﻿NO. 
  1946. 
  PACIFIC 
  MEDUSAE 
  AND 
  8IPH0N0PH0RAE—BI0EL0W. 
  21 
  

  

  This 
  stage 
  of 
  muUicirrata 
  is 
  readily 
  distinguished 
  from 
  vesicaria, 
  as 
  

   is 
  the 
  adult, 
  by 
  the 
  very 
  large 
  number 
  of 
  tentacles, 
  for 
  in 
  the 
  latter, 
  

   at 
  about 
  the 
  same 
  stage 
  of 
  sexual 
  development, 
  there 
  are 
  usually 
  

   only 
  16-28 
  tentacular 
  organs 
  of 
  all 
  sizes. 
  Furthermore, 
  the 
  gonads 
  

   are 
  much 
  farther 
  advanced 
  in 
  vesicaria 
  of 
  the 
  same 
  size. 
  

  

  Family 
  BYTHOTIARIDAE 
  Maas, 
  1905. 
  

  

  [For 
  discust^ion 
  of 
  this 
  family 
  see 
  Maas 
  (1905, 
  1910) 
  and 
  my 
  earlier 
  paper 
  (1909a).] 
  

   Genus 
  CALYCOPSIS 
  Fewkes, 
  1882. 
  

  

  The 
  credit 
  for 
  pointing 
  out 
  that 
  my 
  Sibogita 
  nauarchus 
  is 
  a 
  synonym 
  

   of 
  the 
  insufficiently 
  described 
  and 
  long-forgotten 
  Calycopsis 
  typa 
  

   Fewkes 
  is 
  due 
  to 
  Dr. 
  A. 
  G. 
  Mayer 
  (1910, 
  p. 
  491), 
  and 
  Vanhoffen 
  

   (1911, 
  p. 
  214) 
  has 
  likewise 
  adopted 
  this 
  identification. 
  To 
  clinch 
  

   the 
  matter 
  I 
  have 
  examined 
  the 
  type-specimen 
  of 
  Fewkes's 
  species, 
  

   now 
  in 
  the 
  United 
  States 
  National 
  Museum, 
  finding 
  that 
  it 
  agrees 
  

   \\4th 
  my 
  material 
  even 
  to 
  minor 
  details. 
  

  

  The 
  following 
  species 
  of 
  Calycopsis 
  have 
  been 
  described: 
  typa 
  

   Fewkes 
  { 
  = 
  nauarchus), 
  simulans 
  Bigelow, 
  chuni 
  Vanhoffen, 
  horch- 
  

   grevinJd 
  Browne, 
  and 
  higelowi 
  Vanhoffen, 
  all 
  closely 
  allied 
  to 
  each 
  

   other. 
  The 
  first 
  three 
  are 
  known 
  from 
  large 
  mature 
  individuals, 
  so 
  

   that 
  we 
  have 
  a 
  fairly 
  definite 
  idea 
  of 
  their 
  final 
  state 
  of 
  development, 
  

   but 
  the 
  last 
  two 
  have 
  been 
  described 
  from 
  small 
  examples, 
  not 
  neces- 
  

   sarily 
  immature, 
  however. 
  

  

  Vanhofl'en 
  (1911) 
  in 
  his 
  survey 
  of 
  the 
  genus 
  has 
  laid 
  especial 
  stress 
  

   on 
  the 
  regularity 
  of 
  the 
  sexual 
  folds 
  and 
  on 
  color 
  as 
  specific 
  features; 
  

   but 
  there 
  is 
  another 
  character 
  which 
  proves 
  of 
  greater 
  value, 
  the 
  

   number 
  of 
  tentacles 
  and 
  their 
  relation 
  to 
  the 
  canals. 
  Using 
  this 
  as 
  

   a 
  criterion, 
  we 
  find 
  that 
  in 
  typa 
  and 
  in 
  simulans 
  there 
  are 
  about 
  as 
  

   many 
  tentacles 
  as 
  canals, 
  or 
  to 
  be 
  more 
  precise, 
  tentacles 
  are 
  formed 
  

   first, 
  but 
  the 
  corresponding 
  canals 
  shortly 
  follow. 
  Thus 
  there 
  are 
  

   often 
  more 
  tentacles 
  than 
  canals, 
  but 
  apparently 
  every 
  tentacle 
  is 
  

   eventually 
  associated 
  with 
  a 
  canal. 
  In 
  cJiuni 
  there 
  are 
  about 
  

   twice 
  as 
  man}^ 
  canals 
  as 
  tentacles. 
  Three 
  specimens 
  have 
  been 
  

   described 
  as 
  simulans, 
  two 
  from 
  the 
  eastern 
  tropical 
  Pacific, 
  one 
  

   from 
  Bering 
  Sea, 
  and 
  the 
  latter, 
  having 
  30 
  tentacles 
  and 
  only 
  16 
  

   canals, 
  might 
  seem 
  to 
  be 
  an 
  exception 
  to 
  the 
  above 
  statement. 
  But, 
  

   as 
  I 
  shall 
  show, 
  I 
  made 
  an 
  error 
  in 
  identifying 
  this 
  individual 
  as 
  

   simulans; 
  in 
  reality 
  it 
  probably 
  belonged 
  to 
  a 
  new 
  species, 
  nema- 
  

   topTiora, 
  represented 
  in 
  the 
  collection 
  by 
  an 
  excellent 
  series. 
  

  

  Vanhoffen 
  has 
  united 
  typa 
  and 
  simulans; 
  and 
  unquestionably 
  they 
  

   are 
  more 
  closely 
  related 
  to 
  each 
  other 
  than 
  is 
  either 
  of 
  them 
  to 
  chuni. 
  

   But 
  apart 
  from 
  the 
  terminations 
  of 
  the 
  canals 
  — 
  that 
  is, 
  whether 
  

   or 
  not 
  they 
  are 
  permanently 
  blind 
  in 
  typa 
  instead 
  of 
  finally 
  

   joining 
  the 
  base 
  of 
  the 
  manubrium 
  — 
  there 
  is 
  one 
  feature, 
  minor 
  it 
  is 
  

  

  