﻿278 
  PROCEEDINGS 
  OP 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  i03 
  

  

  conical, 
  without 
  appendages. 
  Two 
  wide 
  peristomial 
  segments, 
  the 
  

   second 
  with 
  wide 
  transverse 
  ciliated 
  band. 
  Setigerous 
  segments 
  8, 
  

   gradually 
  tapering 
  posteriorly, 
  each 
  parapodium 
  with 
  single 
  limbate 
  

   capillary 
  seta 
  and 
  hooded 
  seta. 
  Pygidium 
  bulbous, 
  with 
  wide 
  trans- 
  

   verse 
  ciliated 
  band. 
  

  

  Family 
  Orbiniidae 
  (Ariciidae) 
  

  

  Body 
  long, 
  vermiform, 
  with 
  very 
  numerous 
  segments, 
  divided 
  into 
  

   two 
  weakly 
  to 
  sharply 
  separable 
  regions: 
  (1) 
  thoracic: 
  More 
  or 
  less 
  

   flattened 
  dorsoventrally 
  and 
  enlarged; 
  attenuated 
  anteriorly; 
  neuro- 
  

   podia 
  cushionlike, 
  with 
  several 
  rows 
  of 
  setae; 
  notopodia 
  more 
  or 
  less 
  

   cirriform, 
  a 
  bundle 
  of 
  crenulate 
  capillary 
  setae 
  (fig. 
  32, 
  6); 
  (2) 
  ab- 
  

   dominal: 
  Much 
  longer, 
  semicylindrical; 
  neuropodia 
  bilobed, 
  project- 
  

   ing 
  dorsally 
  (fig. 
  32, 
  c). 
  Branchiae 
  medial 
  to 
  notopodia, 
  simple, 
  

   dorsal, 
  erect, 
  lanceolate 
  or 
  straplike, 
  strongly 
  ciliated, 
  a 
  pair 
  on 
  aU 
  

   segments 
  except 
  the 
  anterior 
  ones. 
  Prostomium 
  conical 
  or 
  globular, 
  

   without 
  appendages, 
  with 
  or 
  without 
  two 
  small 
  eyes, 
  with 
  two 
  ciliated 
  

   nuchal 
  organs 
  (fig. 
  32, 
  a). 
  First 
  one 
  or 
  two 
  segments 
  apodous 
  and 
  

   achaetous. 
  Usually 
  without 
  dorsal 
  or 
  ventral 
  cirri. 
  Setae 
  simple, 
  of 
  

   varied 
  form. 
  Pygidium 
  with 
  two 
  to 
  four 
  anal 
  cirri. 
  Proboscis 
  

   eversible, 
  unarmed, 
  a 
  voluminous, 
  weakly- 
  to 
  much-branched, 
  soft 
  sac. 
  

  

  Represented 
  by 
  a 
  single 
  species 
  from 
  Point 
  Barrow. 
  

  

  Genus 
  Scoloplos 
  Blainville, 
  1828 
  

   Scoloplos 
  armiger 
  (O. 
  F. 
  Miiller, 
  1776) 
  

  

  Figure 
  32, 
  a-e 
  

  

  Lumhricus 
  armiger 
  O. 
  F. 
  MuUer, 
  1776, 
  p. 
  215; 
  1788, 
  p. 
  22, 
  pi. 
  22, 
  figs. 
  4, 
  5. 
  

  

  Aricia 
  arctica 
  Hansen, 
  1882, 
  p. 
  34, 
  pi. 
  5, 
  figs. 
  20-26. 
  — 
  Murdoch, 
  1885, 
  p. 
  154. 
  

  

  Scoloplos 
  armiger 
  Fauvel, 
  1914, 
  p. 
  224; 
  1927, 
  p. 
  20, 
  fig. 
  6, 
  k-g. 
  — 
  Eliason, 
  1920, 
  

   p. 
  39. 
  — 
  Augener, 
  1928, 
  p. 
  742.— 
  Monro, 
  1930, 
  p. 
  145. 
  — 
  Annenkova, 
  1931, 
  p. 
  

   203; 
  1937, 
  p. 
  169; 
  1938, 
  p. 
  170.— 
  Okuda, 
  1937a, 
  p. 
  102, 
  fig. 
  4.— 
  Wesenberg- 
  

   Lund, 
  1939b, 
  p. 
  12; 
  1950a, 
  p. 
  29; 
  1950b, 
  p. 
  73; 
  1951, 
  p. 
  58.— 
  Berkeley 
  and 
  

   Berkeley, 
  1942, 
  p. 
  195; 
  1952, 
  p. 
  97, 
  figs. 
  197-199.— 
  Hartman, 
  1944a, 
  pp. 
  336, 
  

   340, 
  pi. 
  18, 
  fig. 
  5 
  (not 
  pi. 
  19, 
  fig. 
  6 
  (=Orbinia)) 
  .—Thorson, 
  1946, 
  p. 
  78, 
  fig. 
  

   37.— 
  Gorbunov, 
  1946, 
  p. 
  39.— 
  Zatsepin, 
  1948, 
  p. 
  128, 
  pi. 
  32, 
  fig. 
  1. 
  

  

  Haploscoloplos 
  alaskensis 
  Hartman, 
  1948, 
  p. 
  30, 
  fig. 
  8, 
  a-c. 
  

  

  Description. 
  — 
  ^Length 
  up 
  to 
  120 
  mm., 
  width 
  2 
  mm. 
  Prostomium 
  

   conical, 
  pointed, 
  with 
  two 
  deeply 
  buried 
  eyes 
  (not 
  visible 
  when 
  pre- 
  

   served). 
  First 
  segment 
  achaetous 
  and 
  apodous. 
  Branchiae 
  first 
  

   appear 
  on 
  setigers 
  12 
  or 
  13 
  (9-17), 
  very 
  small 
  at 
  first, 
  then 
  triangular, 
  

   then 
  ligulate. 
  Thoracic 
  region 
  consisting 
  of 
  about 
  17 
  setigers 
  

   (12-20) 
  ; 
  notopodia 
  with 
  conical 
  postsetal 
  lobes 
  and 
  numerous, 
  finely 
  

   crenulate 
  setae 
  with 
  capillary 
  tips; 
  neuropodia 
  elongate, 
  cushionlike, 
  

   with 
  a 
  median 
  postsetal 
  conical 
  lobe, 
  with 
  numerous 
  rows 
  of 
  crenulate 
  

  

  