﻿NO. 
  1946. 
  PACIFIC 
  MEDUSAE 
  AND 
  SIPHOXOPHORAE—BIGELOW. 
  77 
  

  

  These 
  anterior 
  nectophores 
  range 
  in 
  length 
  from 
  5 
  to 
  11 
  mm., 
  and 
  

   in 
  four 
  cases 
  there 
  is 
  a 
  young 
  bud 
  for 
  an 
  inferior 
  nectophore. 
  

  

  Chun's 
  account 
  and 
  figures 
  of 
  this 
  species 
  are 
  so 
  satisfactory 
  that 
  

   I 
  can 
  add 
  little 
  further 
  than 
  to 
  note 
  that 
  the 
  rounded 
  apex, 
  the 
  

   peculiar 
  hydroccium 
  opening 
  along 
  the 
  mid-ventral 
  line, 
  the 
  fact 
  

   that 
  the 
  dorsal 
  hydroecial 
  wall 
  below 
  the 
  level 
  of 
  the 
  bell 
  opening 
  is 
  

   undivided, 
  and 
  the 
  absence 
  of 
  basal 
  teeth 
  are 
  all 
  illustrated 
  by 
  our 
  

   specimens. 
  The 
  hydroecium, 
  especially, 
  is 
  so 
  characteristic 
  (Chun, 
  

   18976, 
  pi. 
  1, 
  fig. 
  1-3) 
  in 
  its 
  outlines 
  as 
  to 
  identify 
  the 
  specimens 
  at 
  a 
  

   glance. 
  The 
  somatocyst 
  is 
  rather 
  long, 
  reaching 
  slightly 
  above 
  the 
  

   mid-level 
  of 
  the 
  bell 
  cavity, 
  and 
  in 
  our 
  specimens 
  it 
  is 
  abruptly 
  

   truncate 
  basally, 
  connecting 
  with 
  the 
  hydroecium 
  at 
  its 
  dorsal 
  edge 
  

   (Chun, 
  18976, 
  pi. 
  1, 
  fig. 
  1); 
  but 
  it 
  may 
  be 
  rounded 
  basally 
  (Chun, 
  

   18976, 
  fig. 
  3), 
  the 
  difference 
  being 
  probably 
  due 
  to 
  contraction. 
  

  

  In 
  my 
  Key 
  to 
  the 
  Diphyopsinae 
  (19116, 
  p. 
  247) 
  this 
  species 
  was 
  

   omitted, 
  because 
  I 
  had 
  never 
  seen 
  it 
  and 
  because 
  Chun 
  mentioned 
  

   no 
  details 
  as 
  to 
  the 
  number 
  of 
  ridges. 
  In 
  the 
  present 
  series 
  the 
  apex 
  

   is 
  evenly 
  rounded, 
  as 
  Chun 
  shows 
  it 
  (18976, 
  pi. 
  1, 
  fig. 
  1), 
  and 
  there 
  are 
  

   no 
  distinct 
  ridges, 
  either 
  dorsal, 
  lateral, 
  or 
  ventral, 
  at 
  any 
  level; 
  

   indeed, 
  in 
  this 
  respect 
  D. 
  arctica 
  suggests 
  the 
  allied 
  genus 
  Galeolaria, 
  

   from 
  which, 
  however, 
  it 
  is 
  separated 
  by 
  its 
  deep 
  hydroecium, 
  and 
  by 
  

   the 
  fact 
  that 
  its 
  cormidia 
  are 
  set 
  free 
  as 
  eudoxids. 
  

  

  All 
  of 
  the 
  specimens 
  are 
  more 
  or 
  less 
  contracted 
  along 
  the 
  middle 
  

   lateral 
  line 
  on 
  either 
  side, 
  but 
  as 
  Chun's 
  figures 
  do 
  not 
  show 
  this, 
  it 
  

   may 
  be 
  the 
  result 
  of 
  contraction. 
  

  

  Inferior 
  nectojjhores. 
  — 
  As 
  noted 
  above, 
  four 
  specimens 
  have 
  the 
  

   bud 
  for 
  an 
  inferior 
  nectophore, 
  but 
  these 
  are 
  so 
  young 
  that 
  they 
  give 
  

   no 
  hint 
  of 
  their 
  future 
  form. 
  Their 
  presence, 
  however, 
  is 
  important, 
  

   because 
  they 
  corroborate 
  Chun's 
  (18976) 
  account, 
  and 
  are 
  sufficient 
  

   demonstrations 
  that 
  the 
  species 
  is 
  a 
  Diphyid, 
  not 
  a 
  Monophyid. 
  

   Only 
  the 
  basal 
  parts 
  of 
  the 
  stems 
  are 
  intact, 
  and 
  the 
  siphons, 
  gono- 
  

   phores, 
  and 
  bracts 
  which 
  are 
  intact 
  are 
  so 
  young 
  that 
  they 
  add 
  nothing 
  

   to 
  Chun's 
  account. 
  

  

  Genus 
  DIPHYOPSIS 
  Haeckel, 
  1888. 
  

  

  DIPHYOPSIS 
  DISPAR 
  (Chamisso 
  and 
  Eysenhardt) 
  Haeckel. 
  

  

  Diphyes 
  dispar 
  Chamisso 
  and 
  Eysenhardt, 
  1821, 
  p. 
  365, 
  pi. 
  33, 
  fig. 
  4. 
  

  

  (For 
  synonymy, 
  see 
  Bigelow, 
  19116, 
  p. 
  257.) 
  

  

  Station 
  4896, 
  surface; 
  4 
  anterior 
  nectophores, 
  6 
  mm. 
  long. 
  

   Station 
  4952, 
  surface; 
  6 
  anterior 
  nectophores, 
  8-11 
  mm. 
  long. 
  

   Station 
  4955, 
  surface; 
  1 
  anterior 
  nectophore. 
  

  

  Station 
  4978, 
  surface; 
  20 
  anterior 
  nectophores 
  and 
  about 
  20 
  pos- 
  

   terior 
  nectophores. 
  

  

  Station 
  5064, 
  300-0 
  fathoms; 
  4 
  anterior 
  nectophores. 
  

  

  