﻿NO. 
  1959. 
  8TPVNCVLIDS 
  OF 
  EASTERX 
  XORTH 
  AMERICA— 
  GEROULD. 
  389 
  

  

  but 
  several 
  hauls 
  made 
  for 
  this 
  purpose 
  in 
  the 
  same 
  locality 
  with 
  the 
  

   larger 
  apparatus 
  of 
  the 
  Fish 
  HawJc 
  were 
  unsuccessful. 
  

  

  The 
  depth 
  at 
  which 
  it 
  has 
  been 
  taken 
  varied 
  from 
  3f 
  to 
  8 
  fathoms 
  

   about 
  Woods 
  Hole, 
  and 
  was 
  16 
  fathoms 
  off 
  Cape 
  Hatteras. 
  It 
  occurs 
  

   either 
  in 
  sand 
  or 
  mud, 
  or 
  a 
  combination 
  of 
  the 
  two. 
  

  

  The 
  largest 
  specimens 
  that 
  I 
  have 
  examined 
  have 
  a 
  total 
  length 
  of 
  

   25 
  mm., 
  of 
  which 
  the 
  trunk 
  is 
  15 
  mm., 
  the 
  introvert 
  about 
  10 
  mm. 
  

   (pi. 
  58, 
  fig. 
  5). 
  The 
  somewhat 
  thick, 
  cylindrical 
  trunk 
  (thickness 
  one- 
  

   tenth 
  to 
  one-fifth 
  of 
  the 
  length) 
  tapers 
  rapidly 
  to 
  a 
  blunt 
  end 
  

   behind. 
  The 
  slender 
  cylindrical 
  introvert 
  has 
  a 
  uniform 
  diameter 
  

   except 
  at 
  the 
  base, 
  where 
  it 
  expands 
  slightly 
  as 
  it 
  joins 
  the 
  trunk. 
  

   Its 
  diameter 
  is 
  less 
  than 
  half 
  that 
  of 
  the 
  trunk 
  (as, 
  for 
  instance. 
  1 
  mm. 
  

   to 
  2.5 
  mm. 
  in 
  a 
  specimen 
  with 
  a 
  total 
  length 
  of 
  25 
  mm.). 
  

  

  There 
  is 
  a 
  single 
  row 
  of 
  34 
  tentacles, 
  or 
  less. 
  A 
  young 
  individual, 
  

   7 
  or 
  8 
  mm. 
  in 
  length, 
  has 
  12. 
  There 
  are 
  no 
  hooks 
  on 
  the 
  introvert. 
  

  

  This 
  species 
  has 
  the 
  peculiar 
  possibility, 
  under 
  adverse 
  conditions, 
  

   of 
  withdrawing 
  the 
  introvert 
  from 
  the 
  thick 
  cuticula 
  which 
  covers 
  it. 
  

   The 
  cuticula 
  is 
  first 
  loosened, 
  and 
  then 
  sloughed 
  oft", 
  but 
  retained 
  as 
  

   a 
  tubular, 
  or 
  trumpet-shaped, 
  protuberance 
  from 
  the 
  anterior 
  end 
  of 
  

   the 
  body, 
  like 
  the 
  proboscis 
  of 
  an 
  echiurid 
  (pi. 
  59, 
  fig. 
  7). 
  This 
  mal- 
  

   formation 
  does 
  not 
  prevent 
  the 
  alternate 
  introversion 
  and 
  extension 
  

   of 
  the 
  anterior 
  end 
  of 
  the 
  animal, 
  though 
  the 
  anterior 
  extremity 
  of 
  

   the 
  introvert 
  with 
  the 
  tentacles 
  can 
  not 
  be 
  completely 
  expanded. 
  

   This 
  peculiar 
  result 
  of 
  unfavorable 
  circumstances 
  appeared 
  in 
  both 
  

   of 
  the 
  living 
  specimens 
  that 
  I 
  examined, 
  the 
  fu'st 
  being 
  in 
  that 
  con- 
  

   dition 
  when 
  taken 
  from 
  the 
  dredge, 
  the 
  second 
  assuming 
  it 
  after 
  an 
  

   attempt 
  had 
  been 
  made 
  to 
  stupefy 
  the 
  animal 
  with 
  Aveak 
  alcohol. 
  

  

  The 
  color 
  varies 
  from 
  dark-seal 
  brown, 
  or 
  dark-steel 
  gray 
  with 
  

   iridescent 
  tints 
  and 
  dark-browTi 
  papilliB, 
  to 
  light 
  brown, 
  or 
  more 
  

   exactly 
  caf6-au-lait. 
  The 
  color 
  probably 
  depends 
  upon 
  the 
  nature 
  

   of 
  the 
  bottom. 
  The 
  seal-brown 
  specimens 
  were 
  taken 
  from 
  a 
  sandy 
  

   or 
  pebbly 
  bottom; 
  the 
  iridescent 
  steel-gray 
  specimen 
  from 
  sandy 
  

   mud, 
  and 
  the 
  light-brown 
  specimen 
  from 
  mud. 
  Ripe 
  males, 
  if 
  not 
  

   too 
  deeply 
  pigmented, 
  are 
  easily 
  distinguished 
  from 
  the 
  females 
  by 
  

   the 
  white 
  color 
  of 
  the 
  sperm 
  shining 
  through 
  the 
  translucent 
  walls 
  of 
  

   the 
  body. 
  

  

  Both 
  trunk 
  and 
  introvert 
  are 
  covered 
  with 
  prominent 
  papillae 
  of 
  a 
  

   darker 
  hue 
  than 
  the 
  rest 
  of 
  the 
  skin 
  (pi. 
  58, 
  fig. 
  5). 
  They 
  are 
  largest 
  

   and 
  most 
  crowded 
  at 
  the 
  posterior 
  end 
  of 
  the 
  trunk 
  and 
  at 
  the 
  base 
  

   of 
  the 
  introvert, 
  smallest 
  and 
  least 
  abundant 
  in 
  a 
  broad 
  zone 
  in 
  the 
  

   middle 
  of 
  the 
  trunk, 
  and 
  gradually 
  increase 
  in 
  size 
  and 
  abundance 
  

   fi'om 
  this 
  zone 
  backward 
  to 
  the 
  posterior 
  extremity. 
  Likewise 
  on 
  

   the 
  introvert 
  the 
  papillae 
  decrease 
  gradually 
  in 
  size 
  and 
  abundance 
  

   from 
  the 
  base 
  to 
  the 
  region 
  immediately 
  behind 
  the 
  tentacles, 
  which 
  

   are 
  nearly 
  devoid 
  of 
  papillae. 
  The 
  largepapillae 
  on 
  the 
  base 
  of 
  theintro- 
  

  

  