﻿A 
  NEW 
  SPECIES 
  OF 
  POLYCHAETOUS 
  ANNELID 
  FROM 
  

   URUGUAY, 
  APHRODITA 
  MAGNA 
  

  

  A. 
  L. 
  Tread 
  well, 
  

  

  Of 
  the 
  Department 
  of 
  Zoology, 
  Vassar 
  College, 
  Poughkeepsie, 
  New 
  York. 
  

  

  While 
  engaged 
  in 
  the 
  study 
  of 
  the 
  fur-seal 
  and 
  other 
  fisheries 
  of 
  

   Uruguay, 
  Dr. 
  Hugh 
  M. 
  Smith, 
  former 
  United 
  States 
  Commissioner 
  

   of 
  Fisheries, 
  secured 
  a 
  large 
  specimen 
  of 
  Aphrodita 
  at 
  Cape 
  Polonia, 
  

   on 
  December 
  6, 
  1922. 
  This 
  specimen, 
  sent 
  me 
  for 
  determination 
  by 
  

   the 
  authorities 
  of 
  the 
  United 
  States 
  National 
  Museum, 
  proves 
  to 
  

   be 
  a 
  hitherto 
  undescribed 
  species. 
  

  

  APHRODITA 
  MAGNA, 
  new 
  species 
  

  

  The 
  holotype 
  (Cat. 
  No. 
  19124, 
  United 
  States 
  National 
  Museum) 
  

   is 
  111 
  mm. 
  long 
  and 
  50 
  mm. 
  in 
  greatest 
  width 
  when 
  measured 
  to 
  

   the 
  tips 
  of 
  the 
  parapodia 
  and 
  has 
  approximately 
  40 
  somites. 
  Dor- 
  

   sally 
  it 
  is 
  characterized 
  by 
  the 
  unusual 
  development 
  of 
  the 
  large 
  

   dark-brown 
  and 
  more 
  or 
  less 
  iridescent 
  setae 
  which 
  form 
  a 
  dense 
  

   fringe 
  along 
  either 
  side 
  of 
  the 
  dorsum 
  and 
  extend 
  to 
  a 
  distance 
  of 
  

   fully 
  25 
  mm. 
  beyond 
  the 
  point 
  of 
  their 
  emergence 
  from 
  the 
  felt. 
  

   From 
  10 
  to 
  15 
  of 
  these 
  large 
  setae 
  occur 
  in 
  each 
  somite. 
  The 
  felty 
  

   covering 
  is 
  very 
  dense 
  and 
  tough, 
  covering 
  the 
  dorsal 
  surface 
  in 
  

   a 
  band 
  from 
  25 
  to 
  30 
  mm. 
  wide, 
  and 
  filling 
  all 
  of 
  the 
  spaces 
  between 
  

   the 
  large 
  setae. 
  The 
  ventral 
  surface 
  has 
  no 
  very 
  noticeable 
  median 
  

   furrow 
  and 
  has 
  a 
  granular 
  appearance 
  due 
  to 
  the 
  presence 
  of 
  an 
  

   immense 
  number 
  of 
  globular 
  or 
  oval 
  papillae 
  which 
  are 
  slightly 
  

   darker 
  in 
  color 
  than 
  the 
  general 
  surface 
  of 
  the 
  body. 
  

  

  The 
  prostomium 
  (fig. 
  1) 
  is 
  roughly 
  pear-shaped 
  with 
  the 
  broader 
  

   end 
  anterior 
  and 
  the 
  narrow 
  portion 
  continued 
  posteriorly 
  as 
  a 
  

   parallel-sided 
  area 
  which 
  merges 
  with 
  the 
  first 
  somite. 
  When 
  first 
  

   exposed 
  by 
  the 
  removal 
  of 
  the 
  dorsal 
  felt 
  a 
  single 
  pair 
  of 
  ej^es 
  could 
  

   be 
  seen 
  on 
  the 
  side 
  of 
  the 
  prostomium. 
  After 
  standing 
  for 
  some 
  

   time 
  in 
  alcohol 
  these 
  became 
  invisible. 
  The 
  cirrophore 
  of 
  the 
  median 
  

  

  No. 
  2584— 
  Proceedings 
  U. 
  S. 
  National 
  Museum, 
  Vol. 
  67.?Art. 
  12. 
  

  

  27302—2." 
  1 
  

  

  