﻿212 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  103 
  

  

  9. 
  Setae 
  of 
  anterior 
  segments 
  directed 
  anteriorly, 
  forming 
  a 
  cephalic 
  cage. 
  

   Body 
  covered 
  with 
  papillae 
  and 
  often 
  with 
  adherent 
  sand 
  grains; 
  may 
  be 
  

  

  encased 
  in 
  thick 
  mucoid 
  sheath 
  Flabelligeridae 
  (p. 
  288) 
  

  

  Anterior 
  end 
  without 
  cephalic 
  cage 
  but 
  with 
  long, 
  filamentous 
  outgrowths 
  

   (may 
  have 
  2 
  groups 
  of 
  paleal 
  setae 
  directed 
  forward; 
  fig. 
  36, 
  a, 
  e, 
  /). 
  Body 
  

   without 
  papillae 
  10 
  

  

  10. 
  Anterior 
  end 
  with 
  long, 
  filamentous 
  outgrowths 
  and 
  with 
  similar 
  outgrowths 
  

  

  continued 
  along 
  sides 
  of 
  body 
  on 
  few 
  to 
  many 
  segments 
  (fig., 
  33, 
  a). 
  Seg- 
  

   ments 
  similar, 
  body 
  not 
  divided 
  into 
  2 
  distinct 
  regions. 
  

  

  Cirratulidae 
  (p. 
  285) 
  

  

  Long, 
  filamentous 
  outgrowths 
  concentrated 
  on 
  anterior 
  region 
  only 
  (figs. 
  36, 
  

  

  37). 
  Body 
  with 
  2 
  distinct 
  regions 
  11 
  

  

  11. 
  With 
  numerous 
  filiform 
  oral 
  tentacles 
  retractile 
  in 
  mouth 
  (fig. 
  36, 
  e). 
  Ante- 
  

  

  rior 
  region 
  with 
  or 
  without 
  2 
  groups 
  of 
  paleal 
  setae 
  directed 
  forward 
  (fig. 
  

  

  36, 
  a, 
  b) 
  Ampharetidae 
  (p. 
  314) 
  

  

  With 
  numerous, 
  grooved, 
  oral 
  tentacles 
  not 
  retractile 
  in 
  mouth 
  (fig. 
  36, 
  /, 
  g, 
  

   i) 
  . 
  Anterior 
  region 
  without 
  paleal 
  setae 
  Terebellidae 
  (p. 
  318) 
  

  

  12. 
  Opercular 
  setae 
  forming 
  1-3 
  concentric 
  rows 
  (fig. 
  34, 
  n-q). 
  Tube 
  of 
  con- 
  

  

  creted 
  sand 
  or 
  fine 
  gravel, 
  attached 
  Sabellariidae 
  (p. 
  307) 
  

  

  Opercular 
  setae 
  forming 
  2 
  bundles 
  in 
  horizontal 
  rows, 
  directed 
  obliquely 
  

   anteriorly 
  (fig. 
  35, 
  c, 
  d). 
  Tube 
  free, 
  conical, 
  rigid, 
  open 
  at 
  both 
  ends, 
  

   formed 
  of 
  single 
  layer 
  of 
  sand 
  grains 
  Pectinariidae 
  (p. 
  310) 
  

  

  13. 
  Prostomium 
  with 
  2-5 
  conspicuous 
  antennae. 
  With 
  1-8 
  pairs 
  tentacular 
  cirri 
  

  

  (figs. 
  27-29) 
  14 
  

  

  Prostomium 
  without 
  conspicuous 
  antennae. 
  Without 
  tentacular 
  cirri. 
  With 
  

   pair 
  of 
  tentaculiform, 
  longitudinally-grooved 
  palps 
  (deciduous, 
  may 
  be 
  

   missing; 
  figs. 
  32, 
  i; 
  33, 
  d) 
  17 
  

  

  14. 
  Dorsal 
  cirri 
  flattened, 
  foliaceous, 
  sometimes 
  overlapping, 
  or 
  more 
  or 
  less 
  

  

  globular 
  (fig. 
  27). 
  Prostomium 
  with 
  2 
  eyes, 
  4-5 
  antennae, 
  without 
  

  

  palps 
  Phyllodocidae 
  (p. 
  231) 
  

  

  Dorsal 
  cirri 
  otherwise. 
  Prostomium 
  ^vith 
  4-6 
  eyes, 
  2-3 
  antennae, 
  2 
  palps 
  

   (may 
  be 
  reduced 
  and 
  fused 
  in 
  Syllidae) 
  15 
  

  

  15. 
  With 
  parapodial 
  ligules, 
  rounded, 
  conical 
  or 
  straplike 
  lobes 
  (fig. 
  30, 
  h, 
  c). 
  

  

  Dorsal 
  cirri 
  short, 
  cirriform 
  Nereidae 
  (p. 
  263) 
  

  

  Without 
  parapodial 
  ligules. 
  Dorsal 
  cirri 
  filiform, 
  may 
  be 
  more 
  or 
  less 
  articu- 
  

   lated 
  (or 
  small 
  and 
  subulate 
  in 
  some 
  Syllidae) 
  16 
  

  

  16. 
  Palps 
  biarticulate 
  (fig. 
  28, 
  a) 
  Hesionidae 
  (p. 
  239) 
  

  

  Palps 
  not 
  biarticulate 
  (maj^ 
  be 
  reduced 
  and 
  fused; 
  figs. 
  28, 
  c; 
  29, 
  a). 
  

  

  Syllidae 
  (p. 
  240) 
  

  

  17. 
  Parapodia 
  with 
  postsetal 
  lamellae 
  more 
  or 
  less 
  developed 
  (fig. 
  32, 
  g). 
  Branch- 
  

  

  iae 
  usuall.y 
  paired, 
  dorsal, 
  ligulate 
  or 
  cirriform 
  (rarely 
  pinnate, 
  rarely 
  

  

  lacking) 
  Spionidae 
  (p. 
  280) 
  

  

  Parapodia 
  with 
  lobes 
  scarcely 
  projecting, 
  without 
  postsetal 
  lamellae. 
  Branch- 
  

   iae 
  simple, 
  filamentous, 
  contractile, 
  inserted 
  above 
  notopodia 
  on 
  few 
  to 
  

   many 
  segments 
  (fig. 
  33, 
  d) 
  Cirratulidae 
  (p. 
  285) 
  

  

  18. 
  Prostomium 
  with 
  2 
  pairs 
  minute 
  antennae 
  (figs. 
  30, 
  j; 
  31, 
  o) 
  19 
  

  

  Prostomium 
  without 
  antennae 
  22 
  

  

  19. 
  Prostomium 
  subquadrate, 
  with 
  small 
  antennae 
  on 
  anterior 
  part 
  (fig. 
  30, 
  j). 
  

  

  With 
  anterior 
  and 
  posterior 
  parapodial 
  lamellae 
  more 
  or 
  less 
  developed 
  

  

  (fig. 
  30, 
  k-n) 
  Nephtyidae 
  (p. 
  266) 
  

  

  Prostomium 
  conical, 
  pointed, 
  annulated, 
  with 
  tiny 
  terminal 
  antennae 
  (fig. 
  

   31, 
  o, 
  e). 
  Without 
  parapodial 
  lamellae 
  20 
  

  

  