﻿NO. 
  1946. 
  PACIFIC 
  MEDUSAE 
  AND 
  8IPH0N0PH0RAE—BIGEL0W. 
  95 
  

  

  the 
  marginal 
  lappets, 
  tentacles 
  and 
  rhopalia, 
  and 
  the 
  gonads, 
  so 
  

   clearly 
  that 
  there 
  is 
  no 
  doubt 
  of 
  their 
  identity 
  with 
  P. 
  polylohata. 
  

   Kishinouye 
  (1910) 
  has 
  given 
  a 
  good 
  account 
  of 
  the 
  species 
  (summa- 
  

   rized 
  by 
  Mayer, 
  1910). 
  

  

  In 
  our 
  smaller 
  specimen 
  the 
  canal 
  system 
  is 
  in 
  about 
  the 
  same 
  

   stage 
  as 
  in 
  Kishinouye's 
  figure, 
  except 
  that 
  one 
  of 
  the 
  adradial 
  canals 
  

   anastomoses 
  near 
  its 
  distal 
  end 
  with 
  the 
  perradial 
  on 
  one 
  side, 
  the 
  

   other 
  adradials 
  being 
  unbranched. 
  But 
  in 
  the 
  large 
  one 
  the 
  branch- 
  

   ing 
  and 
  anastomosis 
  of 
  the 
  per- 
  and 
  interradials 
  is 
  considerably 
  

   more 
  complex 
  than 
  he 
  shows 
  it, 
  though 
  less 
  so 
  than 
  it 
  is 
  in 
  philippina 
  

   CNIayer, 
  1910). 
  No 
  two 
  octants, 
  however, 
  are 
  exactly 
  alike. 
  In 
  

   this 
  specimen 
  all 
  of 
  the 
  adradials 
  anastomose 
  more 
  or 
  less 
  with 
  

   the 
  neighboring 
  per- 
  and 
  interradials 
  near 
  their 
  outer 
  ends, 
  though 
  

   the 
  exact 
  conditions 
  vary 
  from 
  octant 
  to 
  octant, 
  just 
  as 
  in 
  Dis- 
  

   comedusa 
  lobata 
  Claus. 
  The 
  margin, 
  with 
  its 
  narrow 
  lanceolate 
  lap- 
  

   pets, 
  agrees 
  very 
  well 
  with 
  Kishinouye's 
  figure, 
  except 
  that 
  he 
  does 
  

   not 
  show 
  the 
  eight 
  otocysts, 
  though 
  their 
  positions 
  are 
  indicated. 
  

  

  Kishinouye's 
  specimens 
  were 
  taken 
  in 
  Toyama 
  Bay, 
  and 
  according 
  

   to 
  the 
  local 
  fishermen 
  it 
  is 
  never 
  found 
  on 
  the 
  surface. 
  

  

  Genus 
  PHACELLOPHORA 
  Brandt, 
  1838. 
  

  

  An 
  excellent 
  account 
  of 
  the 
  general 
  structure 
  of 
  this 
  genus 
  has 
  

   been 
  given 
  by 
  Mayer 
  (1910), 
  but 
  it 
  is 
  so 
  far 
  loiown 
  from 
  so 
  few 
  

   specimens 
  that 
  it 
  is 
  difficult 
  to 
  decide 
  how 
  much 
  importance 
  should 
  

   be 
  attached 
  to 
  the 
  supposed 
  distinctions 
  between 
  its 
  four 
  members, 
  

   camtschatica 
  Brandt, 
  ambigua 
  Brandt, 
  ornata 
  Verrill, 
  and 
  sicula 
  

   Haeckel. 
  The 
  only 
  tangible 
  differences 
  between 
  them 
  are 
  afforded 
  by 
  

   the 
  degree 
  of 
  scalloping 
  or 
  subdivision 
  of 
  the 
  marginal 
  lappets, 
  for 
  

   although 
  a 
  considerable 
  range 
  has 
  been 
  recorded 
  for 
  the 
  number 
  of 
  

   tentacles 
  and 
  canals, 
  this 
  is 
  subject 
  to 
  individual 
  variation, 
  as 
  well 
  

   as 
  to 
  progressive 
  changes 
  with 
  growth. 
  

  

  In 
  P. 
  camtschatica, 
  which 
  is 
  necessarily 
  the 
  type 
  species 
  of 
  the 
  

   genus, 
  each 
  of 
  the 
  tentacular 
  lappets 
  is 
  cleft 
  into 
  seven, 
  and 
  the 
  

   sense 
  organ 
  is 
  apparently 
  covered 
  by 
  a 
  large 
  projecting 
  scale, 
  flanked 
  

   on 
  either 
  hand 
  b}'^ 
  a 
  narrow 
  lappet, 
  the 
  three 
  together 
  making 
  a 
  tri- 
  

   dentate 
  organ. 
  In 
  ambigua 
  each 
  tentacular 
  lappet 
  is 
  divided 
  into 
  

   two, 
  while 
  each 
  sense 
  organ 
  lies 
  at 
  the 
  bottom 
  of 
  a 
  deep 
  cleft 
  flanked 
  

   on 
  either 
  hand 
  by 
  a 
  rounded 
  rhopalar 
  lappet. 
  In 
  the 
  Mediterra- 
  

   nean 
  P. 
  sicula 
  the 
  rhopalar 
  lappets 
  are 
  rounded 
  and 
  separated 
  by 
  

   notches 
  from 
  the 
  tentacular 
  lappets, 
  which 
  are 
  entire 
  (Mayer, 
  1910, 
  

   p. 
  614, 
  fig. 
  392), 
  Just 
  what 
  the 
  condition 
  is 
  in 
  the 
  specimens 
  of 
  P. 
  

   ornata 
  collected 
  at 
  Eastport 
  by 
  Verrill 
  (1869) 
  and 
  afterwards 
  by 
  

   Fewkes 
  (1888) 
  is 
  not 
  clear, 
  for 
  while 
  Mayer 
  (1910) 
  represents 
  each 
  of 
  

   the 
  tentacular 
  lobes 
  of 
  one 
  of 
  the 
  former 
  as 
  subdivided 
  by 
  deep 
  

  

  