﻿NO. 
  1946. 
  PACIFIC 
  MEDUSAE 
  AND 
  SIPHONOPHORAE—BIGELOW. 
  109 
  

  

  the 
  combined 
  records 
  of 
  Kishinoiiye 
  (1902, 
  1910), 
  Maas 
  (1909), 
  Doflein 
  

   (1906) 
  , 
  and 
  the 
  Fisheries 
  steamer 
  Albatross, 
  have 
  revealed 
  the 
  following 
  

   tropical 
  species: 
  Cytaeis 
  vulgaris, 
  Clavula 
  papua, 
  Prohoscydactyla 
  

   omata, 
  PTiialidium 
  pacificum, 
  P. 
  discoida, 
  Aequorea 
  pensile, 
  Liriope 
  

   tetraphylla, 
  Geryonia 
  prohoscidalis, 
  Rhopalonema 
  velatum, 
  Aglaura 
  

   Tiemistoma, 
  Solmundella, 
  Cunina 
  peregrina, 
  CTianjhdea 
  rastonii, 
  

   Pelagia 
  panopyra, 
  Sanderia 
  malayensis, 
  Dactylometra 
  pacijica, 
  Thysano- 
  

   stoma 
  tliysanura 
  and 
  Mastigias 
  papua, 
  with 
  the 
  following 
  siphono- 
  

   phores, 
  Ahylopsis 
  tetragona, 
  DipJiyes 
  appendiculata, 
  Dipliyopsis 
  

   dispar, 
  Dipliyopsis 
  chamissoms, 
  Forslcalea, 
  Pliysalia, 
  Porpita, 
  and 
  

   Velella; 
  all 
  of 
  them 
  being 
  widely 
  distributed 
  in 
  the 
  tropical 
  parts 
  

   of 
  the 
  Indo-Pacific. 
  

  

  This 
  list 
  suggests 
  that 
  the 
  pelagic 
  coelenterate 
  fauna 
  of 
  the 
  south- 
  

   east 
  coast 
  of 
  Japan 
  in 
  summer 
  is 
  overwhelmingly 
  tropical 
  ; 
  but 
  such 
  a 
  

   conclusion 
  is 
  correct 
  only 
  for 
  its 
  holoplanktonic 
  constituent 
  — 
  that 
  is, 
  

   for 
  the 
  inhabitants 
  of 
  the 
  warm 
  waters 
  of 
  the 
  Kuro 
  Shiro, 
  and 
  for 
  

   certain 
  scyphomedusae. 
  With 
  the 
  leptoline 
  forms 
  quite 
  a 
  different 
  

   state 
  of 
  affairs 
  is 
  to 
  be 
  seen, 
  because 
  the 
  list 
  does 
  not 
  include 
  any 
  

   of 
  the 
  leptoline 
  hydromedusae 
  which 
  are 
  the 
  most 
  characteristic 
  

   members 
  of 
  the 
  medusa 
  fauna 
  of 
  the 
  Phihppines, 
  the 
  Malaysian 
  

   region, 
  or 
  of 
  the 
  Maldives 
  and 
  tropical 
  Pacific, 
  such 
  as 
  Bougainvillea 
  

   fulva, 
  Laodicefijiana, 
  Tiaropsis 
  rosea, 
  PMalucium 
  mbenglia, 
  Irenopsis 
  

   hexanemalis, 
  Eutima 
  levulca, 
  Octocanna 
  polynema, 
  Gonionemus 
  suvaen- 
  

   sis, 
  or 
  the 
  genera 
  EupTiysora, 
  PJiortis, 
  or 
  Olindias. 
  A 
  full 
  list 
  of 
  the 
  

   Phihppine, 
  Malaysian, 
  and 
  tropical 
  West 
  American 
  hydromedusae, 
  

   and 
  their 
  distribution, 
  will 
  be 
  found 
  in 
  my 
  report 
  on 
  the 
  Albatross 
  

   Philippine 
  medusae. 
  

  

  In 
  Japanese 
  waters 
  the 
  place 
  of 
  Olindias 
  is 
  taken 
  by 
  Olindioides, 
  

   of 
  the 
  tropical 
  Gonionemus 
  suvaensis, 
  by 
  G. 
  vertens, 
  var. 
  depressum, 
  

   which 
  is 
  a 
  close 
  aUy 
  of 
  the 
  Gonionemus 
  of 
  the 
  cold 
  waters 
  of 
  Puget 
  

   Sound, 
  and 
  of 
  New 
  England. 
  Other 
  Japanese 
  leptoline 
  forms 
  

   recorded 
  by 
  Kishinouye 
  (1910) 
  and 
  by 
  Maas 
  (1909), 
  such 
  as 
  Nemopsis 
  

   dofleini, 
  Willia 
  pacijica, 
  Spirocodon 
  saltatrix, 
  are 
  peculiar 
  to 
  Japan, 
  

   so 
  far 
  as 
  we 
  know 
  yet. 
  The 
  absence 
  of 
  the 
  typically 
  tropical 
  leptoline 
  

   species, 
  which 
  are 
  so 
  common 
  among 
  the 
  Philippines, 
  is 
  probably 
  

   not 
  an 
  accidental 
  failure 
  in 
  collection, 
  but 
  is 
  an 
  actual 
  condition, 
  

   due 
  to 
  the 
  low 
  temperature 
  of 
  the 
  waters 
  off 
  the 
  east 
  coast 
  of 
  Japan 
  

   in 
  winter, 
  which 
  they, 
  or 
  their 
  hydroids, 
  can 
  not 
  survive. 
  But 
  in 
  

   the 
  case 
  of 
  the 
  holoplanktonic 
  species, 
  this 
  bar 
  is 
  operative 
  only 
  

   in 
  winter, 
  for 
  they 
  are 
  brought 
  to 
  Japan 
  in 
  summer 
  by 
  the 
  Kuro 
  

   Shiro, 
  when 
  the 
  latter 
  ^reads 
  toward 
  the 
  north. 
  

  

  Unfortunately 
  we 
  have 
  almost 
  no 
  data 
  on 
  the 
  medusa 
  fauna 
  of 
  

   the 
  east 
  coast 
  of 
  Nipon, 
  north 
  of 
  Yokohama 
  Bay; 
  indeed 
  I 
  have 
  

   not 
  been 
  able 
  to 
  find 
  a 
  single 
  definite 
  record; 
  but 
  we 
  can 
  safely 
  

   assume 
  that 
  before 
  Tsugaru 
  Strait 
  is 
  reached 
  the 
  tropical 
  contingent 
  

  

  