﻿410 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  tol.44. 
  

  

  irregularly 
  with 
  numerous 
  slender, 
  shaip, 
  recurved 
  hooks, 
  dark 
  brown 
  

   at 
  the 
  tip. 
  The 
  chitinous 
  holdfasts 
  near 
  the 
  posterior 
  end 
  of 
  the 
  

   trunk 
  are 
  blunt, 
  U-shaped, 
  and 
  of 
  a 
  light 
  yellowish-brown 
  color. 
  

  

  Type.—Csit. 
  No. 
  16323, 
  U.S.N.M. 
  From 
  Station 
  No. 
  79, 
  north 
  of 
  

   Nashawena. 
  

  

  PHASCOLION 
  STROMBI 
  var. 
  HYALINA, 
  new 
  variety. 
  

  

  Two 
  specimens 
  of 
  this 
  remarkable 
  form, 
  which 
  should 
  possibly 
  rank 
  

   as 
  a 
  distinct 
  species, 
  were 
  dredged 
  from 
  238 
  fathoms 
  at 
  station 
  895, 
  

   near 
  the 
  fortieth 
  parallel, 
  south 
  of 
  Marthas 
  Vineyard, 
  (type 
  locahty). 
  

   Another 
  small 
  female 
  came 
  from 
  365 
  fathoms 
  in 
  the 
  same 
  region 
  (sta- 
  

   tion 
  894) 
  . 
  All 
  were 
  inhabitants 
  of 
  the 
  tubes 
  of 
  the 
  annelid, 
  Hyalincccia. 
  

  

  The 
  body 
  of 
  a 
  contracted 
  specimen 
  is 
  nearly 
  cylindrical, 
  with 
  some- 
  

   what 
  truncated 
  extremities. 
  The 
  larger 
  specimens, 
  with 
  the 
  intro- 
  

   vert 
  completely 
  retracted, 
  are 
  22-25 
  mm. 
  in 
  length 
  and 
  4-5 
  mm. 
  in 
  

   diameter; 
  the 
  smallest, 
  a 
  sexually 
  mature 
  female, 
  is 
  10 
  mm. 
  long, 
  

   2 
  mm. 
  in 
  diameter. 
  The 
  introvert 
  in 
  the 
  contracted 
  specimens 
  is 
  

   about 
  two-tliirds 
  the 
  length 
  of 
  the 
  trunk, 
  and 
  the 
  conclusion 
  may 
  

   be 
  safely 
  drawn 
  that 
  its 
  length 
  in 
  the 
  living 
  animal 
  does 
  not 
  exceed 
  

   that 
  of 
  the 
  trunk. 
  

  

  The 
  body 
  wall 
  is 
  thin, 
  translucent, 
  of 
  brownish-gray 
  color 
  with 
  

   a 
  pearly 
  luster. 
  The 
  skin 
  is 
  smooth, 
  the 
  papillae 
  at 
  the 
  posterior 
  

   extremity 
  of 
  the 
  trunk 
  being 
  minute 
  and 
  those 
  at 
  the 
  anterior 
  

   extremity 
  not 
  conspicuous. 
  No 
  papillae 
  are 
  found 
  in 
  the 
  region 
  of 
  the 
  

   holdfasts 
  or 
  in 
  the 
  adjacent 
  middle 
  third 
  of 
  the 
  trunk. 
  The 
  holdfasts 
  

   are 
  light 
  brown, 
  capped 
  with 
  a 
  sharp 
  point 
  extending 
  forward. 
  

  

  The 
  retractor 
  muscles 
  resemble 
  those 
  of 
  other 
  varieties 
  in 
  that 
  

   the 
  attachment 
  of 
  the 
  dorsal 
  muscle 
  is 
  single, 
  whereas 
  that 
  of 
  the 
  

   ventral 
  has 
  two 
  roots, 
  but 
  the 
  attachment 
  of 
  the 
  latter 
  is 
  at 
  the 
  

   extreme 
  posterior 
  end 
  of 
  the 
  body 
  opposite 
  that 
  of 
  the 
  former, 
  and 
  

   not 
  slightly 
  in 
  front 
  of 
  it 
  as 
  in 
  other 
  varieties. 
  The 
  single 
  (right) 
  

   nephridium 
  is 
  remarkably 
  short. 
  The 
  eggs 
  are 
  large, 
  oval, 
  and 
  

   opaque, 
  150// 
  by 
  170/(, 
  or 
  150/x 
  by 
  160// 
  in 
  diameter 
  (in 
  alcohol). 
  

   The 
  above 
  measurements 
  were 
  taken 
  from 
  eggs 
  from 
  the 
  coelom 
  of 
  

   the 
  small 
  female, 
  the 
  trunk 
  of 
  wliich 
  was 
  onl}^ 
  10 
  mm. 
  long, 
  and 
  hence 
  

   it 
  is 
  evident 
  they 
  are 
  large 
  as 
  compared 
  with 
  the 
  size 
  of 
  the 
  body. 
  

   Eggs 
  of 
  the 
  common 
  variety, 
  fusca, 
  from 
  Boon 
  Island, 
  for 
  example, 
  

   are 
  only 
  106/z 
  in 
  diameter, 
  though 
  eggs 
  tliroughout 
  the 
  species 
  vary 
  

   much 
  in 
  size 
  and 
  in 
  translucency. 
  

  

  Type.— 
  C&t. 
  No. 
  15119, 
  U.S.N.M. 
  

  

  PHASCOLION 
  STROMBI 
  var. 
  GRACILIS, 
  new 
  variety. 
  

  

  Station 
  921, 
  lat. 
  40° 
  07' 
  48" 
  N.; 
  long. 
  70° 
  43' 
  54" 
  W.; 
  67 
  fathoms, 
  

   green 
  mud. 
  

  

  Station 
  922, 
  lat. 
  40° 
  03' 
  48" 
  N.; 
  long. 
  70° 
  45' 
  54" 
  W.; 
  71 
  fathoms, 
  

   green 
  mud 
  and 
  sand. 
  

  

  Station 
  949, 
  lat. 
  40° 
  03' 
  N.; 
  long. 
  70° 
  31' 
  W.; 
  100 
  fathoms, 
  yellow 
  

   mud. 
  

  

  