﻿NO. 
  1959. 
  SIPVNCULID8 
  OF 
  EASTERN 
  NORTB 
  AMERICA— 
  GEROVLD. 
  405 
  

  

  the 
  coasts 
  of 
  the 
  British 
  Isles, 
  France, 
  and 
  in 
  the 
  Mediterranean. 
  It 
  

   is 
  probably 
  the 
  most 
  common 
  sipmiculid 
  throughout 
  at 
  least 
  the 
  

   northern 
  part 
  of 
  its 
  range, 
  which 
  comprises 
  the 
  whole 
  of 
  the 
  Arctic 
  

   and 
  North 
  Atlantic 
  Oceans 
  and 
  the 
  Mediterranean 
  Sea. 
  

  

  The 
  size 
  of 
  Ph. 
  stromhi 
  varies 
  greatly 
  in 
  different 
  localities. 
  The 
  

   largest 
  specimens 
  that 
  I 
  have 
  examined 
  are 
  from 
  off 
  Portsmouth, 
  

   New 
  Hampshire 
  (station 
  76B, 
  51 
  fathoms), 
  the 
  contracted 
  trunk 
  of 
  

   which 
  measures 
  20 
  mm. 
  long, 
  7 
  mm. 
  thick, 
  but 
  the 
  largest 
  specimens 
  

   from 
  most 
  localities 
  have 
  a 
  trunk 
  of 
  about 
  15 
  mm.-17 
  mm. 
  in 
  length 
  

   and 
  4 
  mm.-5 
  mm. 
  in 
  thickness. 
  The 
  slender, 
  cylindrical 
  introvert 
  is 
  

   longer 
  than 
  the 
  trunk 
  (fig. 
  9) 
  . 
  It 
  is 
  impossible 
  to 
  determine 
  the 
  exact 
  

   dimensions 
  of 
  either 
  introvert 
  or 
  trunk 
  from 
  preserved 
  specimens 
  

   that 
  have 
  died 
  in 
  various 
  states 
  of 
  contraction, 
  and 
  I 
  have 
  not 
  

   had 
  the 
  opportunity 
  to 
  examine 
  the 
  live 
  

   animals, 
  but, 
  judging 
  from 
  the 
  numerous 
  

   preserved 
  specimens, 
  it 
  appears 
  that 
  the 
  

   length 
  of 
  the 
  introvert 
  varies 
  from 
  a 
  di- 
  

   mension 
  only 
  slightly 
  greater 
  than 
  that 
  of 
  

   the 
  trunk 
  to 
  about 
  twice 
  the 
  length 
  of 
  the 
  

   latter. 
  

  

  The 
  white 
  variety 
  from 
  the 
  shallow 
  waters 
  

   about 
  Woods 
  Hole 
  and 
  off 
  Block 
  Island 
  is 
  

   much 
  smaller. 
  

  

  The 
  shape 
  of 
  the 
  body 
  depends 
  upon 
  that 
  

   of 
  the 
  tubes 
  or 
  shells 
  which 
  the 
  animals 
  

   inhabit. 
  Those 
  which 
  live 
  in 
  gasteropod 
  

   shells 
  acquire 
  a 
  spiral 
  twist. 
  On 
  the 
  other 
  

   hand, 
  in 
  most 
  localities 
  they 
  live 
  in 
  tubes 
  of 
  

   then- 
  own 
  construction 
  (pi. 
  60, 
  fig. 
  10) 
  or 
  in 
  

   deserted 
  tubes 
  of 
  Pedinaria, 
  ProtuJa, 
  Hya- 
  

   linacia, 
  or 
  Dentalium, 
  and 
  accordingly 
  show 
  

   only 
  a 
  slight 
  tendency 
  toward 
  a 
  spiral 
  twist, 
  

   visible 
  merely 
  in 
  the 
  retracted 
  introvert. 
  

  

  The 
  mouth 
  of 
  the 
  cast 
  shell 
  or 
  the 
  tube 
  inhabited 
  by 
  individuals 
  of 
  

   this 
  species 
  from 
  off 
  the 
  American 
  coast 
  is 
  partially 
  closed 
  with 
  a 
  

   hollow 
  cone 
  composed 
  of 
  a 
  cement 
  made 
  of 
  mud 
  or 
  fine 
  sand, 
  often 
  

   inclosing 
  minute 
  pebbles, 
  and 
  held 
  together 
  by 
  a 
  secretion. 
  These 
  

   cones 
  sometimes 
  rise 
  as 
  much 
  as 
  5 
  mm. 
  above 
  the 
  mouth 
  of 
  the 
  shell 
  

   in 
  the 
  form 
  of 
  a 
  funnel. 
  I 
  have 
  found 
  a 
  small 
  amount 
  of 
  cemented 
  

   muddy 
  sand 
  in 
  shells 
  of 
  Dentalium 
  occupied 
  by 
  Ph. 
  stromhi 
  from 
  the 
  

   west 
  coast 
  of 
  Sweden, 
  sent 
  me 
  through 
  the 
  kindness 
  of 
  Prof. 
  Hj. 
  

   Theel, 
  though 
  I 
  judge 
  from 
  the 
  fact 
  that 
  no 
  mention 
  has 
  been 
  made 
  

   by 
  European 
  observers 
  of 
  cement 
  formation 
  in 
  this 
  species 
  that 
  it 
  

   never 
  is 
  a 
  conspicuous 
  phenomenon 
  in 
  shells 
  occupied 
  by 
  Ph. 
  stromhi 
  

   in 
  Europe, 
  these 
  shells 
  being 
  lined 
  with 
  loose 
  mud 
  or 
  sand. 
  It 
  was 
  

  

  -Phascolion 
  strombi. 
  

   X 
  4. 
  

  

  