﻿60 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  vol.44. 
  

  

  Station 
  4805, 
  200-0 
  fathoms; 
  2 
  specimens, 
  7 
  and 
  10 
  mm, 
  in 
  

   diameter. 
  

  

  Station 
  4806, 
  200-0 
  fathoms; 
  1 
  specimen, 
  6 
  mm. 
  in 
  diameter. 
  

  

  In 
  these 
  young 
  Aeginas 
  the 
  8 
  gastric 
  pouches 
  (all 
  have 
  4 
  anti- 
  

   meres) 
  arc 
  not 
  divided 
  secondarily, 
  and 
  in 
  our 
  present 
  comparative 
  

   ignorance 
  of 
  the 
  growth-stages 
  of 
  the 
  genus, 
  it 
  is 
  impossible 
  to 
  be 
  

   certain 
  whether 
  they 
  belong 
  to 
  rosea 
  or 
  to 
  citrea. 
  

  

  None 
  of 
  them 
  are 
  in 
  good 
  enough 
  condition 
  for 
  me 
  to 
  count 
  the 
  

   otocysts. 
  

  

  Genus 
  AEGINURA 
  Haeckel, 
  1879. 
  

  

  Aeginura 
  Maas 
  (19046; 
  1905).— 
  Bigelow 
  (1909a).— 
  Mayer 
  (1910). 
  

   Cunoctona 
  Haeckel 
  (1879). 
  — 
  Vanhopfen 
  (1908). 
  

  

  Aeginidao 
  with 
  8 
  tentacles 
  and 
  16 
  gastric 
  pockets: 
  with 
  secondary 
  

   tentacles 
  on 
  the 
  margin 
  of 
  the 
  lappets. 
  

  

  There 
  is 
  no 
  need 
  to 
  repeat 
  the 
  history 
  of 
  this 
  genus 
  here. 
  Maas's 
  

   (1904&) 
  choice 
  of 
  Aeginura 
  as 
  the 
  generic 
  name 
  for 
  the 
  deeply 
  pig- 
  

   mented 
  mesoplanktonic 
  Aeginids 
  with 
  8 
  tentacles, 
  which 
  have 
  been 
  

   brought 
  to 
  light 
  by 
  the 
  recent 
  deep-sea 
  explorations 
  of 
  the 
  Prince 
  

   of 
  Monaco, 
  the 
  Sihoga, 
  and 
  the 
  Albatross, 
  seems 
  to 
  be 
  justified 
  by 
  a 
  

   strong 
  probability 
  that 
  they 
  are 
  congeneric 
  with 
  Haeckel's 
  A. 
  

   myosura. 
  A 
  different 
  stand 
  is 
  taken 
  by 
  Vanhoffen 
  (1908), 
  who 
  

   refers 
  them 
  to 
  Haeckel's 
  Cunoctona, 
  on 
  the 
  ground 
  that 
  the 
  latter 
  

   has 
  no 
  peripheral 
  canal 
  system, 
  whereas 
  his 
  Aeginura 
  had. 
  It 
  is 
  true 
  

   that 
  Haeckel's 
  figures 
  of 
  the 
  latter 
  apparently 
  show 
  a 
  well 
  developed 
  

   system 
  of 
  canals, 
  though 
  Maas 
  (1905, 
  p. 
  79) 
  has 
  pointed 
  out 
  that 
  the 
  

   "canals" 
  in 
  Haeckel's 
  section 
  (1881, 
  pi. 
  13, 
  fig. 
  7) 
  are 
  in 
  reality 
  

   portions 
  of 
  the 
  gastric 
  pockets 
  themselves, 
  such 
  as 
  are 
  to 
  be 
  seen 
  in 
  

   a 
  corresponding 
  figure 
  of 
  one 
  of 
  the 
  Sihoga 
  specimens 
  (Maas, 
  1905, 
  

   pi. 
  14, 
  fig. 
  92). 
  

  

  Vanhoffen 
  (1908) 
  found 
  no 
  canals 
  in 
  the 
  sections 
  of 
  the 
  margin 
  

   which 
  he 
  studied, 
  and 
  though 
  Maas 
  (1905) 
  observed 
  and 
  figured 
  

   spaces 
  in 
  the 
  entodermic 
  lamella 
  in 
  exactly 
  the 
  region 
  where 
  canals 
  

   would 
  be 
  expected, 
  these 
  probably 
  did 
  not 
  indicate 
  the 
  existence 
  of 
  

   canals, 
  because 
  there 
  was 
  no 
  definite 
  endothelial 
  layer 
  surrounding 
  

   them. 
  On 
  the 
  other 
  hand, 
  Haeckel's 
  figure 
  of 
  Cunoctona 
  certainly 
  

   suggests 
  tlie 
  presence 
  of 
  canals, 
  though 
  whether 
  or 
  not 
  it 
  actually 
  

   had 
  tliem 
  is 
  not 
  certain. 
  Under 
  these 
  circumstances 
  it 
  seems 
  idle 
  

   to 
  try 
  to 
  derive 
  a 
  generic 
  character 
  from 
  the 
  presence 
  or 
  absence 
  of 
  

   canals 
  in 
  Haeckel's 
  specimens. 
  Another 
  objection 
  to 
  referring 
  the 
  

   Aeginuras 
  of 
  modern 
  authors 
  to 
  Aeginura 
  Haeckel 
  is 
  the 
  fact 
  that 
  Jie 
  

   saw 
  no 
  secondary 
  tentacles, 
  while 
  he 
  figures 
  very 
  large 
  otocyst-clubs. 
  

   But 
  his 
  figure 
  is 
  obviously 
  more 
  or 
  less 
  reconstructed, 
  and 
  the 
  

  

  