﻿248 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  los 
  

  

  head 
  of 
  the 
  bud 
  forming 
  between 
  setigers 
  13 
  and 
  14; 
  6 
  were 
  broken 
  

   after 
  setiger 
  13, 
  5 
  consisted 
  of 
  13 
  setigers 
  plus 
  a 
  definite 
  posterior 
  

   growing 
  zone, 
  and 
  12 
  consisted 
  of 
  36 
  setigers 
  or 
  less 
  and 
  showed 
  no 
  

   sign 
  of 
  bud 
  formation. 
  Of 
  the 
  45 
  specimens 
  showing 
  bud 
  formation, 
  

   18 
  were 
  young 
  buds 
  (sex?) 
  showing 
  four 
  eyes 
  and 
  rudiments 
  of 
  head 
  

   appendages; 
  17 
  were 
  developing 
  male 
  stolons 
  as 
  indicated 
  especially 
  

   by 
  the 
  developing 
  forked 
  palps 
  (at 
  first, 
  one 
  part 
  of 
  fork 
  about 
  one- 
  

   half 
  the 
  length 
  of 
  the 
  other), 
  large 
  median 
  antenna, 
  and 
  large 
  dorsal 
  

   tentacular 
  cirri; 
  the 
  male 
  buds 
  consisted 
  of 
  a 
  variable 
  number 
  of 
  

   setigers 
  (14-26 
  plus 
  a 
  definite 
  growing 
  zone, 
  or 
  32-42 
  and 
  tapered 
  

   gradually 
  to 
  an 
  attenuated 
  posterior 
  end); 
  10 
  were 
  developing 
  female 
  

   buds 
  as 
  indicated 
  by 
  the 
  developing 
  three 
  subequal 
  antennae 
  and 
  the 
  

   absence 
  of 
  forked 
  palps; 
  the 
  female 
  buds 
  consisted 
  of 
  40-65 
  setigers. 
  

   Color: 
  In 
  alcohol: 
  Two 
  dorsolateral, 
  longitudinal 
  dark 
  bands 
  just 
  

   dorsal 
  to 
  bases 
  of 
  dorsal 
  cirri 
  (almost 
  all 
  specimens 
  showed 
  at 
  least 
  

   faint 
  bands). 
  In 
  life: 
  Anterior 
  part 
  pale 
  yellowish 
  with 
  dark 
  dorso- 
  

   lateral 
  bands, 
  posterior 
  part 
  orange. 
  Tubes 
  : 
  Thin, 
  tough, 
  transparent, 
  

   on 
  hydroids 
  as 
  Lajoeina 
  maxima 
  Levinsen; 
  either 
  on 
  the 
  surface 
  or 
  

   surrounded 
  by 
  the 
  sessile 
  hydrothecae 
  of 
  the 
  hydroid 
  colony. 
  

  

  Female 
  stolon 
  (Sacconereis) 
  : 
  Length 
  5-15 
  mm., 
  width 
  without 
  

   setae 
  0.5-1 
  mm., 
  width 
  including 
  swimming 
  setae 
  3.5-4 
  mm., 
  up 
  to 
  

   26-51 
  segm^ents. 
  Body 
  widest 
  in 
  median 
  region, 
  tapering 
  slightly 
  

   anteriorly 
  and 
  more 
  so 
  posteriorly, 
  forming 
  an 
  attenuated 
  tail 
  region; 
  

   divided 
  into 
  three 
  regions 
  composed 
  of 
  6 
  anterior 
  unmodified 
  setigers, 
  

   13-18 
  modified 
  setigers 
  with 
  long, 
  iridescent 
  swimming 
  setae, 
  and 
  

   3-27 
  posterior 
  unmodified 
  setigers. 
  Prostomium 
  short, 
  broad, 
  one 
  

   pair 
  eyes 
  dorsolateral, 
  one 
  pair 
  larger 
  ones 
  ventrolateral, 
  both 
  with 
  

   lenses; 
  antennae 
  long, 
  stout, 
  subequal 
  or 
  median 
  one 
  slightly 
  longer 
  

   than 
  lateral 
  pair. 
  Upper 
  two 
  pairs 
  tentacular 
  cirri 
  similar 
  to 
  dorsal 
  

   chri 
  of 
  following 
  segments, 
  with 
  a 
  third 
  pair 
  of 
  short, 
  ventral, 
  tentacu- 
  

   lar 
  cirri 
  (about 
  length 
  of 
  prostomium) 
  and 
  a 
  pair 
  of 
  small, 
  ventral, 
  

   achaetous 
  lobes. 
  Dorsal 
  cirri 
  about 
  as 
  long 
  as 
  body 
  width. 
  Pair 
  

   of 
  shallow 
  semicircular 
  epaulettes 
  on 
  tentacular 
  segment 
  only. 
  Pyri- 
  

   form-shaped 
  egg 
  sac 
  carried 
  on 
  ventral 
  surface 
  in 
  region 
  of 
  setigers 
  

   10-18, 
  the 
  egg 
  mass 
  flattened 
  or 
  slightly 
  concave 
  on 
  side 
  toward 
  body, 
  

   the 
  narrower 
  end 
  of 
  lobe 
  anterior, 
  the 
  eggs 
  orange-colored 
  (in 
  life). 
  

   Color: 
  In 
  alcohol: 
  Colorless, 
  transparent, 
  may 
  be 
  dusky 
  posteriorly 
  

   or 
  somewhat 
  dusky 
  throughout. 
  Two 
  female 
  stolons 
  with 
  eggs 
  in- 
  

   side 
  body 
  dredged 
  in 
  75 
  fms. 
  October 
  11, 
  1949; 
  females 
  with 
  egg 
  sacs 
  

   taken 
  from 
  vertical 
  plankton 
  hauls 
  in 
  13 
  fathoms 
  March 
  29, 
  April 
  

   15, 
  May 
  17, 
  1950; 
  female 
  with 
  egg 
  sac 
  containing 
  developing 
  embryos 
  

   dredged 
  in 
  5 
  fathoms 
  January 
  25, 
  1950. 
  

  

  Male 
  stolons 
  (Polybostrichus) 
  : 
  Length 
  7-9 
  mm., 
  width 
  without 
  

   setae 
  0.8-1 
  mm., 
  width 
  including 
  swimming 
  setae 
  2 
  mm., 
  43-66 
  seg- 
  

  

  