﻿436 
  COLLECTIONS 
  FROM 
  MELANESIA. 
  

  

  15 
  millim, 
  in 
  greatest 
  and 
  least 
  thicknesses 
  respeetiTOly, 
  spreading 
  

   over 
  and 
  uniting 
  three 
  detached 
  stones, 
  from 
  which 
  arise 
  two 
  chief 
  

   and 
  a 
  few 
  incipient 
  lobes, 
  the 
  largest 
  respectively 
  12 
  and 
  25 
  millim. 
  

   in 
  height. 
  The 
  species 
  differs 
  from 
  the 
  Torres-Straits 
  and 
  Malacca 
  

   species 
  (/. 
  jmrpurea) 
  in 
  the 
  presence 
  of 
  the 
  cylindrical 
  dermal 
  

   spicule, 
  in 
  the 
  stouter 
  stem, 
  and 
  the 
  much 
  more 
  finely 
  roughened 
  

   surface; 
  it 
  is 
  more 
  nearly 
  allied 
  to 
  D. 
  {Ilaruhomlria) 
  hirotnlifera, 
  

   Higgin 
  (from 
  the 
  West 
  Indies), 
  which 
  it 
  resembles 
  in 
  stoutness 
  

   of 
  habit 
  ; 
  but 
  the 
  cylindrical 
  and 
  acuate 
  spicules 
  are 
  both 
  twice 
  the 
  

   diameter 
  of 
  the 
  corresponding 
  spicules 
  of 
  that 
  form. 
  

  

  69. 
  Esperia 
  parishi. 
  

  

  Rapliiodesma 
  parisbii, 
  Boiverhank, 
  P. 
  Z. 
  S. 
  1875, 
  p. 
  283. 
  

   Amphilectus 
  parisbii, 
  Vosmaer, 
  Notes 
  Roy. 
  Mus. 
  Netherl. 
  ii. 
  p. 
  119. 
  

  

  An 
  indubitable 
  Esperia. 
  Dr. 
  Bowerbank's 
  description 
  of 
  the 
  

   spicnlation 
  of 
  this 
  species 
  is 
  defective 
  and 
  misleading 
  ; 
  he 
  omits 
  to 
  

   notice 
  the 
  sheaves 
  of 
  " 
  trichites 
  '' 
  which 
  I 
  find 
  in 
  his 
  preparations 
  ; 
  

   they 
  are, 
  as 
  usual, 
  local 
  in 
  their 
  occurrence, 
  and, 
  from 
  their 
  de- 
  

   licate 
  proportions, 
  not 
  easy 
  to 
  find 
  ; 
  the 
  slender 
  bihamates 
  described 
  

   may 
  be 
  traced 
  by 
  intermediate 
  stages 
  up 
  to 
  the 
  large 
  bihamates, 
  

   which 
  are 
  perhaps 
  the 
  most 
  striking 
  feature 
  of 
  the 
  spiculation 
  ; 
  

   they 
  are 
  thus 
  merely 
  the 
  young 
  of 
  these 
  latter 
  forms 
  : 
  the 
  alleged 
  

   spincd 
  acuates 
  and 
  tricurvates 
  obviously 
  belong 
  to 
  a 
  Myxilla 
  over 
  

   which 
  the 
  Esperia 
  has 
  grown, 
  as 
  they 
  occur 
  in 
  abundance 
  together, 
  

   but 
  not 
  all 
  over 
  the 
  " 
  basal 
  membrane." 
  (Some 
  navicular 
  equi- 
  

   anchorates 
  which 
  occur 
  seem 
  to 
  be 
  also 
  foreign, 
  being 
  found 
  only 
  

   detached 
  and 
  in 
  small 
  numbers, 
  and 
  but 
  local 
  in 
  their 
  distribution.) 
  

   I 
  am 
  inclined 
  to 
  consider 
  the 
  small 
  " 
  palraato-inequianchorates 
  " 
  as 
  

   young 
  forms 
  of 
  the 
  normal 
  large 
  one. 
  

  

  The 
  following 
  are 
  the 
  proportions 
  of 
  the 
  different 
  spicules 
  proper 
  

   to 
  the 
  sponge 
  ; 
  they 
  agree 
  fairly 
  in 
  both 
  the 
  Malacca 
  and 
  Australian 
  

   specimens 
  : 
  — 
  

  

  1. 
  Smooth, 
  subspinulate 
  acuate, 
  with 
  slight 
  elongate 
  head; 
  basal 
  

   end 
  slenderer 
  than 
  middle 
  of 
  shaft 
  : 
  ''i'd 
  by 
  '013 
  millim. 
  

  

  2. 
  Large 
  inequiauchorate 
  ; 
  large 
  end 
  comparatively 
  short, 
  its 
  

   tubercle 
  long 
  and 
  narrow^ 
  : 
  -057 
  millim. 
  long. 
  

  

  3. 
  Navicular 
  equianchorate: 
  -013 
  millim. 
  long. 
  

  

  4. 
  Bihamate, 
  smooth, 
  contort 
  : 
  -095 
  by 
  -008 
  millim. 
  

  

  5. 
  Trichite 
  spicules 
  in 
  bunches 
  of 
  two 
  to 
  four 
  or 
  five 
  : 
  -032 
  to 
  -16 
  

   by 
  -0018 
  millim. 
  

  

  Some 
  thin 
  fragments 
  agreeing 
  well 
  in 
  all 
  respects 
  with 
  the 
  typical 
  

   pecimen 
  occur 
  in 
  the 
  present 
  collection. 
  

  

  Hah. 
  Port 
  Darwin, 
  between 
  tide-marks. 
  

  

  Distrihntion. 
  Straits 
  of 
  Malacca 
  {BorverhavTc). 
  

  

  This 
  si)ecies 
  appears 
  to 
  be 
  absent 
  from 
  Torres 
  Straits, 
  judging 
  

   from 
  the 
  results 
  of 
  the 
  numerous 
  dredgings 
  taken 
  there 
  ; 
  its 
  presence 
  

   at 
  Port 
  Darwin 
  is 
  therefore 
  probably 
  to 
  be 
  accounted 
  for 
  by 
  direct 
  

   transit 
  across 
  the 
  western 
  end 
  of 
  the 
  Arafura 
  Sea 
  by 
  way 
  of 
  Timor 
  

   and 
  the 
  neighbouring 
  islands. 
  

  

  