﻿NO. 
  1946. 
  PACIFIC 
  MEDUSAE 
  AND 
  8IPH0N0PH0RAE—BIGEL0W. 
  83 
  

  

  Class 
  SCYPHOMEDUSAE. 
  

  

  Order 
  CORONATA. 
  

   Family 
  PERIPHYLLIDAE 
  Haeckel, 
  1880. 
  

   Genus 
  PERIPHYLLA 
  Steenstrup, 
  1837. 
  

  

  For 
  accounts 
  of 
  the 
  anatomy 
  and 
  histology 
  of 
  this 
  genus, 
  see 
  

   Haeckel 
  (1881), 
  Maas 
  (1897, 
  1903, 
  19046), 
  and 
  Vanlioffen 
  (1902a). 
  

  

  The 
  present 
  collection 
  contains 
  a 
  large 
  and 
  excellently 
  preserved 
  

   series 
  of 
  typical 
  P. 
  liyacinthina, 
  ranging 
  from 
  very 
  young, 
  in 
  which 
  

   the 
  gonads 
  have 
  not 
  appeared, 
  to 
  an 
  example 
  70 
  mm. 
  in 
  diameter, 
  

   thus 
  affording 
  a 
  good 
  opportunity 
  to 
  trace 
  the 
  development 
  of 
  the 
  

   endodermic 
  pigment. 
  This 
  is 
  of 
  interest 
  because 
  this 
  character 
  is 
  

   used 
  by 
  Maas 
  (1904&) 
  and 
  by 
  Vanhoffen 
  (1902a) 
  to 
  separsitehyadnthina 
  

   from 
  dodecabostrycha, 
  the 
  former, 
  according 
  to 
  their 
  diagnoses, 
  being 
  

   so 
  densely 
  pigmented 
  over 
  the 
  entire 
  subumbrella 
  that 
  the 
  gonads 
  are 
  

   invisible 
  from 
  without, 
  the 
  latter 
  having 
  the 
  pigment 
  limited 
  to 
  the 
  

   gastric 
  cavity 
  and 
  upper 
  part 
  of 
  the 
  subumbrella, 
  allowing 
  the 
  gonads 
  

   to 
  show 
  through. 
  In 
  my 
  account 
  of 
  the 
  eastern 
  Pacific 
  medusae 
  

   (1909a) 
  I 
  gave 
  a 
  survey 
  of 
  the 
  published 
  evidence 
  on 
  this 
  question, 
  

   and 
  pointed 
  out 
  that 
  the 
  specimens 
  so 
  far 
  described 
  with 
  the 
  dodeca- 
  

   bostrycha 
  pigmentation 
  were 
  all 
  rather 
  small 
  ; 
  but 
  this 
  statement 
  needs 
  

   correction 
  because 
  Vanhoffen 
  has 
  called 
  my 
  attention 
  to 
  the 
  fact 
  

   that 
  I 
  overlooked 
  a 
  dodecabostrycha 
  56 
  mm. 
  broad 
  described 
  by 
  him, 
  

   and 
  which, 
  as 
  he 
  writes 
  me, 
  had 
  no 
  trace 
  of 
  pigment 
  in 
  the 
  ring-sinus. 
  

   It 
  appears 
  from 
  this 
  that 
  the 
  dodecabostrycha 
  condition 
  is 
  not 
  neces- 
  

   sarily 
  transitory, 
  though 
  the 
  present 
  series 
  shows 
  that 
  specimens 
  

   which 
  assume 
  the 
  hyacinthina 
  pigmentation 
  when 
  adult 
  pass 
  through 
  

   a 
  dodecabostrycha 
  stage. 
  And 
  it 
  also 
  shows 
  that 
  in 
  the 
  adult 
  there 
  

   is 
  a 
  good 
  deal 
  of 
  variation 
  in 
  the 
  density 
  of 
  the 
  pigmentation 
  of 
  the 
  

   peripheral 
  regions. 
  This 
  suggests, 
  of 
  course, 
  that 
  there 
  is 
  no 
  sharp 
  

   line 
  between 
  hyacinthina 
  and 
  dodecabostrycha; 
  that 
  if 
  the 
  two 
  are 
  

   distinguishable 
  at 
  all 
  they 
  are 
  at 
  most 
  varieties 
  of 
  one 
  species. 
  But 
  

   to 
  settle 
  the 
  relationship 
  of 
  the 
  two 
  will 
  require 
  more 
  data 
  than 
  is 
  

   available 
  at 
  present. 
  We 
  need, 
  especially, 
  series 
  of 
  growth 
  stages 
  of 
  

   the 
  dodecabostrycha 
  type, 
  and 
  large 
  series 
  of 
  the 
  adults 
  of 
  both, 
  to 
  

   show 
  whether 
  or 
  not 
  intermediates 
  occur. 
  Without 
  this 
  information 
  

   further 
  speculation 
  can 
  not 
  lead 
  to 
  any 
  definite 
  result. 
  

  

  The 
  status 
  of 
  P. 
  regina 
  is 
  also 
  unsettled. 
  Like 
  hyacinthina 
  it 
  is 
  

   so 
  densely 
  pigmented 
  that 
  the 
  gonads 
  are 
  concealed; 
  and 
  it 
  is 
  sepa- 
  

   rated 
  from 
  that 
  species 
  only 
  by 
  large 
  size 
  and 
  perhaps 
  by 
  a 
  brighter 
  

   red 
  color. 
  I 
  have 
  not 
  been 
  able 
  to 
  study 
  any 
  good 
  material 
  of 
  this 
  

   form, 
  so 
  do 
  not 
  feel 
  qualified 
  to 
  express 
  a 
  definite 
  opinion. 
  

  

  