﻿440 
  COLLECTIONS 
  FROM 
  MELANESIA. 
  

  

  shallow 
  depressions, 
  covered 
  by 
  a 
  glabrous 
  semitransparent 
  mem- 
  

   brane, 
  rendered 
  rough 
  by 
  the 
  projection 
  of 
  the 
  low 
  ends 
  of 
  the 
  

   primary 
  fibres, 
  •25 
  to 
  '5 
  millim, 
  apart 
  (many 
  smooth 
  patches 
  occur) 
  ; 
  

   texture 
  in 
  spirit 
  brittle, 
  compressible 
  (specimen 
  No. 
  1), 
  rather 
  tough, 
  

   elastic 
  (specimen 
  No. 
  2) 
  ; 
  colour 
  pale 
  greyish 
  (specimen 
  No. 
  1) 
  or 
  

   reddish 
  brown 
  (specimen 
  No. 
  2). 
  Internal 
  structure 
  cavernous, 
  

   loose. 
  Vents 
  numerous, 
  scattered, 
  circular 
  or 
  oval, 
  leading 
  deeply 
  

   into 
  sponge 
  ; 
  diameter 
  1-5 
  to 
  3 
  millim. 
  

  

  Main 
  skeleton 
  regular, 
  rectangular 
  ia 
  arrangement 
  ; 
  primary 
  

   fibres 
  set 
  at 
  right 
  angles 
  to 
  surface, 
  '18 
  to 
  '35 
  millim. 
  apart, 
  OlS 
  

   to 
  '03 
  millim. 
  thick 
  ; 
  secondary 
  fibres 
  at 
  right 
  angles 
  to 
  primaries, 
  

   •18 
  to 
  ^35 
  millim. 
  or 
  upwards 
  ajjart, 
  similar 
  to 
  primaries 
  in 
  propor- 
  

   tions 
  ; 
  fibres 
  wholly 
  composed 
  of 
  foreign 
  bodies 
  united 
  by 
  an 
  almost 
  

   colourless, 
  not 
  dense, 
  substance. 
  Dermal 
  skeleton 
  formed 
  by 
  small 
  

   foreign 
  bodies 
  scattered 
  abundantly 
  over 
  the 
  dermis, 
  tending 
  to 
  

   aggregate 
  into 
  slightly 
  denser 
  anastomosing 
  tracts 
  about 
  "14 
  millim. 
  

   broad, 
  enclosing 
  rounded 
  meshes 
  about 
  ^18 
  to 
  ^53 
  millim. 
  in 
  dia- 
  

   meter, 
  and 
  by 
  the 
  cylindrical 
  spicules 
  of 
  the 
  sponge, 
  which 
  by 
  loose 
  

   aggregation 
  form 
  tracts, 
  about 
  4 
  to 
  6 
  spicules 
  broad, 
  below 
  the 
  

   skeleton 
  of 
  foreign 
  bodies, 
  the 
  tracts 
  branching 
  and 
  anastomosing 
  

   not 
  unfrequently, 
  and 
  ending 
  freely 
  on 
  the 
  surface 
  in 
  slightly 
  

   expanding 
  tufts 
  ; 
  sarcode 
  subtransparent, 
  granular, 
  colour 
  a 
  warm 
  

   brown 
  (slightly 
  in 
  specimen 
  No. 
  1 
  , 
  strongly 
  in 
  specimen 
  No. 
  2, 
  in 
  

   which 
  it 
  is 
  more 
  dense. 
  Spicules: 
  — 
  (1) 
  Slender 
  acerate, 
  smooth, 
  with 
  

   very 
  slightly 
  enlarged 
  subpyriform 
  basal 
  end, 
  the 
  other 
  end 
  rather 
  

   bluntly 
  pointed 
  ; 
  size 
  about 
  •IG 
  to 
  •lO 
  by 
  •0021 
  by 
  ^0032 
  millim. 
  : 
  

   forming 
  part 
  of 
  dermal 
  skeleton 
  and 
  scattered 
  over 
  main 
  skeleton- 
  

   fibres. 
  (2) 
  Contort 
  bihamate, 
  smooth, 
  curve 
  moderately 
  strong, 
  

   points 
  sharp, 
  suddenly 
  and 
  sharply 
  bent 
  inwards 
  ; 
  size 
  ^032 
  by 
  ^002 
  

   millim. 
  : 
  abundant 
  in 
  subjacent 
  tissues. 
  (3) 
  Tridentate 
  equiaucho- 
  

   rate, 
  shaft 
  well 
  curved, 
  about 
  "0016 
  millim. 
  thick 
  ; 
  teeth 
  slender, 
  

   sharp, 
  curved 
  inwards, 
  about 
  "008 
  millim. 
  long 
  ; 
  spicule 
  ^022 
  millim. 
  

   long. 
  Foreign 
  bodies 
  small 
  in 
  specimen 
  No. 
  1 
  ; 
  large, 
  for 
  the 
  most 
  

   part, 
  in 
  specimen 
  No. 
  2. 
  

  

  Hab. 
  Specimen 
  No. 
  1 
  : 
  Prince 
  of 
  "Wales 
  Channel, 
  Torres 
  Straits, 
  

   7-9 
  fms. 
  ; 
  bottom 
  sand. 
  Specimen 
  No. 
  2 
  : 
  Port 
  Jackson, 
  0-5 
  fms. 
  

   Two 
  specimens 
  in 
  spirit. 
  No. 
  1 
  has 
  apparently 
  been 
  torn 
  from 
  a 
  

   larger 
  mass 
  ; 
  it 
  is 
  much 
  penetrated 
  by 
  some 
  thin 
  Algas, 
  on 
  which 
  it 
  

   seems 
  to 
  have 
  grown 
  much 
  as 
  Amorphina 
  panicea 
  grows 
  over 
  weed 
  ; 
  

   it 
  measures 
  60 
  millim. 
  by 
  22 
  millim. 
  in 
  its 
  two 
  chief 
  dimensions. 
  

   No. 
  2 
  is 
  somewhat 
  compressed 
  on 
  one 
  side, 
  and 
  measures 
  36 
  by 
  

   19 
  by 
  12 
  millim. 
  The 
  anchorate 
  spicule 
  is 
  scarce 
  in 
  one 
  of 
  the 
  

   specimens 
  (that 
  from 
  Port 
  Jackson), 
  while 
  it 
  is 
  abundant 
  in 
  the 
  

   other. 
  

  

  The 
  variability 
  in 
  colour 
  and 
  texture, 
  and 
  i)erhaps 
  in 
  the 
  secon- 
  

   dary 
  fibres, 
  is 
  considerable, 
  but 
  not 
  surprising, 
  considering 
  the 
  

   distance 
  between 
  the 
  stations 
  at 
  which 
  the 
  specimens 
  were 
  obtained 
  ; 
  

   in 
  other 
  points 
  the 
  agreement 
  is 
  close. 
  The 
  species 
  is 
  a 
  very 
  dis- 
  

   tinct 
  one, 
  differing 
  from 
  both 
  Marshall's 
  species 
  in 
  the 
  presence 
  of 
  

   a 
  well-defined 
  reticulate 
  skeleton 
  and 
  of 
  an 
  anchorate 
  flesh-spicule. 
  

  

  