﻿MARINE 
  POLYCHAETE 
  WORMS 
  — 
  PETTIBONE 
  299 
  

  

  usually 
  concave 
  dorsally/witli''pair^of 
  small 
  ventral 
  eyes 
  and 
  pair 
  of 
  

   crescent-shaped 
  nuchal 
  slits 
  behind 
  eyes 
  (best 
  seen 
  from 
  lateral 
  view) 
  , 
  

   Thoracic 
  region 
  smooth, 
  without 
  reticulated 
  integument, 
  consisting 
  

   of 
  first 
  9 
  setigerous 
  segments, 
  each 
  of 
  first 
  7 
  with 
  four 
  bundles 
  of 
  

   capUlary 
  setae 
  which 
  on 
  setiger 
  7 
  may 
  be 
  only 
  capillaries, 
  only 
  crotch- 
  

   ets, 
  or 
  both 
  (in 
  young 
  specimens, 
  crotchets 
  may 
  be 
  present 
  from 
  

   setiger 
  4) 
  . 
  Setigers 
  8 
  and 
  9 
  modified, 
  having 
  neuropodia 
  with 
  row 
  of 
  

   hooded 
  crotchets, 
  and 
  with 
  large, 
  recurved, 
  amber-colored 
  acicular 
  

   genital 
  hooks 
  located 
  middorsally 
  between 
  these 
  two 
  segments. 
  

   Abdominal 
  segments 
  with 
  slightly 
  raised 
  dorsal 
  and 
  ventral 
  para- 
  

   podial 
  tori 
  each 
  bearing 
  a 
  row 
  of 
  hooded 
  crotchets. 
  Without 
  spe- 
  

   cialized 
  branchiae 
  or 
  lateral 
  organs. 
  Pygidium 
  a 
  short 
  ring, 
  may 
  be 
  

   inflated. 
  Color: 
  In 
  alcohol: 
  Without 
  color 
  or 
  reddish 
  brown. 
  

   Females 
  with 
  large 
  yolky 
  eggs 
  (Point 
  Barrow, 
  August 
  9, 
  30, 
  1949; 
  

   September 
  1, 
  6, 
  1949.) 
  

  

  Remarks. 
  — 
  According 
  to 
  Fauvel 
  and 
  others, 
  in 
  C. 
  capitata 
  the 
  genital 
  

   hooks 
  on 
  setigers 
  8 
  and 
  9 
  are 
  present 
  only 
  in 
  the 
  males, 
  the 
  females 
  

   having 
  only 
  crotchets. 
  On 
  all 
  the 
  specimens 
  from 
  Point 
  Barrow, 
  

   genital 
  hooks 
  are 
  present, 
  including 
  some 
  females 
  containing 
  large 
  

   yolky 
  eggs. 
  They 
  agree 
  in 
  all 
  other 
  respects 
  with 
  C. 
  capitata. 
  Having 
  

   genital 
  hooks 
  in 
  both 
  males 
  and 
  females, 
  they 
  would 
  fall 
  under 
  the 
  

   very 
  closely 
  related 
  Capitellides 
  Mesnil. 
  They 
  differ 
  from 
  C. 
  giardi 
  

   Mesnil 
  in 
  the 
  larger 
  number 
  of 
  genital 
  hooks. 
  They 
  are 
  herein 
  re- 
  

   ferred 
  to 
  the 
  cosmopolitan 
  C. 
  capitata 
  with 
  the 
  tentative 
  idea 
  that 
  the 
  

   relative 
  development 
  of 
  genital 
  hooks 
  in 
  the 
  female 
  may 
  prove 
  to 
  be 
  

   a 
  variable 
  character. 
  

  

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

   Point 
  Barrow, 
  6.6 
  fms.; 
  off 
  Point 
  Barrow 
  base, 
  up 
  to 
  7.5 
  miles 
  from 
  

   shore, 
  23.3-70 
  fms., 
  on 
  bottoms 
  of 
  stones 
  and 
  various 
  combinations 
  

   of 
  gravel, 
  stones, 
  rocks, 
  large 
  perforated 
  rocks 
  (8 
  stations, 
  26 
  speci- 
  

   mens). 
  Bering 
  Sea: 
  St. 
  Paul 
  Island, 
  Pribilofs, 
  in 
  holdfasts 
  with 
  

   Fabricia 
  sabella 
  and 
  lumbrinerids, 
  W. 
  L. 
  Hahn, 
  1911. 
  West 
  Coast 
  

   North 
  America: 
  Corona 
  del 
  Mar, 
  California, 
  from 
  branchial 
  cavity 
  

   of 
  crab, 
  Loxorhynchus 
  grandis, 
  MacGinitie, 
  1948. 
  East 
  Coast 
  North 
  

   America: 
  Off 
  Labrador, 
  6 
  fms., 
  mud-sand. 
  Blue 
  Dolphin 
  Expedition, 
  

   1949; 
  off 
  Massachusetts, 
  15 
  fms., 
  U. 
  S. 
  Fish 
  Commission; 
  Woods 
  Hole 
  

   region, 
  Massachusetts, 
  Pettibone, 
  1951. 
  

  

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

   and 
  Canadian 
  Arctic, 
  Davis 
  Strait, 
  Greenland, 
  Spitsbergen, 
  Novaya 
  

   Zemlya, 
  Kara 
  Sea. 
  Also 
  Iceland, 
  Faroes, 
  Norway 
  to 
  France, 
  Madeira, 
  

   Mediterranean, 
  Black 
  Sea; 
  Hudson 
  Bay 
  to 
  North 
  Carolina, 
  Texas; 
  

   Bering 
  Sea 
  to 
  southern 
  California; 
  north 
  Japan 
  Sea. 
  Southern 
  lati- 
  

   tudes 
  : 
  Magellan 
  Straits, 
  South 
  Georgia, 
  Bouvet 
  Island, 
  South 
  Africa, 
  

   Kerguelen. 
  In 
  low 
  water 
  to 
  500 
  fathoms. 
  

  

  261112—54 
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