﻿88 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  vou 
  44. 
  

  

  as 
  anywhere 
  else. 
  The 
  true 
  explanation 
  of 
  these 
  clear 
  spaces 
  is 
  

   afforded 
  by 
  the 
  fact 
  that 
  the 
  dense 
  entodermal 
  pigmentation 
  of 
  

   the 
  aboral 
  surfaces 
  of 
  the 
  canal 
  walls 
  is 
  lacking 
  in 
  the 
  clear 
  spaces. 
  

   When 
  the 
  pigmented 
  ectoderm 
  of 
  the 
  subumbrella 
  is 
  rubbed 
  off 
  the 
  

   spaces 
  are 
  noticeable; 
  and 
  this 
  has 
  happened 
  more 
  or 
  less 
  in 
  most 
  

   of 
  the 
  specimens, 
  even 
  when 
  they 
  are 
  otherwise 
  in 
  oxceUent 
  condition. 
  

   There 
  is 
  one 
  specimen 
  in 
  which 
  the 
  subumbrella 
  pigment 
  is 
  intact, 
  

   and 
  in 
  this 
  one 
  the 
  false 
  septa 
  are 
  only 
  very 
  faintly 
  visible. 
  

  

  The 
  general 
  structure 
  of 
  the 
  peripheral 
  canal 
  system 
  has 
  been 
  

   described 
  by 
  Vanhoffen 
  (1902a) 
  for 
  valdiviae, 
  hy 
  Mnhs 
  (19046) 
  for 
  

   hairdii 
  and 
  by 
  me 
  (1909a) 
  for 
  wyvillei. 
  

  

  Order 
  DISCOPHORA. 
  

  

  Suborder 
  SAEMAEOSTOMATA. 
  

  

  Family 
  PELAGIDAE 
  Gegenbaur. 
  1856. 
  

   Genus 
  PELAGIA 
  Peron 
  and 
  Lesueur. 
  

  

  The 
  revision 
  of 
  this 
  genus 
  would 
  be 
  of 
  great 
  value 
  to 
  the 
  zoogeog- 
  

   rapher 
  as 
  well 
  as 
  to 
  students 
  of 
  pelagic 
  coelenterates 
  ; 
  but 
  it 
  must 
  

   be 
  postponed 
  until 
  some 
  one 
  has 
  access 
  to 
  large 
  series 
  from 
  all 
  oceans. 
  

   For 
  the 
  present, 
  the 
  chief 
  duty 
  of 
  any 
  one 
  who 
  can 
  examine 
  a 
  small 
  

   series 
  of 
  Pelagias 
  is 
  to 
  give 
  the 
  details 
  of 
  the 
  two 
  characters 
  which, 
  

   according 
  to 
  Maas 
  (1903) 
  and 
  Mayer 
  (1910) 
  separate 
  the 
  ''species," 
  

   i. 
  e., 
  proportions 
  of 
  manubrium 
  and 
  mouth 
  arms, 
  and 
  form 
  of 
  the 
  

   exumbral 
  nettle 
  knobs. 
  

  

  The 
  specimens 
  in 
  the 
  collection 
  agree 
  very 
  well 
  with 
  the 
  eastern 
  

   Pacific 
  examples, 
  with 
  the 
  Siboga 
  material 
  described 
  by 
  Maas 
  (1903), 
  

   with 
  the 
  Valdivia 
  collection 
  which 
  Vanhoffen 
  described 
  as 
  P. 
  pJiosphora, 
  

   and 
  with 
  specimens 
  from 
  the 
  Hawaiian 
  Islands, 
  the 
  Philippines, 
  and 
  

   from 
  Australia. 
  I 
  have 
  given 
  elsewhere 
  (1909a) 
  the 
  reasons 
  for 
  the 
  

   choice 
  of 
  the 
  name 
  panopyra 
  Peron 
  and 
  Lesueur 
  for 
  this 
  form. 
  

  

  PELAGIA 
  PANOPYRA 
  (P6ron 
  and 
  Lesueur). 
  

  

  Medusa 
  panopyra 
  P^ron 
  and 
  Lesueur, 
  1807, 
  pi. 
  31, 
  fig. 
  2. 
  

  

  (For 
  synonymy, 
  see 
  Bigelow, 
  1909a, 
  p. 
  43.) 
  

  

  Station 
  4910, 
  surface; 
  1 
  specimen. 
  

   Station 
  4920, 
  surface; 
  7 
  specimens. 
  

   Station 
  4921, 
  surface; 
  about 
  15 
  specimens. 
  

   Station 
  4926, 
  165 
  fathoms; 
  1 
  specimen. 
  

   Station 
  4932, 
  surface; 
  25 
  specimens. 
  

   Station 
  4950, 
  surface; 
  1 
  specimen. 
  

   Station 
  4952, 
  surface; 
  15 
  specimens. 
  

   Station 
  4954, 
  850-0 
  fathoms; 
  3 
  specimens. 
  

  

  