﻿Mr. 
  J. 
  W. 
  Fewkes 
  on 
  a 
  new 
  Athorybia. 
  207 
  

  

  XXI. 
  — 
  On 
  a 
  new 
  Athorybia. 
  By 
  J. 
  Walter 
  Fewkes. 
  

  

  [Plate 
  VII.] 
  

  

  The 
  genus 
  Athorybia 
  is 
  remarkable 
  among 
  Physophores 
  in 
  

   that 
  the 
  stem 
  is 
  very 
  short, 
  the 
  nectocalyces 
  are 
  absent, 
  and 
  

   the 
  appendages 
  appear 
  to 
  arise 
  about 
  the 
  base 
  of 
  the 
  float. 
  

   Its 
  whole 
  anatomy 
  shows 
  embryonic 
  features, 
  since 
  the 
  young 
  

   of 
  several 
  other 
  genera 
  of 
  Siphonophores 
  pass 
  through 
  a 
  stage 
  

   in 
  which 
  they 
  have 
  what 
  may 
  be 
  called 
  an 
  Athorybia-st&ge. 
  

   Athorybia 
  is, 
  in 
  point 
  of 
  fact, 
  a 
  genus 
  which, 
  while 
  it 
  has 
  

   embryonic 
  likenesses, 
  has 
  become 
  sexually 
  mature, 
  ajthough 
  

   it 
  is 
  ordinarily 
  regarded 
  as 
  an 
  adult. 
  Whether 
  or 
  not 
  it 
  ever 
  

   passes 
  out 
  of 
  this 
  stage 
  into 
  some 
  other 
  form 
  no 
  one 
  has 
  yet 
  

   been 
  able 
  to 
  discover. 
  

  

  From 
  the 
  coast 
  of 
  Florida 
  we 
  have 
  a 
  genus 
  allied 
  to 
  An- 
  

   thoj)hysa, 
  to 
  which 
  I 
  have 
  given 
  the 
  name 
  of 
  Diplorybia, 
  on 
  

   account 
  of 
  the 
  existence 
  of 
  two 
  kinds 
  of 
  tentacular 
  knobs 
  *. 
  

  

  The 
  waters 
  of 
  California, 
  so 
  rich 
  in 
  genera 
  of 
  Medusae, 
  have 
  

   not 
  hitherto 
  yielded 
  a 
  single 
  species 
  of 
  Athorybia. 
  The 
  writer 
  

   is 
  able 
  to 
  add 
  to 
  the 
  list 
  of 
  Medusae 
  found 
  in 
  the 
  waters 
  of 
  

   California 
  a 
  new 
  Athorybia 
  for 
  which 
  he 
  suggests 
  the 
  name 
  

   A. 
  cali/ornica. 
  

  

  Athorybia 
  californica, 
  sp. 
  no 
  v. 
  

  

  Float. 
  — 
  The 
  float 
  is 
  large, 
  conspicuous, 
  and 
  carried 
  upright 
  

   as 
  the 
  animal 
  swims 
  in 
  the 
  water. 
  Colour 
  pink, 
  with 
  apical 
  

   zone 
  dark 
  crimson 
  to 
  brown. 
  

  

  Nectocalyces. 
  — 
  No 
  nectocalyces 
  or 
  nectostem 
  present. 
  

  

  Hydrophyllia. 
  — 
  The 
  hydrophyllia 
  arise 
  from 
  an 
  enlarge- 
  

   ment 
  at 
  the 
  base 
  of 
  the 
  float. 
  They 
  are 
  leaf-like, 
  trans- 
  

   parent, 
  gelatinous, 
  placed 
  in 
  a 
  ring 
  about 
  the 
  lower 
  region 
  of 
  

   the 
  float, 
  above 
  the 
  polypites, 
  tasters, 
  and 
  tentacles. 
  They 
  

   are 
  ordinarily 
  carried 
  extended 
  at 
  right 
  angles 
  to 
  the 
  axis 
  of 
  

   the 
  float 
  and 
  are 
  capable 
  of 
  a 
  free 
  flapping 
  movement, 
  by 
  

   which 
  the 
  animal 
  may 
  be 
  propelled 
  through 
  the 
  water. 
  

  

  Each 
  hydrophyllium 
  is 
  thin, 
  indented 
  on 
  either 
  side 
  at 
  a 
  

   point 
  situated 
  about 
  half 
  its 
  length 
  by 
  a 
  well-marked 
  indenta- 
  

   tion 
  or 
  notch. 
  The 
  distal 
  extremity 
  is 
  rounded 
  and 
  pointed, 
  

   the 
  proximal 
  being 
  united 
  to 
  the 
  body 
  by 
  a 
  short 
  and 
  incon- 
  

  

  * 
  I 
  formerly 
  called 
  tins 
  Floridan 
  Physophore, 
  discovered 
  at 
  Key 
  West, 
  

   Florida, 
  a 
  new 
  species 
  of 
  A 
  thorybia 
  (A. 
  formosa). 
  Hseckel 
  refers 
  it 
  to 
  

   Anthophysa 
  ; 
  but 
  it 
  seems 
  to 
  me 
  that 
  it 
  should 
  receive 
  a 
  new 
  generic 
  

   name, 
  and 
  I 
  have 
  elsewhere 
  suggested 
  the 
  name 
  Diplorybia. 
  

  

  15* 
  

  

  