﻿252 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  103 
  

  

  comutus 
  as 
  to 
  size, 
  about 
  one-third 
  the 
  size 
  of 
  the 
  sexual 
  stage 
  of 
  A. 
  

   prismaticus, 
  and 
  in 
  the 
  absence 
  of 
  semicircular 
  epaulettes 
  (specimens 
  

   examined 
  through 
  the 
  kindness 
  of 
  the 
  Berkeleys). 
  The 
  record 
  of 
  A. 
  

   prismaticus 
  from 
  Oregon 
  by 
  Hartman 
  and 
  Reish 
  (1950) 
  is 
  doubted 
  

   since 
  it 
  is 
  based 
  on 
  male 
  stolons 
  only. 
  

  

  New 
  records. 
  — 
  Arctic 
  Alaska: 
  Eluitkak 
  Pass, 
  Elson 
  Lagoon 
  near 
  

   Point 
  Barrow, 
  6.6 
  fms., 
  stony-mud; 
  off 
  Point 
  Barrow 
  base, 
  5-70 
  fms., 
  

   up 
  to 
  7 
  miles 
  from 
  shore, 
  on 
  bottoms 
  of 
  stones, 
  and 
  various 
  combina- 
  

   tions 
  of 
  mud, 
  gravel, 
  stones 
  (7 
  stations, 
  11 
  specimens). 
  East 
  Coast 
  

   North 
  America: 
  Lagoon 
  Pond, 
  Martha's 
  Vineyard, 
  Massachusetts, 
  

   pile 
  scrapings, 
  Pettibone, 
  1951. 
  

  

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

   and 
  Canadian 
  Arctic, 
  Greenland, 
  Spitsbergen, 
  Barents 
  Sea, 
  Novaya 
  

   Zemlya. 
  Also 
  Iceland; 
  Labrador 
  to 
  Massachusetts; 
  Bering 
  Sea 
  to 
  

   British 
  Columbia 
  ( 
  ? 
  Oregon) 
  ; 
  north 
  Japan 
  Sea. 
  In 
  low 
  water 
  to 
  267 
  

   fathoms; 
  sexual 
  forms 
  at 
  surface. 
  

  

  Genus 
  Syllis 
  Savigny, 
  1818 
  

  

  Both 
  species 
  represented 
  have 
  the 
  body 
  elongate, 
  slender, 
  with 
  

   numerous 
  segments, 
  flattened 
  ventrally, 
  arched 
  dorsally, 
  tapering 
  

   slightly 
  anteriorly 
  and 
  gradually 
  posteriorly. 
  Prostomium 
  oval, 
  wider 
  

   than 
  long; 
  two 
  palps 
  wider 
  basally, 
  well 
  separated 
  except 
  where 
  their 
  

   inner 
  basal 
  sides 
  are 
  fused 
  (fig. 
  28, 
  c). 
  Dorsal 
  cirri 
  distinctly 
  monili- 
  

   form 
  throughout 
  body, 
  alternately 
  slightly 
  longer 
  and 
  shorter. 
  Ven- 
  

   tral 
  cirri 
  digitiform, 
  slightly 
  shorter 
  or 
  longer 
  than 
  the 
  parapodial 
  

   lobes 
  (fig. 
  28, 
  d). 
  Anterior 
  end 
  of 
  extended 
  proboscis 
  with 
  a 
  smooth, 
  

   chitinous 
  rim, 
  a 
  single 
  large, 
  grayish 
  dorsal 
  tooth, 
  with 
  a 
  ring 
  of 
  short, 
  

   thick 
  papillae, 
  with 
  a 
  ring 
  of 
  10 
  shorter 
  papiUae 
  more 
  basally. 
  Male 
  

   and 
  female 
  stolons 
  or 
  epitokous 
  forms 
  (Chaetosyllis 
  Malmgren, 
  1867) 
  

   developed 
  from 
  the 
  posterior 
  segments 
  of 
  the 
  body; 
  when 
  fully 
  

   developed 
  consisting 
  of 
  small 
  bilobed 
  (or 
  tetralobed) 
  bulbous 
  "head" 
  

   with 
  two 
  pairs 
  of 
  eyes, 
  a 
  dorsal 
  pair 
  and 
  a 
  larger 
  ventral 
  pair, 
  with 
  

   a 
  pair 
  of 
  short 
  moniliform 
  antennae 
  ; 
  the 
  first 
  setigerous 
  segment 
  with 
  

   neurosetae 
  only, 
  followed 
  by 
  a 
  variable 
  number 
  of 
  segments 
  with 
  

   additional 
  long 
  capillary 
  swimming 
  setae 
  and 
  usually 
  a 
  few 
  unmodified 
  

   posterior 
  segments; 
  stolons 
  greatly 
  distended 
  with 
  developing 
  sex 
  

   products; 
  neurosetae, 
  dorsal, 
  ventral 
  and 
  anal 
  cirri 
  similar 
  to 
  those 
  

   of 
  stem 
  form. 
  

  

  Key 
  to 
  the 
  species 
  of 
  Syllis 
  from 
  Point 
  Barrow 
  

  

  1. 
  Compound 
  neurosetae 
  with 
  short 
  and 
  long 
  distal 
  blades 
  (fig. 
  28, 
  /). 
  Acicula 
  

   of 
  parapodia 
  not 
  particularly 
  enlarged 
  or 
  protruding. 
  Body 
  segments 
  very 
  

   short 
  S. 
  cornuta 
  

  

  Compound 
  neurosetae 
  with 
  terminal 
  blades 
  differing 
  very 
  slightly 
  in 
  length 
  

   (fig. 
  28, 
  e) 
  . 
  From 
  1 
  to 
  4 
  very 
  large 
  acicula 
  usually 
  protrude 
  somewhat 
  from 
  

   parapodial 
  tip 
  (fig. 
  28, 
  d). 
  Body 
  segments 
  longer 
  S. 
  fasciata 
  

  

  