
  lobes 
  and, 
  middorsally, 
  

   a 
  fused 
  nephridial 
  area 
  wath 
  pair 
  of 
  papillae 
  posterior 
  to 
  branchial 
  

   bases. 
  Branchiae 
  slender, 
  fihform, 
  emerge 
  from 
  prominent 
  ridge, 
  six 
  

   in 
  transverse 
  row, 
  two 
  slightly 
  posterior. 
  Abdominal 
  segments 
  23 
  

   (14-23). 
  Neuropodial 
  cirri 
  smaU, 
  short, 
  rounded 
  (Point 
  Barrow 
  

   specimens) 
  to 
  long, 
  slender, 
  cirriform. 
  Pygidium 
  with 
  few 
  small 
  cirri 
  

   and 
  pair 
  of 
  long 
  lateral 
  ones. 
  Color: 
  In 
  life: 
  Salmon 
  below, 
  darker 
  

   above, 
  branchiae 
  green, 
  oral 
  tentacles 
  pink. 
  In 
  alcohol: 
  Colorless. 
  

  

  New 
  records. 
  — 
  Arctic 
  Alaska: 
  Off 
  Point 
  Barrow 
  base, 
  5 
  mUes 
  from 
  

   shore, 
  11.7 
  fms., 
  on 
  bottom 
  of 
  mud 
  (1 
  station, 
  3 
  specimens). 
  

  

  Distribution. 
  — 
  Scattered 
  records 
  in 
  the 
  Arctic: 
  Siberian, 
  Alaskan, 
  

   and 
  Canadian 
  Arctic. 
  Also 
  Hudson 
  Bay; 
  Bering 
  Sea 
  to 
  British 
  

   Columbia; 
  Okhotsk 
  Sea 
  to 
  north 
  Japan 
  Sea. 
  In 
  4-106 
  fathoms. 
  

  

  Family 
  Terebellidae 
  

  

  Body 
  divided 
  into 
  two 
  regions: 
  (1) 
  thoracic; 
  more 
  or 
  less 
  inflated, 
  

   with 
  dorsal 
  bimdles 
  of 
  capillary 
  setae 
  and 
  ventral 
  uncinigerous 
  tori 
  

   (sometimes 
  acicular 
  crotchets, 
  sometimes 
  absent), 
  often 
  with 
  ventral 
  

   glandular 
  shields; 
  (2) 
  abdominal; 
  elongated, 
  more 
  or 
  less 
  tapering, 
  

   most 
  often 
  lacking 
  dorsal 
  setae 
  and 
  bearing 
  only 
  uncinigerous 
  pinnules. 
  

   Prostomium 
  of 
  variable 
  form 
  and 
  dimensions, 
  fused 
  with 
  buccal 
  seg- 
  

   ment, 
  forming 
  a 
  lower 
  lip, 
  a 
  transverse 
  dorsal 
  cephalic 
  ridge 
  with 
  or 
  

   without 
  numerous 
  eye-spots, 
  a 
  tentacular 
  membrane 
  with 
  numerous 
  

   filiform 
  grooved 
  tentacles 
  not 
  retractile 
  in 
  mouth, 
  a 
  semicircular 
  or 
  

   folded 
  upper 
  lip 
  (fig. 
  36,/). 
  Branchiae 
  1-3 
  pairs, 
  filiform 
  or 
  arbores- 
  

   cent, 
  or 
  single, 
  quadrilobed, 
  pectinate, 
  on 
  anterior 
  segments, 
  or 
  

  

  