﻿422 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  tol. 
  44. 
  

  

  Station 
  2528, 
  lat. 
  41° 
  47' 
  N.; 
  long. 
  65° 
  37' 
  30" 
  W., 
  east 
  of 
  Georges 
  

   Bank, 
  677 
  fathoms, 
  brown 
  sand; 
  temperature 
  at 
  bottom, 
  38.7° 
  F. 
  

  

  Station 
  2072, 
  lat. 
  41° 
  53 
  N.; 
  long. 
  65° 
  35' 
  W., 
  south 
  of 
  Cape 
  Sable, 
  

   east 
  of 
  Province 
  town, 
  Massachusetts; 
  858 
  fathoms, 
  gray 
  mud; 
  tem- 
  

   perature 
  at 
  bottom, 
  39° 
  F. 
  

  

  The 
  range 
  of 
  tliis 
  species 
  extends 
  from 
  the 
  latitude 
  of 
  Cape 
  Cod 
  

   (station 
  2072) 
  southward 
  as 
  far, 
  at 
  least, 
  as 
  that 
  of 
  Cape 
  May 
  (station 
  

   2231). 
  It 
  is 
  found 
  at 
  depths 
  varying 
  from 
  677 
  to 
  1,769 
  fathoms. 
  

   No 
  other 
  species 
  of 
  this 
  genus, 
  with 
  the 
  exception 
  of 
  Ph. 
  lovenii 
  

   Koren 
  and 
  Danielssen, 
  has 
  been 
  found 
  as 
  far 
  north, 
  the 
  most 
  of 
  the 
  

   species 
  being 
  inhabitants 
  of 
  tropical 
  or 
  subtropical 
  waters. 
  The 
  tem- 
  

   peratm-e 
  of 
  the 
  water 
  from 
  which 
  the 
  specimens 
  were 
  taken 
  in 
  sum- 
  

   mer 
  and 
  autumn 
  was 
  36°-39° 
  F. 
  

  

  This 
  species 
  differs 
  from 
  others 
  of 
  this 
  genus 
  in 
  that 
  the 
  longitudinal 
  

   muscle 
  layer 
  is 
  entirely 
  continuous, 
  the 
  almost 
  universal 
  condition 
  

   m 
  Phascolosoma. 
  The 
  eggs 
  are 
  spherical, 
  as 
  in 
  Phascolosoma, 
  and 
  

   there 
  are 
  no 
  eye-spots 
  visible 
  upon 
  the 
  surface 
  of 
  the 
  cerebral 
  ganglion; 
  

   whereas 
  in 
  most 
  species 
  of 
  Physcosoma 
  the 
  eggs 
  are 
  said 
  to 
  be 
  ellip- 
  

   tical 
  and 
  flattened, 
  and 
  eye-spots 
  are 
  present. 
  The 
  peculiar 
  arrange- 
  

   ment 
  of 
  the 
  tentacles, 
  however, 
  dorsal 
  to 
  the 
  mouth 
  in 
  a 
  crescent 
  

   opening 
  dorsad 
  (pi. 
  51, 
  fig. 
  15), 
  places 
  this 
  species 
  in 
  the 
  genus 
  Phys- 
  

   cosoma. 
  

  

  Distinctive 
  features. 
  — 
  Trunk 
  ovate 
  with 
  thick, 
  rough, 
  dark-brown 
  

   integument, 
  thickly 
  studded 
  at 
  the 
  posterior 
  end 
  with 
  broad, 
  yellow- 
  

   ish-brown 
  and 
  hence 
  conspicuous 
  papillss, 
  which 
  elsewhere 
  are 
  thinly 
  

   scattered 
  over 
  the 
  trunk 
  (pi. 
  61, 
  fig. 
  16; 
  pi. 
  62, 
  fig. 
  21). 
  

  

  Introvert 
  cylmdrical, 
  shorter 
  than 
  the 
  trunk, 
  which 
  it 
  resembles 
  

   in 
  the 
  color 
  and 
  texture 
  of 
  the 
  skin, 
  except 
  in 
  the 
  anterior 
  fourth, 
  

   which 
  is 
  sharply 
  contrasted 
  with 
  the 
  rest 
  by 
  having 
  a 
  light 
  orange 
  

   color 
  and 
  thin 
  walls, 
  forming 
  an 
  oval 
  "head 
  " 
  (pi. 
  62, 
  fig. 
  21). 
  The 
  

   main 
  part 
  of 
  the 
  introvert 
  is 
  covered 
  with 
  light 
  yellowish-brown 
  papil- 
  

   lae, 
  which 
  are 
  about 
  twice 
  as 
  large 
  at 
  the 
  proximal 
  as 
  at 
  the 
  distal 
  end 
  

   of 
  this 
  region. 
  Papillae 
  of 
  smaller 
  size 
  extend 
  over 
  the 
  base 
  of 
  the 
  

   orange-colored 
  "head," 
  around 
  which 
  about 
  35 
  rows 
  of 
  minute 
  hooks 
  

   (pi. 
  61, 
  fig. 
  16) 
  extend. 
  There 
  are 
  14 
  tentacles, 
  arranged 
  in 
  the 
  char- 
  

   acteristic 
  fashion 
  of 
  Physcosoma, 
  dorsal 
  to 
  the 
  mouth 
  m 
  a 
  crescentic 
  

   row 
  opening 
  dorsad 
  (pi. 
  61, 
  fig. 
  15). 
  A 
  collar 
  consisting 
  of 
  an 
  annu- 
  

   lar 
  fold 
  of 
  integument 
  surrounds 
  the 
  anterior 
  part 
  of 
  the 
  "head," 
  

   immediately 
  behind 
  the 
  mouth 
  and 
  tentacles. 
  

  

  There 
  are 
  four 
  short 
  retractor 
  muscles 
  of 
  which 
  the 
  ventral, 
  which 
  

   are 
  much 
  the 
  larger, 
  are 
  attached 
  near 
  the 
  posterior 
  end 
  of 
  the 
  

   trunk; 
  the 
  slender, 
  dorsal 
  pair 
  are 
  attached 
  sUghtly 
  in 
  front 
  of 
  the 
  

   others, 
  and 
  unite 
  together 
  posterior 
  to 
  their 
  union 
  with 
  the 
  ventral 
  

   pair. 
  There 
  are 
  no 
  eye-spots. 
  The 
  eggs 
  are 
  spherical, 
  small, 
  and 
  

   transparent, 
  covered 
  with 
  a 
  yolk 
  membrane 
  pierced 
  with 
  distinct 
  

   pore 
  canals. 
  

  

  