﻿SPONGIIDA. 
  403 
  

  

  and 
  Australian 
  specimens 
  have 
  rather 
  thicker 
  branches 
  than 
  those 
  

   from 
  the 
  Straits 
  of 
  Malacca, 
  viz. 
  12 
  to 
  25 
  millim. 
  as 
  against 
  about 
  

   10 
  millim. 
  

  

  Hub. 
  Prince 
  of 
  Wales 
  Channel 
  and 
  Thursday 
  Island, 
  Torres 
  

   'Straits, 
  beach 
  and 
  7-9 
  fms. 
  ; 
  Port 
  Darwin, 
  7-12 
  fms. 
  

  

  Distribution. 
  Straits 
  of 
  Malacca 
  {Boiuerbanlc) 
  ; 
  New 
  Guinea 
  

   (^BowcrbanJc 
  coll.). 
  

  

  33. 
  Toxochalina 
  rohiista. 
  (Plate 
  XXXIX. 
  fig. 
  G 
  ; 
  

   Plate 
  XLI, 
  figs, 
  n, 
  n 
  .) 
  

  

  Eepent, 
  branching, 
  attached 
  usually 
  by 
  the 
  lower 
  surface 
  of 
  the 
  

   main 
  stem 
  or 
  branches. 
  Stem 
  and 
  branches 
  subcylindrical, 
  uneven 
  

   in 
  places, 
  subnodular, 
  varying 
  in 
  diameter 
  within 
  short 
  distances 
  ; 
  

   solid, 
  not 
  tubular. 
  Branches 
  given 
  off 
  at 
  intervals 
  of 
  1 
  to 
  2 
  

   inches, 
  at 
  angles 
  of 
  from 
  about 
  30° 
  to 
  80°, 
  sometimes 
  anastomosing. 
  

   Stem 
  and 
  main 
  branches 
  usually 
  10 
  to 
  18 
  millim. 
  in 
  greatest 
  

   diameter, 
  some 
  small 
  branches 
  descend 
  to 
  4 
  and 
  5 
  millim. 
  Vents 
  

   few, 
  approximately 
  one 
  to 
  the 
  space 
  between 
  each 
  two 
  branches, 
  

   the 
  margins 
  usually 
  sharp 
  and 
  projecting 
  somewhat 
  ; 
  diameter 
  

   3 
  to 
  G 
  millim. 
  ; 
  excretory 
  canals 
  penetrating 
  straight 
  and 
  deeply 
  

   into 
  the 
  substance 
  of 
  the 
  sponge. 
  Sponge, 
  in 
  spirit, 
  tough, 
  but 
  

   yielding 
  and 
  pliable 
  (almost 
  as 
  much 
  so 
  as 
  ChaJina 
  oculata, 
  Pallas). 
  

   Internal 
  fibres 
  soft 
  and 
  elastic, 
  forming 
  a 
  close 
  network. 
  Dermal 
  

   membrane 
  firmer, 
  parchment-like, 
  even, 
  glabrous, 
  slightly 
  marked 
  

   by 
  the 
  apices 
  of 
  the 
  primary 
  skeleton-fibres 
  and 
  the 
  dermal 
  skeleton- 
  

   network. 
  Colour 
  of 
  sponge 
  in 
  spirit 
  pale 
  brown, 
  inclined 
  to 
  yellow. 
  

   Main 
  skeleton 
  consisting 
  of 
  straight, 
  stout, 
  bright 
  amber-yellow, 
  

   horny 
  primary 
  fibres, 
  "05 
  to 
  "075 
  millim. 
  thick, 
  and 
  about 
  -5 
  to 
  "7 
  

   millim. 
  apart 
  at 
  surface, 
  meeting 
  the 
  siu'face 
  at 
  right 
  angles, 
  and 
  

   sometimes 
  projecting 
  slightly 
  ; 
  their 
  apices 
  are, 
  however, 
  connected 
  

   by 
  a 
  system 
  of 
  fine 
  horizontal 
  fibre-network 
  ; 
  sjiicules 
  closely 
  aggre- 
  

   gated, 
  confined 
  to 
  the 
  axis 
  of 
  fibre, 
  forming 
  a 
  band 
  there 
  of 
  about 
  

   6 
  to 
  8 
  spicules 
  broad, 
  and 
  occupying, 
  near 
  the 
  surface 
  of 
  the 
  sponge, 
  

   only 
  about 
  one 
  third 
  of 
  the 
  total 
  thickness 
  of 
  the 
  fibre. 
  Secondary 
  

   fibres 
  at 
  right 
  angles 
  to 
  primaries, 
  of 
  paler 
  yellow 
  horny 
  fibre, 
  about 
  

   •035 
  to 
  -05 
  millim. 
  in 
  diameter 
  and 
  -28 
  to 
  -35 
  millim. 
  apart; 
  

   spicules 
  of 
  axis 
  in 
  a 
  unispicular 
  series 
  (occasionally 
  two 
  spicules 
  

   broad), 
  often 
  interrupted 
  altogether 
  or 
  wholly 
  wanting. 
  Dermal 
  

   skeleton 
  formed 
  by 
  a 
  few 
  very 
  stout, 
  dark 
  yellow 
  fibres, 
  "05 
  to 
  •! 
  

   millim. 
  thick 
  and 
  1 
  to 
  1*4 
  millim. 
  apart, 
  enclosing 
  angular 
  spaces 
  

   filled 
  by 
  a 
  close 
  subrectangular 
  network 
  of 
  paler, 
  mostly 
  non-spicu- 
  

   late 
  fibres 
  from 
  -009 
  to 
  •045 
  millim. 
  in 
  diameter. 
  Sarcode 
  very 
  pale 
  

   yellow, 
  transparent, 
  with 
  numerous 
  small 
  dark 
  granules. 
  

  

  Skeleton- 
  spicule 
  acerate, 
  tapering 
  abruptly 
  from 
  within 
  about 
  1| 
  

   diameters 
  of 
  ends 
  to 
  very 
  sharp 
  points 
  ; 
  size 
  •I 
  by 
  ^0032 
  to 
  -0042 
  

   millim. 
  Flcsh-spicule 
  tricurvate 
  acerate, 
  curves 
  moderately 
  bold, 
  

   tapering 
  gradually 
  to 
  sharp 
  points 
  from 
  centre 
  ; 
  size 
  ^05 
  to 
  •063 
  by 
  

   •0017 
  to 
  ^0021 
  millim. 
  ; 
  found 
  in 
  superficial 
  and 
  deeper 
  parts 
  of 
  the 
  

   sponge, 
  fairly 
  abundant. 
  

  

  Hab. 
  Port 
  Jackson, 
  0-5 
  fms. 
  

  

  2d2 
  

  

  