﻿480 
  COLLECTIONS 
  FROM 
  MELANESIA. 
  

  

  106. 
  Geodia 
  globostellifera. 
  (Plate 
  XLIII. 
  fig. 
  b.) 
  

   Carter, 
  Ann. 
  >Sf 
  Mag. 
  N. 
  H. 
  1880, 
  vi. 
  p. 
  134, 
  pi. 
  vi. 
  fig. 
  38. 
  

  

  I 
  have 
  been 
  able 
  conclusively 
  to 
  determine 
  the 
  true 
  relations 
  of 
  

   the 
  globostellate 
  spicule 
  to 
  the 
  sponge, 
  which 
  Mr. 
  Carter 
  appears 
  

   not 
  to 
  have 
  felt 
  quite 
  safe 
  in 
  regarding 
  as 
  really 
  belonging 
  to 
  

   it. 
  As, 
  however, 
  I 
  find 
  it 
  to 
  occur 
  not 
  only 
  in 
  the 
  cortex 
  of 
  dif- 
  

   ferent 
  parts 
  of 
  the 
  same 
  sponge 
  and 
  in 
  different 
  specimens, 
  but 
  

   sometimes 
  also 
  in 
  the 
  sarcode 
  beneath 
  the 
  crust 
  of 
  balls, 
  it 
  must 
  be 
  

   regarded 
  as 
  truly 
  a 
  production 
  of, 
  and 
  thus 
  proper 
  to, 
  the 
  sponge 
  

   itself. 
  I 
  find, 
  what 
  Mr. 
  Carter 
  does 
  not 
  describe, 
  a 
  small 
  acerate 
  

   spicule 
  which 
  forms 
  small 
  tufts 
  on 
  the 
  surface, 
  generally 
  accom- 
  

   panied 
  by 
  the 
  globostellate, 
  and 
  probably 
  related 
  specially 
  to 
  the 
  

   orifices 
  of 
  the 
  canal-system. 
  Like 
  Mr. 
  Carter, 
  I 
  have 
  been 
  unable 
  

   to 
  find 
  any 
  " 
  anchors." 
  

  

  My 
  measurements 
  of 
  the 
  spicules 
  do 
  not 
  quite 
  correspond 
  with 
  those 
  

   given 
  by 
  Mr. 
  Carter 
  ; 
  but 
  as 
  these 
  do 
  not 
  quite 
  agree 
  with 
  his 
  figures, 
  

   I 
  do 
  not 
  attach 
  much 
  importance 
  to 
  the 
  discrepancy. 
  In 
  his 
  descrip- 
  

   tion 
  the 
  globostellate 
  has 
  the 
  same 
  diameter 
  (viz. 
  j^^^ 
  inch) 
  assigned 
  

   to 
  it 
  as 
  to 
  the 
  shafts 
  of 
  the 
  zone-spicule 
  and 
  body 
  acerate, 
  whereas 
  

   in 
  the 
  plate, 
  where 
  it 
  is 
  figured 
  (at 
  fig. 
  /) 
  as 
  on 
  the 
  same 
  scale 
  

   (" 
  scale 
  D," 
  magnified 
  32 
  diameters) 
  as 
  those 
  spicules, 
  it 
  appears 
  as 
  

   only 
  about 
  one 
  third 
  of 
  their 
  diameter. 
  

  

  The 
  following 
  are 
  the 
  chief 
  spicular 
  measurements 
  from 
  the 
  pre- 
  

   sent 
  specimens 
  :• 
  — 
  • 
  

  

  1. 
  Zone-spicule 
  (the 
  arms 
  of 
  which 
  are 
  simple, 
  as 
  in 
  Mr. 
  Carter's 
  

   figure, 
  not 
  trifid) 
  : 
  diameter 
  of 
  shaft 
  -07 
  millim., 
  of 
  arm 
  at 
  base 
  

   about 
  '048 
  millim. 
  ; 
  expanse 
  of 
  any 
  two 
  arms 
  together 
  about 
  

   •58 
  millim. 
  

  

  2. 
  Body 
  acerate, 
  3"0 
  millim. 
  long 
  by 
  "038 
  thick. 
  

  

  3. 
  Fork 
  (the 
  only 
  one 
  seen) 
  : 
  diameter 
  of 
  arms 
  and 
  shaft 
  

   •016 
  millim. 
  ; 
  length 
  of 
  arm 
  1 
  millim. 
  

  

  4. 
  Geodia-ball, 
  long 
  diameter 
  -09 
  millim. 
  

  

  5. 
  Globostellate, 
  diameter 
  -028 
  millim. 
  

  

  6. 
  "External" 
  stellate 
  (forming, 
  with 
  the 
  globostellate, 
  the 
  outer 
  

   pellicle, 
  but, 
  like 
  it, 
  also 
  occurring 
  sparingly 
  in 
  the 
  subcortical 
  

   sarcode), 
  •0063 
  millim. 
  in 
  diameter. 
  Its 
  arms 
  are 
  numerous 
  and 
  

   appear 
  to 
  end 
  bluntly. 
  

  

  7. 
  " 
  Internal 
  " 
  stellate 
  (the 
  arms 
  are 
  few 
  in 
  number 
  and 
  are 
  

   usually 
  curved), 
  -038 
  millim. 
  in 
  diameter. 
  

  

  8. 
  Surface 
  acerate; 
  about 
  '16 
  millim. 
  long 
  by 
  -005 
  millim. 
  in 
  

   diameter. 
  

  

  The 
  largest 
  specimen 
  is 
  about 
  80 
  millim. 
  (3-i 
  inches) 
  in 
  its 
  greatest 
  

   diameter 
  ; 
  and 
  the 
  two 
  specimens 
  (which 
  are 
  preserved 
  in 
  spirit) 
  are 
  

   tinged 
  with 
  crimson 
  in 
  places, 
  as 
  if 
  this 
  was 
  their 
  colour 
  during 
  life. 
  

  

  Hah. 
  Port 
  Darwin, 
  north 
  coast 
  of 
  Australia, 
  near 
  tide-marks 
  ; 
  

   bottom 
  sand 
  and 
  rock. 
  

  

  Distribution. 
  Gulf 
  of 
  Manaar, 
  Ceylon 
  {Carter). 
  

  

  The 
  great 
  interest 
  of 
  this 
  species 
  has 
  induced 
  me 
  to 
  devote 
  some 
  

  

  