﻿18 
  

  

  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  

  

  zontal 
  folds 
  in 
  the 
  upper 
  part 
  of 
  each 
  interradius, 
  but 
  instead 
  of 
  being 
  

   fairly 
  regular 
  and 
  even, 
  as 
  they 
  are 
  in 
  typical 
  vesicaria, 
  they 
  branch 
  

   and 
  even 
  anastomose, 
  so 
  that 
  a 
  very 
  loose 
  partial 
  network 
  results, 
  

   and 
  the 
  folds 
  are 
  augmented 
  in 
  the 
  lower 
  part 
  of 
  the 
  manubrium 
  by 
  

   numerous 
  knobs 
  and 
  irregular 
  swellings. 
  

  

  A 
  comparison 
  of 
  photographs 
  of 
  the 
  gonads 
  of 
  the 
  two 
  (cf. 
  pi. 
  1, 
  fig. 
  8 
  

   with 
  Bigelow 
  1909c, 
  pi. 
  30, 
  fig. 
  3), 
  will 
  show 
  the 
  difference 
  at 
  a 
  glance. 
  

   If 
  extremes 
  only 
  were 
  taken, 
  they 
  would 
  suggest 
  two 
  different 
  species, 
  

   but 
  occasional 
  Atlantic 
  specimens 
  approach 
  the 
  Pacific 
  type 
  so 
  

   closely 
  that 
  there 
  is 
  no 
  actual 
  discontinuity 
  between 
  the 
  two. 
  In 
  

   young 
  specimens 
  from 
  the 
  Pacific 
  the 
  folds 
  are 
  less 
  irregular 
  and 
  

   branch 
  little 
  if 
  at 
  all, 
  so 
  that 
  they 
  resemble 
  the 
  usual 
  Atlantic 
  form 
  

   more 
  closely, 
  but 
  the 
  knobs 
  are 
  already 
  present 
  in 
  examples 
  9 
  mm. 
  

   high. 
  This 
  type 
  of 
  gonad 
  is 
  present 
  in 
  all 
  the 
  specimens, 
  though 
  the 
  

   degree 
  of 
  development 
  of 
  the 
  knobs 
  varies. 
  

  

  The 
  tentacles 
  are 
  rather 
  less 
  numerous, 
  and 
  have 
  basal 
  bulbs 
  of 
  

   rather 
  a 
  different 
  outline 
  from 
  those 
  of 
  the 
  Atlantic 
  specimens 
  which 
  

   I 
  have 
  seen. 
  

  

  In 
  the 
  following 
  table 
  tentacle 
  number 
  is 
  given 
  of 
  a 
  series 
  including 
  

   the 
  largest 
  and 
  smallest 
  specimens: 
  

  

  Thus 
  the 
  number 
  increases 
  with 
  growth, 
  but 
  so 
  irregularly 
  that 
  

   it 
  is 
  seldom 
  that 
  two 
  quadrants 
  of 
  any 
  individual 
  have 
  the 
  same 
  

   number 
  of 
  tentacular 
  organs 
  at 
  exactly 
  the 
  same 
  stages 
  of 
  growth. 
  

  

  It 
  is 
  hard 
  to 
  classify 
  the 
  tentacles 
  by 
  size, 
  because 
  there 
  are 
  all 
  

   gradations 
  from 
  large 
  ones 
  to 
  mere 
  knobs, 
  and 
  the 
  latter 
  are 
  present 
  

   in 
  the 
  largest 
  as 
  well 
  as 
  in 
  the 
  smaller 
  specimens. 
  

  

  The 
  order 
  of 
  development 
  of 
  tentacles 
  is 
  successively 
  radial, 
  inter- 
  

   radial, 
  adradial, 
  and 
  subradial. 
  But 
  after 
  the 
  first 
  three 
  series 
  have 
  

   appeared 
  the 
  formation 
  of 
  additional 
  tentacles 
  is 
  exceedingly 
  irregular. 
  

  

  Atlantic 
  examples 
  of 
  vesicaria, 
  of 
  about 
  the 
  same 
  size 
  as 
  the 
  largest 
  

   Bering 
  Sea 
  specimens, 
  have 
  twice 
  as 
  many 
  tentacular 
  organs 
  of 
  all 
  

   sizes. 
  Thus, 
  in 
  a 
  specimen 
  19 
  mm. 
  high 
  by 
  17 
  mm. 
  in 
  diameter, 
  I 
  

   counted 
  22 
  large 
  and 
  20 
  small, 
  and 
  in 
  another 
  18 
  by 
  14.5 
  mm. 
  there 
  

   were 
  37 
  large 
  and 
  2 
  small. 
  Haeckel 
  (1879) 
  records 
  36-48 
  tentacles 
  

   as 
  the 
  final 
  number. 
  

  

  