﻿NO. 
  1946. 
  PACIFIC 
  MEDUSAE 
  AND 
  SIPHONOPHORAE—BIGELOW. 
  11 
  

  

  in 
  this 
  respect 
  is 
  anything 
  more 
  than 
  an 
  individual 
  variation, 
  or 
  per- 
  

   haps 
  partly 
  consequent 
  on 
  contraction. 
  

  

  The 
  Albatross 
  collection 
  contains 
  a 
  series 
  of 
  the 
  genus 
  which 
  

   differs 
  from 
  hlumenbachii 
  in 
  having 
  more 
  tentacles 
  (five 
  instead 
  of 
  

   three) 
  in 
  the 
  interradial 
  groups, 
  and 
  the 
  case 
  is 
  an 
  interesting 
  

   one, 
  because 
  perfectly 
  typical 
  hlumenbachii, 
  with 
  the 
  usual 
  num- 
  

   ber 
  of 
  tentacles, 
  is 
  common 
  in 
  Japan. 
  There 
  is, 
  then, 
  no 
  ques- 
  

   tion 
  of 
  a 
  Pacific 
  as 
  opposed 
  to 
  an 
  Atlantic 
  species. 
  The 
  difference 
  

   is 
  merely 
  the 
  point 
  to 
  which 
  development 
  proceeds; 
  the 
  north 
  At- 
  

   lantic 
  form 
  at 
  first 
  has 
  one 
  tentacle 
  in 
  each 
  interradial 
  group; 
  then 
  

   a 
  pair 
  flanking 
  it 
  appear, 
  and 
  then 
  in 
  its 
  Bering 
  Sea 
  relative 
  the 
  

   interradial 
  groups 
  simply 
  progress 
  one 
  step 
  further, 
  just 
  as 
  do 
  the 
  

   radial 
  groups. 
  And 
  as 
  it 
  appears 
  that 
  in 
  some 
  specimens 
  from 
  

   Bering 
  Sea 
  three 
  is 
  the 
  final 
  number, 
  just 
  as 
  it 
  is 
  in 
  the 
  Atlantic 
  

   species, 
  there 
  seems 
  to 
  be 
  no 
  justification 
  for 
  separating 
  the 
  series 
  

   specifically 
  from 
  blumenhachii, 
  though 
  it 
  may 
  finally 
  be 
  shown 
  that 
  

   they 
  represent 
  a 
  distinct 
  local 
  variety. 
  

  

  RATHKEA 
  BLUMENBACmi 
  (Rathke). 
  

  

  Oceania 
  hlumenbachii 
  Rathke, 
  1835, 
  p. 
  321. 
  

   (For 
  synonymy, 
  see 
  Mayer, 
  1910, 
  pp. 
  177, 
  179, 
  and 
  Hartlaub, 
  1911, 
  p. 
  229.) 
  

  

  Dutch 
  Harbor, 
  surface. 
  May 
  25; 
  about 
  40 
  specimens, 
  2-4 
  mm. 
  in 
  

   diameter; 
  in 
  excellent 
  condition. 
  

  

  I 
  have 
  been 
  able 
  to 
  compare 
  this 
  series 
  with 
  about 
  200 
  examples 
  

   from 
  Newfoundland 
  (1909c., 
  p. 
  306). 
  

  

  It 
  is 
  not 
  at 
  all 
  surprising 
  that 
  R. 
  blumenbachii 
  should 
  occur 
  in 
  Ber- 
  

   ing 
  Sea, 
  since 
  it 
  has 
  already 
  been 
  found 
  along 
  the 
  Arctic 
  coasts 
  of 
  

   Europe 
  as 
  far 
  east 
  as 
  Nova 
  Zembla, 
  and 
  likewise 
  in 
  Japari. 
  

  

  The 
  species 
  has 
  often 
  been 
  described, 
  and 
  excellent 
  diagnoses 
  are 
  

   to 
  be 
  found 
  in 
  Mayer's 
  (1910) 
  and 
  Hartlaub's 
  (1911) 
  papers, 
  whUe 
  

   the 
  latter 
  author 
  has 
  given 
  a 
  complete 
  list 
  of 
  the 
  localities 
  where 
  it 
  

   has 
  been 
  taken. 
  

  

  The 
  series 
  contains 
  both 
  budding 
  and 
  sexual 
  phases, 
  besides 
  a 
  con- 
  

   siderable 
  number 
  of 
  specimens 
  with 
  both 
  medusa 
  buds 
  and 
  gonads. 
  

   The 
  largest 
  are 
  about 
  4 
  by 
  4 
  mm. 
  — 
  that 
  is, 
  about 
  the 
  same 
  as 
  my 
  

   Newfoundland 
  series 
  — 
  and 
  the 
  photograph 
  of 
  the 
  oral 
  appendages 
  of 
  

   the 
  latter 
  (1909, 
  pi. 
  31, 
  fig. 
  5) 
  might 
  equally 
  well 
  have 
  been 
  taken 
  

   from 
  one 
  of 
  the 
  Bering 
  Sea 
  specimens. 
  The 
  largest 
  individuals 
  have 
  

   seven 
  or 
  eight 
  nematocyst 
  organs 
  in 
  each 
  cluster, 
  as 
  described 
  by 
  A. 
  

   Agassiz 
  (1865) 
  and 
  Browne 
  (1896). 
  According 
  to 
  the 
  degree 
  of 
  con- 
  

   traction, 
  the 
  nematocyst 
  knobs 
  may 
  be 
  sessile, 
  with 
  no 
  trace 
  of 
  stalk, 
  

   or 
  the 
  lip 
  may 
  be 
  extended 
  in 
  narrow 
  prolongations, 
  with 
  the 
  knobs 
  

   at 
  their 
  tips, 
  so 
  that 
  the 
  latter 
  are 
  apparently 
  stalked 
  ; 
  but 
  there 
  is 
  a 
  

   very 
  sharp 
  distinction 
  between 
  such 
  organs, 
  which 
  are 
  merely 
  pro- 
  

   jections 
  of 
  the 
  edge 
  of 
  the 
  lip, 
  and 
  the 
  labial 
  tentacles 
  of 
  Cytaeis, 
  

   Lizzia, 
  or 
  KiMikeria. 
  

  

  