﻿NO. 
  1946, 
  PACIFIC 
  MEDUSAE 
  AND 
  SIPHONOPHORAE—BIGELOW. 
  

  

  15 
  

  

  The 
  proportions 
  of 
  the 
  better-preserved 
  examples 
  are 
  as 
  follows: 
  

  

  I 
  Approximate. 
  

  

  No 
  one 
  of 
  the 
  examples 
  is 
  perfect, 
  but 
  several 
  of 
  them 
  are 
  well 
  

   enough 
  preserved 
  in 
  parts 
  to 
  allow 
  a 
  general 
  account. 
  

  

  The 
  bell 
  is 
  about 
  as 
  high 
  as, 
  or 
  slightly 
  higher 
  than 
  broad, 
  dome- 
  

   shaped, 
  the 
  gelatinous 
  substance 
  very 
  thin, 
  and 
  the 
  bell 
  cavity 
  

   voluminous. 
  In 
  four 
  of 
  the 
  specimens, 
  including 
  the 
  largest, 
  the 
  

   entire 
  subumbrella 
  is 
  so 
  densely 
  pigmented, 
  except 
  close 
  to 
  its 
  aboral 
  

   margin, 
  that 
  the 
  manubrium 
  is 
  entirely 
  hidden. 
  In 
  the 
  others 
  (pi. 
  2, 
  

   fig. 
  1) 
  the 
  subumbrella 
  surface 
  is 
  partially 
  rubbed 
  away. 
  

  

  Manubrium 
  and 
  gonads. 
  — 
  The 
  manubrium, 
  in 
  all 
  the 
  examples, 
  

   hangs 
  to 
  about 
  the 
  midlevel 
  of 
  the 
  bell 
  cavity; 
  and 
  it 
  is 
  attached 
  to 
  

   the 
  subumbrella 
  along 
  the 
  perradii 
  for 
  about 
  four-fifths 
  of 
  its 
  length 
  

   (pi. 
  2, 
  fig. 
  2). 
  The 
  lip, 
  primarily 
  cruciform, 
  is 
  thrown 
  into 
  many 
  

   extremely 
  complex 
  folds. 
  The 
  gonads 
  consist 
  of 
  a 
  close 
  network 
  of 
  

   ridges 
  and 
  corresponding 
  depressions, 
  which 
  occupy 
  the 
  entire 
  inter- 
  

   radial 
  areas. 
  They 
  do 
  not 
  connect 
  with 
  one 
  another 
  in 
  the 
  perradii 
  

   below 
  the 
  attachment 
  between 
  manubrium 
  and 
  subumbrella, 
  as 
  they 
  

   do 
  m 
  P. 
  conica, 
  but 
  are 
  discontinuous 
  there 
  (pi. 
  2, 
  fig. 
  2). 
  The 
  ridges 
  

   of 
  the 
  network 
  are 
  of 
  different 
  sizes, 
  representing 
  different 
  periods 
  of 
  

   formation; 
  and 
  in 
  the 
  largest 
  example, 
  unfortunately 
  a 
  fragmentary 
  

   one, 
  they 
  are 
  exceedingly 
  complex. 
  Seen 
  from 
  within, 
  the 
  gastric 
  

   wall 
  is 
  studded 
  with 
  prominences, 
  corresponding 
  to 
  the 
  hollows 
  

   between 
  the 
  external 
  ridges. 
  In 
  other 
  words, 
  the 
  ridges 
  are 
  not 
  

   simple 
  thickenings, 
  but 
  are 
  lines 
  of 
  outgrowth 
  and 
  folding. 
  

  

  Canal 
  system. 
  — 
  The 
  radial 
  canals 
  are 
  proportionately 
  broad 
  and 
  

   flat; 
  their 
  margins 
  wavy, 
  or 
  jagged 
  (pi. 
  2, 
  fig. 
  5) 
  , 
  and 
  notched. 
  In 
  one 
  

   specimen, 
  the 
  irregularities 
  of 
  their 
  margins 
  approach 
  the 
  condition 
  

   in 
  Catahlema 
  vesicaria, 
  where 
  they 
  may 
  be 
  spoken 
  of 
  as 
  diverticula; 
  

   but 
  there 
  is 
  considerable 
  variation 
  in 
  this 
  respect. 
  The 
  margin 
  of 
  

   the 
  circular 
  canal 
  is 
  smooth 
  in 
  such 
  specimens 
  as 
  are 
  well 
  enough 
  

   preserved 
  to 
  show 
  it, 
  including 
  the 
  largest 
  one. 
  

  

  Tentacles. 
  — 
  As 
  shown 
  in 
  the 
  foregoing 
  table, 
  five 
  interradial 
  ten- 
  

   tacles 
  is 
  the 
  greatest 
  number 
  observed 
  in 
  any 
  quadrant. 
  If 
  this 
  

   number 
  occurred 
  in 
  all 
  four 
  quadrants 
  of 
  any 
  one 
  individual, 
  we 
  

   should 
  have 
  a 
  total 
  of 
  24. 
  But 
  the 
  condition 
  varies 
  from 
  quadrant 
  

   to 
  quadrant 
  in 
  every 
  example. 
  Smaller 
  specimens 
  have 
  fewer, 
  2-4, 
  

   and 
  tentacles 
  were 
  observed 
  in 
  various 
  stages 
  in 
  growth. 
  

  

  