﻿No. 
  1959 
  SIPUNCULIDS 
  OF 
  EASTERN 
  NORTH 
  AMERICA— 
  GEROULD. 
  419 
  

  

  Genus 
  PHYSCOSOMA 
  Selenka, 
  1897. 
  

  

  Phymosomum 
  Quatrefages, 
  1865. 
  

  

  Phymosoma 
  Selenka, 
  Bulow, 
  and 
  De 
  Man, 
  1883. 
  

  

  Longitudinal 
  muscle 
  layer 
  of 
  the 
  body 
  wall 
  in 
  most 
  species 
  discon- 
  

   tinuous 
  (continuous 
  in 
  Ph. 
  capitatum, 
  new 
  species). 
  Tentacles 
  in 
  a 
  

   single 
  row, 
  not 
  encircling 
  the 
  mouth, 
  but 
  situated 
  dorsal 
  to 
  it 
  along 
  a 
  

   crescent 
  opening 
  dorsad. 
  Body 
  covered 
  with 
  papillae. 
  Hooks, 
  

   arranged 
  in 
  rings, 
  usually 
  present 
  (not 
  in 
  PJi. 
  antillarum 
  Grube 
  and 
  

   Orsted). 
  Usually 
  four 
  retractors, 
  the 
  dorsal 
  and 
  ventral 
  of 
  each 
  

   side 
  tending 
  to 
  fuse. 
  Contractile 
  tube 
  in 
  most 
  species 
  without 
  cseca 
  

   (not 
  in 
  Ph. 
  antillarum 
  Grube 
  and 
  Orsted). 
  Eye-spots 
  generally 
  

   occur 
  (not 
  in 
  Ph. 
  capitatum). 
  

  

  PHYSCOSOMA 
  VARIANS 
  (Keferstein). 
  

  

  Phascolosoma 
  varians 
  Keferstein, 
  1865. 
  

   Phascolosoma 
  perlucens 
  Baird, 
  1868. 
  

  

  This 
  species 
  (pi. 
  62, 
  fig. 
  18) 
  is 
  abundant 
  at 
  Key 
  West 
  and 
  at 
  the 
  Dry 
  

   Tortugas, 
  Florida, 
  and 
  is 
  also 
  found 
  at 
  other 
  points 
  off 
  the 
  southern 
  

   coast 
  of 
  that 
  State, 
  as 
  at 
  Cape 
  Florida 
  and 
  Key 
  Vaccas. 
  It 
  is 
  abun- 
  

   dant 
  among 
  the 
  West 
  Indies 
  (Keferstein, 
  1866; 
  Selenka, 
  1883), 
  at 
  the 
  

   Bahamas 
  (Shipley, 
  1890), 
  Bermudas 
  (specimens 
  collected 
  for 
  me 
  

   through 
  the 
  kindness 
  of 
  Prof. 
  E. 
  L. 
  Mark), 
  and 
  occurs 
  also 
  at 
  Ascen- 
  

   sion 
  Island 
  in 
  the 
  South 
  Atlantic 
  (W. 
  H. 
  Brown, 
  Eclipse 
  Expedition 
  

   to 
  West 
  Africa, 
  1889). 
  

  

  The 
  following 
  is 
  a 
  translation 
  of 
  Keferstein 
  's 
  description 
  as 
  given 
  

   by 
  Selenka 
  (1883): 
  

  

  Trunk 
  three 
  to 
  four 
  times 
  as 
  long 
  as 
  thick, 
  introvert 
  as 
  long 
  as 
  or 
  

   longer 
  than 
  the 
  trunk. 
  Skin 
  yellowish, 
  thin, 
  somewhat 
  iridescent, 
  

   with 
  many 
  scattered, 
  large, 
  dome-shaped, 
  rounded 
  papillae, 
  which 
  are 
  

   darkly 
  pigmented 
  on 
  the 
  dorsal 
  side 
  of 
  the 
  animal 
  (a 
  dark 
  ring 
  with 
  

   a 
  light 
  center) 
  and 
  are 
  often 
  grouped 
  together 
  there 
  into 
  spots, 
  giv- 
  

   ing 
  a 
  marbleized 
  appearance. 
  The 
  diameter 
  of 
  the 
  papiUae 
  is 
  0.20- 
  

   0.22 
  mm. 
  The 
  posterior 
  half 
  of 
  the 
  introvert 
  resembles 
  the 
  trunk 
  in 
  

   appearance, 
  and 
  the 
  anus 
  is 
  not 
  conspicuous; 
  the 
  anterior 
  half, 
  on 
  

   the 
  other 
  hand, 
  bears 
  only 
  small 
  papillae, 
  appears 
  accordingly 
  rather 
  

   smooth, 
  and 
  is 
  often 
  pigmented 
  with 
  brown, 
  usually 
  transverse, 
  bands. 
  

   It 
  carries 
  numerous 
  closely-set 
  rows 
  of 
  hooks 
  of 
  very 
  variable 
  number 
  

   (12-90), 
  which, 
  accordingly, 
  in 
  many 
  cases 
  cover 
  only 
  the 
  most 
  an- 
  

   terior 
  part, 
  but 
  often 
  the 
  whole 
  anterior 
  half, 
  of 
  the 
  introvert. 
  The 
  

   hooks 
  are 
  very 
  characteristic, 
  broadly 
  leaf-shapedj 
  with 
  the 
  upper 
  

   point 
  bent 
  to 
  a 
  right 
  angle, 
  and 
  with 
  large, 
  rounded, 
  accessory 
  pro- 
  

   jections 
  on 
  the 
  inner 
  edge. 
  Between 
  the 
  rows 
  of 
  hooks 
  are 
  hook- 
  

   papillae 
  rather 
  regularly 
  arranged. 
  On 
  the 
  anterior 
  part 
  of 
  the 
  intro- 
  

   vert, 
  inmiediately 
  behind 
  the 
  tentacles, 
  is 
  an 
  entirely 
  smooth 
  zone. 
  

  

  