﻿434 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  vol.44. 
  

  

  bands, 
  the 
  dorsal 
  to 
  the 
  eighth 
  and 
  nmth, 
  or 
  to 
  the 
  eighth 
  alone. 
  

   The 
  dorsal 
  retractor 
  of 
  each 
  side 
  is 
  united 
  to 
  the 
  ventral 
  in 
  front, 
  

   and 
  the 
  esophagus 
  is 
  attached 
  by 
  a 
  peritoneal 
  membrane 
  to 
  the 
  dor- 
  

   sal 
  edge 
  of 
  this 
  united 
  muscle 
  for 
  a 
  distance 
  equal 
  to 
  about 
  half 
  the 
  

   length 
  of 
  the 
  muscle. 
  The 
  two 
  lateral 
  muscles 
  thus 
  formed 
  by 
  the 
  

   union 
  of 
  a 
  dorsal 
  and 
  a 
  ventral 
  of 
  each 
  side 
  are 
  quite 
  separate 
  from 
  

   each 
  other, 
  though 
  they 
  tend 
  to 
  unite 
  in 
  front 
  where 
  each 
  is 
  attached 
  

   to 
  the 
  esophagus. 
  This 
  species 
  resembles 
  Sipunculus, 
  rather 
  than 
  

   Phascolosoma, 
  as 
  regards 
  the 
  position 
  of 
  the 
  esophageal 
  connectives 
  

   with 
  reference 
  to 
  the 
  retractor 
  muscles. 
  These 
  connectives, 
  as 
  they 
  

   run 
  dorsad 
  toward 
  the 
  supra-esophageal 
  ganglion, 
  are 
  surrounded 
  by 
  

   the 
  outer 
  ends 
  of 
  the 
  retractors 
  as 
  in 
  Sipunculus, 
  instead 
  of 
  surround- 
  

   ing 
  them 
  as 
  in 
  Phascolosoma. 
  The 
  proximal 
  half 
  of 
  each 
  of 
  the 
  two 
  

   long, 
  slender, 
  brown 
  nephridia 
  is 
  held 
  to 
  the 
  body 
  wall 
  by 
  a 
  fold 
  of 
  

   peritoneum. 
  Sclenka 
  (1883) 
  and 
  Keferstein 
  (1866), 
  however, 
  both 
  

   describe 
  the 
  nephridia 
  as 
  short, 
  attached, 
  as 
  Selenka 
  found, 
  only 
  by 
  

   the 
  anterior 
  haK. 
  The 
  nephridiopore 
  lies 
  between 
  longitudinal 
  mus- 
  

   cles 
  3 
  and 
  4. 
  The 
  dorsal 
  blood 
  vessel 
  (contractile 
  tube) 
  which 
  

   extends 
  the 
  length 
  of 
  the 
  esophagus, 
  is 
  covered 
  with 
  long, 
  slender 
  

   evaginations 
  which 
  give 
  it 
  a 
  tufted 
  appearance. 
  

  

  Tlie 
  long 
  intestinal 
  coil 
  consisting 
  of 
  12-50 
  turns 
  extends 
  back- 
  

   ward 
  to 
  the 
  posterior 
  end 
  of 
  the 
  coelom, 
  where 
  a 
  long 
  columellar 
  mus- 
  

   cle 
  holds 
  it 
  to 
  the 
  body 
  wall. 
  This 
  muscle 
  branches 
  radially 
  and 
  

   repeatedly 
  near 
  its 
  posterior 
  end, 
  and 
  forms 
  a 
  tree-shaped 
  attachment 
  

   to 
  the 
  body 
  wall. 
  The 
  intestinal 
  coil 
  is 
  held 
  in 
  position 
  along 
  its 
  entire 
  

   course, 
  from 
  the 
  base 
  of 
  the 
  ventral 
  retractors 
  backward, 
  by 
  numerous 
  

   transverse 
  sheets 
  of 
  peritoneum 
  arranged 
  at 
  regular 
  intervals 
  like 
  

   the 
  dissepiments 
  of 
  an 
  annelid. 
  These 
  sheets 
  are 
  attached 
  laterally, 
  

   but 
  not 
  dorsally, 
  to 
  the 
  body 
  wall 
  at 
  the 
  right 
  and 
  left 
  of 
  the 
  intes- 
  

   tine, 
  and 
  stretch 
  across 
  the 
  coelom 
  vertically. 
  They 
  are 
  not 
  attached, 
  

   as 
  far 
  as 
  I 
  can 
  discover, 
  to 
  the 
  intestinal 
  coil. 
  Four 
  muscle 
  strands 
  

   attach 
  the 
  rectum 
  to 
  the 
  body 
  wall, 
  namely, 
  (1) 
  the 
  anterior 
  end 
  of 
  

   the 
  columellar 
  muscle, 
  which 
  is 
  attached 
  to 
  the 
  body 
  wall 
  in 
  front 
  

   of 
  the 
  anus 
  and 
  extends 
  backward 
  through 
  the 
  entire 
  length 
  of 
  the 
  

   intestinal 
  coil, 
  (2) 
  two 
  pairs 
  of 
  branches 
  of 
  the 
  columellar 
  muscle, 
  one 
  

   pair 
  of 
  which 
  is 
  attached 
  to 
  the 
  body 
  wall 
  in 
  front 
  of 
  the 
  right-dorsal 
  

   retractors, 
  the 
  other 
  immediately 
  behind 
  or 
  between 
  the 
  attach- 
  

   ments 
  of 
  the 
  ventral 
  pair 
  to 
  the 
  body 
  wall. 
  The 
  anal 
  end 
  of 
  the 
  rec- 
  

   tum, 
  also, 
  in 
  the 
  variety 
  vitrea, 
  is 
  held 
  closely 
  to 
  the 
  body 
  wall 
  by 
  

   numerous 
  folds 
  of 
  peritoneum 
  and 
  fine 
  fibers 
  extending 
  over 
  10 
  or 
  12 
  

   longitudinal 
  muscle 
  bands. 
  A 
  prominent 
  caecum 
  is 
  situated 
  on 
  the 
  

   left 
  side 
  of 
  the 
  posterior 
  end 
  (beginning) 
  of 
  the 
  rectum. 
  

  

  The 
  body 
  wall 
  in 
  the 
  small 
  specimens 
  from 
  Key 
  West 
  is 
  more 
  trans- 
  

   lucent 
  than 
  in 
  the 
  larger 
  individuals 
  from 
  Oyster 
  Bay, 
  Florida, 
  so 
  

   that 
  I 
  have 
  identified 
  the 
  former 
  as 
  of 
  the 
  variety 
  vitrea 
  Sclenka 
  

  

  