﻿[21] 
  ANNELIDA 
  CHJETOPODA. 
  727 
  

  

  Family 
  OPHELIID^E. 
  

   OPHELINA 
  CErsted. 
  

  

  Ophelina 
  aulogastra 
  Grube. 
  

  

  Ammoirypane 
  aulogaster 
  Rathke. 
  Beitriige 
  zur 
  Fauna 
  Norwegens, 
  p. 
  188, 
  pi, 
  x, 
  tigs, 
  

  

  1-3. 
  1840. 
  

   Ophelina 
  acuminata 
  (ERSTED. 
  Aun. 
  Dan. 
  Consp., 
  p. 
  45. 
  1843. 
  

   Ammotrypane 
  aulogastra 
  MAlmgren. 
  Anmilata 
  Polych., 
  p. 
  73. 
  18G7. 
  

   Ophelina 
  aulogastra 
  Grube. 
  Anmilata 
  Sempriana, 
  p. 
  193. 
  1877. 
  

  

  The 
  descriptions 
  of 
  this 
  species 
  differ 
  from 
  each 
  other 
  in 
  some 
  points. 
  

   (Ersted 
  assigns 
  branchiae 
  to 
  all 
  the 
  segments 
  ; 
  Rathke 
  and 
  Grube 
  say 
  

   that 
  they 
  begin 
  on 
  the 
  4th 
  setigerous 
  segment; 
  on 
  our 
  specimens 
  they 
  

   appear 
  sometimes 
  on 
  the 
  4th, 
  but 
  usually 
  on 
  the 
  2d, 
  setigerous 
  segment. 
  

   Grube 
  gives 
  44 
  pairs 
  of 
  branchiae: 
  Rathke 
  says 
  43, 
  with 
  one 
  ante-anal 
  

   segment 
  without 
  branchiae; 
  ours 
  have 
  42 
  pairs, 
  with 
  3 
  ante-anal 
  setig- 
  

   erous 
  segments 
  without 
  branchiae. 
  Grube 
  finds 
  pairs 
  of 
  lateral 
  pa- 
  

   pillae, 
  or 
  cirri, 
  on 
  the 
  anal 
  segment 
  ; 
  Rathke 
  none 
  ; 
  ours 
  have, 
  in 
  adults, 
  

   8 
  pairs, 
  and 
  a 
  terminal 
  cirrus. 
  The 
  head 
  is 
  not 
  correctly 
  figured 
  by 
  

   Rathke 
  ; 
  near 
  the 
  apex 
  is 
  a 
  well-defined 
  constriction, 
  followed 
  by 
  a 
  fusi- 
  

   form, 
  sharp-pointed 
  article. 
  

  

  Common. 
  Low 
  water 
  to 
  10 
  fathoms; 
  sand, 
  gravel, 
  and 
  shells. 
  

  

  Family 
  SCALlBREGMIDJE. 
  

   SCALIBREGMA 
  Rathke. 
  

  

  SCALIBREGMA 
  MINUTUM, 
  H. 
  sp. 
  

  

  Differs 
  from 
  Scalibregma 
  inflatum 
  Rathke 
  in 
  that 
  the 
  branchiae 
  begin 
  

   on 
  the 
  second 
  setigerous 
  segment, 
  and 
  in 
  having 
  five 
  anal 
  cirri 
  — 
  two 
  

   dorsal, 
  two 
  ventral, 
  one 
  medio- 
  ventral. 
  It 
  is 
  also 
  much 
  smaller 
  than 
  

   Rathke's 
  species. 
  

  

  The 
  notes 
  made 
  on 
  the 
  living 
  specimens 
  were 
  not 
  full, 
  and 
  the 
  pres- 
  

   ent 
  condition 
  of 
  the 
  alcoholic 
  specimens 
  does 
  not 
  admit 
  of 
  accurate 
  de- 
  

   scription. 
  

  

  Length, 
  5-7 
  mm 
  . 
  

  

  Diameter, 
  1.5-2 
  mm 
  . 
  

  

  Common. 
  Sand 
  and 
  mud, 
  shallow 
  dredgings. 
  

  

  Family 
  THELETHUSIDiE. 
  

   ARENICOLA 
  Lamarclc. 
  

  

  Arenicola 
  marina 
  L. 
  

  

  ISIot 
  generally 
  distributed, 
  but 
  abundant 
  at 
  Welch 
  Pool, 
  in 
  the 
  sand, 
  

   at 
  low 
  water. 
  

  

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