﻿432 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  vol.44. 
  

  

  A 
  loose 
  racemose 
  gland 
  (?) 
  lies 
  upon 
  each 
  of 
  the 
  rectal 
  muscles. 
  A 
  

   smooth-walled 
  sac-shaped 
  diverticulum 
  of 
  the 
  rectum 
  is 
  situated 
  near 
  

   its 
  junction 
  with 
  the 
  intestinal 
  coil. 
  A 
  slender 
  columellar 
  or 
  "spin- 
  

   dle 
  " 
  muscle 
  is 
  present. 
  

  

  Genus 
  SIPHONOSOMA 
  Spengel, 
  new 
  genus. 
  

  

  Through 
  the 
  kindness 
  of 
  Professor 
  Spengel 
  I 
  am 
  able 
  to 
  make 
  use 
  

   of 
  this 
  hitherto 
  unpublished^ 
  generic 
  term, 
  which 
  will 
  include 
  not 
  only 
  

   the 
  American 
  species 
  cumanensc, 
  but 
  also 
  those 
  formerly 
  called 
  Sipun- 
  

   culus 
  vastus, 
  arcassonensis, 
  hoholensis, 
  and 
  others.^ 
  Professor 
  Spengel 
  

   writes 
  that 
  SipJionosoma 
  is 
  characterized 
  by 
  its 
  integumental 
  canals, 
  

   which 
  are 
  not 
  longitudinal 
  as 
  in 
  S. 
  nndus, 
  but 
  isolated 
  blind 
  sacs 
  of 
  

   peculiar 
  form, 
  and 
  which 
  in 
  their 
  construction 
  and 
  arrangement 
  pre- 
  

   sent 
  highly 
  characteristic 
  differences; 
  also 
  by 
  the 
  course 
  of 
  the 
  ventral 
  

   nerve 
  cord, 
  which 
  is 
  closely 
  applied 
  to 
  the 
  skin 
  throughout 
  the 
  whole 
  

   introvert, 
  and 
  in 
  its 
  most 
  anterior 
  part 
  is 
  attached 
  to 
  it 
  by 
  a 
  short 
  

   median 
  mesentery. 
  In 
  the 
  extreme 
  anterior 
  end 
  of 
  this 
  mesentery 
  

   lies 
  a 
  fine 
  canal 
  opening 
  at 
  the 
  base 
  of 
  the 
  tentacles 
  that 
  runs 
  to 
  the 
  

   anterior 
  end 
  of 
  the 
  nerve 
  cord, 
  within 
  the 
  substance 
  of 
  which 
  it 
  enters 
  

   a 
  vesicle 
  that 
  appears 
  to 
  contain 
  a 
  concretion. 
  This 
  organ 
  evidently 
  

   represents 
  a 
  statocyst 
  provided 
  with 
  a 
  long 
  canal. 
  It 
  occurs 
  also 
  in 
  

   Physcosoma, 
  but 
  not 
  in 
  PTmscolosoma, 
  so 
  far 
  as 
  investigated. 
  The 
  

   ciliated 
  nuchal 
  organ 
  is 
  well 
  developed, 
  but 
  the 
  cerebral 
  tube 
  is 
  rep- 
  

   resented 
  only 
  by 
  a 
  shallow 
  pit. 
  "Other 
  characters 
  are 
  the 
  existence 
  

   of 
  a 
  thick 
  glandular 
  epithelium 
  in 
  the 
  wall 
  of 
  the 
  rectum, 
  the 
  mode 
  of 
  

   attachment 
  of 
  the 
  alimentary 
  canal 
  not 
  by 
  numerous 
  threads, 
  but 
  by 
  

   a 
  few 
  constant 
  'fixing 
  muscles' 
  as 
  described, 
  for 
  instance, 
  by 
  Selenka 
  

   in 
  S. 
  cumanense, 
  the 
  semilunar 
  form 
  of 
  the 
  nephrostomes, 
  the 
  

   arrangement 
  of 
  the 
  numerous 
  tentacles, 
  the 
  absence 
  of 
  triangular 
  

   scale-like 
  papillee 
  in 
  the 
  anterior 
  part 
  of 
  the 
  introvert, 
  and 
  others." 
  

  

  Type 
  species. 
  — 
  SipJionosoma 
  ausfrale 
  (Keferstein) 
  . 
  

  

  SIPHONOSOMA 
  CUMANENSE 
  (Keferstein) 
  and 
  var. 
  VITREA 
  (Selenka 
  and 
  Bulow). 
  

  

  Phascolosoma 
  cumanense 
  Keferstein, 
  1866. 
  

  

  Sipunculus 
  cumanensis 
  Selenka, 
  De 
  Man, 
  and 
  Bulow, 
  1883. 
  

  

  In 
  the 
  U. 
  S. 
  National 
  Museum 
  there 
  are 
  eight 
  specimens 
  of 
  the 
  type 
  

   form 
  from 
  Oyster 
  Bay, 
  Florida, 
  taken 
  among 
  "coon 
  oysters," 
  and 
  

   three 
  of 
  the 
  variety 
  vitrea 
  from 
  Key 
  West, 
  from 
  sand 
  along 
  shore. 
  

  

  This 
  species 
  (pi. 
  60, 
  fig. 
  14), 
  originally 
  described 
  by 
  Keferstein 
  (1866) 
  

   as 
  Phascolosoma 
  cumanense, 
  in 
  some 
  respects 
  is 
  an 
  intermediate 
  

   type 
  between 
  that 
  genus 
  and 
  Sipunculus. 
  Its 
  slender, 
  separate 
  ten- 
  

   tacles 
  are 
  distinctly 
  like 
  those 
  of 
  Phascolosoma, 
  and 
  not 
  like 
  those 
  of 
  

  

  » 
  A 
  preliminary 
  account 
  of 
  this 
  new 
  genus 
  and 
  of 
  Its 
  relations 
  to 
  Sipunculm 
  by 
  Professor 
  Spengel 
  was 
  

   received 
  while 
  the 
  present 
  paper 
  was 
  in 
  press. 
  See 
  List 
  of 
  References: 
  Spengel 
  (1012). 
  

  

  s 
  Complete 
  list 
  of 
  the 
  species: 
  australe, 
  cumanensc, 
  lastum, 
  boholense, 
  edule 
  Sluitor 
  (not 
  Pallas), 
  arc(M 
  

   tonenae, 
  amamiense, 
  bonhourei, 
  rotumanum,funafutU 
  

  

  