﻿382 
  COLLECTIONS 
  FROM 
  MELANESIA. 
  

  

  fibres 
  rounded-angled 
  meshes, 
  "14 
  to 
  -21 
  millim. 
  in 
  diameter, 
  between 
  

   the 
  primaries, 
  which 
  are 
  about 
  •■i2 
  millim. 
  apart. 
  Skeleton-fibres 
  

   amber-yellow 
  in 
  colour, 
  usually 
  homogeneous 
  in 
  appearance 
  through- 
  

   out. 
  Primaries 
  cored 
  to 
  some 
  little 
  distance 
  from 
  surface 
  by 
  a 
  

   usuallj' 
  single 
  series 
  of 
  small 
  foreign 
  bodies 
  : 
  secondaries 
  uncored. 
  

   Sarcode 
  dull 
  pale 
  brown, 
  subtransparent. 
  Texture 
  of 
  sponge 
  in 
  

   spirit 
  very 
  tough 
  and 
  elastic. 
  

  

  Hah. 
  Alert 
  Island, 
  Torres 
  Straits, 
  7 
  fms. 
  

  

  [^Distribution. 
  " 
  Australian 
  Seas 
  " 
  {LcunarcJc) 
  ?] 
  

  

  HIPPOSPONGIA. 
  

  

  Sclmhe, 
  Zeitsch. 
  luiss. 
  Zool. 
  xxxii. 
  p. 
  614. 
  

  

  Under 
  this 
  head, 
  owing 
  to 
  the 
  sheet-like 
  aggregation 
  of 
  the 
  

   skeleton-fibres 
  on 
  the 
  different 
  surfaces, 
  and 
  the 
  large 
  tubular 
  cavi- 
  

   ties 
  formed 
  by 
  the 
  excretory 
  canals, 
  I 
  am 
  for 
  the 
  present 
  including 
  

   those 
  Spongiidae 
  with 
  maeaudrine 
  main 
  excretory 
  canals, 
  as 
  Caco- 
  

   spongia 
  cavernosa., 
  Esper, 
  and 
  Spongia 
  intestinalis, 
  Lamarck, 
  as 
  a 
  

   subdivision 
  of 
  the 
  genus. 
  Characters 
  may, 
  perhaps, 
  in 
  the 
  future 
  

   be 
  discovered 
  in 
  their 
  soft 
  parts 
  to 
  justify 
  their 
  separation 
  from 
  

   that 
  genus. 
  The 
  following 
  is 
  a 
  third 
  species 
  referable 
  to 
  this 
  sec- 
  

   tion 
  of 
  Hippospongia. 
  

  

  5. 
  Hippospongia 
  derasa*. 
  (Plate 
  XLI. 
  fig. 
  A.) 
  

  

  Sponge 
  subglobose 
  ; 
  surface 
  and 
  interior 
  of 
  skeleton 
  honeycombed 
  

   by 
  meeandering 
  and 
  branching 
  excretory 
  canals 
  2 
  to 
  3 
  millim. 
  in 
  

   diameter 
  at 
  the 
  surface, 
  opening 
  into 
  larger 
  s])aces 
  at 
  a 
  short 
  distance 
  

   within 
  the 
  sponge. 
  Texture 
  of 
  sponge 
  firm, 
  but 
  elastic, 
  in 
  dry 
  

   state 
  ; 
  colour 
  buff, 
  becoming 
  ochreous 
  in 
  parts. 
  

  

  Skeleton 
  at 
  surface 
  between 
  openings 
  of 
  canals 
  smooth 
  and 
  com- 
  

   pact, 
  as 
  if 
  pared 
  by 
  a 
  knife 
  ; 
  walls 
  of 
  canals 
  smooth. 
  Primary 
  fibres 
  

   simple, 
  straight, 
  either 
  ( 
  1 
  ) 
  cored 
  and 
  set 
  at 
  right 
  angles 
  to 
  surface, 
  but 
  

   not 
  projecting 
  beyond 
  it, 
  diameter, 
  where 
  not 
  distended 
  by 
  foreign 
  

   bodies, 
  -05 
  millim. 
  ; 
  or 
  (2) 
  not 
  cored 
  by 
  foreign 
  bodies, 
  set 
  a2:)prox- 
  

   imately 
  at 
  right 
  angles 
  to 
  cored 
  primaiies, 
  diameter 
  about 
  '035 
  

   millim. 
  Secondaries 
  forming 
  either 
  subrectangular 
  or 
  irregular 
  

   meshes 
  between 
  the 
  primaries 
  ; 
  diameter 
  -018 
  to 
  '022 
  millim. 
  

   Diameter 
  of 
  the 
  ultimate 
  meshes 
  -07 
  to 
  -14 
  millim. 
  ; 
  distance 
  be- 
  

   tween 
  primary 
  fibres 
  "IS 
  millim. 
  Fibre 
  dense, 
  homogeneous, 
  elastic 
  ; 
  

   colour 
  pale 
  amber-yellow. 
  

  

  Hah. 
  West 
  Island, 
  Torres 
  Straits 
  (washed 
  up). 
  

  

  The 
  single 
  dry 
  specimen 
  is 
  subhemisphcrical, 
  and 
  measures 
  60 
  

   millim. 
  (2|- 
  inches) 
  in 
  length 
  by 
  35 
  millim. 
  {l\ 
  inch) 
  in 
  height. 
  

   The 
  species 
  is 
  most 
  nearly 
  allied 
  to 
  H. 
  (Sjjongia) 
  intestinalis, 
  La- 
  

   marck, 
  but 
  has 
  the 
  fibres 
  only 
  about 
  two 
  thirds 
  the 
  stoutness 
  of 
  

   those 
  of 
  that 
  species, 
  and 
  it 
  is 
  subglobose 
  instead 
  of 
  being 
  elongated 
  

   and 
  tubular. 
  The 
  texture 
  of 
  intestinalis 
  is 
  coarser 
  and 
  harsher 
  

   than 
  that 
  of 
  this 
  species, 
  partly 
  owing 
  to 
  the 
  thickness 
  of 
  the 
  fibres 
  

  

  * 
  Drrado, 
  to 
  rub 
  down, 
  in 
  allusion 
  to 
  the 
  smootbiiess 
  and 
  compact 
  texture 
  

   of 
  the 
  Burf'ace. 
  

  

  