﻿SPONGIIDA, 
  463 
  

  

  forms 
  compose 
  the 
  main 
  bulk 
  of 
  the 
  skeleton. 
  (2) 
  Long 
  smooth 
  

   acuate, 
  generally 
  slightly 
  curved, 
  tai")cring 
  gradually 
  to 
  a 
  lino 
  point 
  ; 
  

   size 
  about 
  1-1 
  by 
  -0127 
  millim. 
  : 
  forming 
  part 
  of 
  longitudinal 
  

   skoletou-lines 
  of 
  surface-tufts. 
  

  

  Hah. 
  Thursday 
  Island 
  and 
  Prince 
  of 
  Wales 
  Channel, 
  Torres 
  

   Straits, 
  4-7 
  fms. 
  

  

  Distrihuiion. 
  " 
  African 
  coasts 
  ? 
  " 
  (^Lamarck). 
  

  

  As 
  pointed 
  out 
  in 
  speaking 
  of 
  the 
  characters 
  of 
  the 
  ends 
  of 
  the 
  

   branches, 
  this 
  form 
  shows 
  considerable 
  variability 
  : 
  as 
  a 
  rule 
  the 
  

   specimens 
  are 
  chiefly 
  branched 
  in 
  one 
  plane 
  (fan-like), 
  but 
  in 
  two 
  

   specimens 
  branches 
  project 
  from 
  both 
  faces, 
  but 
  they 
  then 
  tend 
  to 
  

   form 
  fan-shaped 
  fronds 
  parallel 
  to 
  the 
  main 
  frond. 
  The 
  largest 
  

   specimen 
  measures 
  160 
  millim. 
  (6| 
  inches) 
  high 
  by 
  160 
  millim. 
  

   wide 
  ; 
  the 
  average 
  maximum 
  diameter 
  of 
  the 
  distinct 
  branches 
  

   (which 
  are 
  cylindrical 
  or 
  somewhat 
  compressed), 
  not 
  that 
  of 
  the 
  

   l3roade8t 
  but 
  obviously 
  compound 
  branches 
  (which 
  occur 
  commonly), 
  

   is 
  about 
  10-12 
  millim. 
  Five 
  specimens 
  occurred. 
  

  

  91. 
  Acanthella, 
  sp. 
  

  

  Externally 
  resembling 
  Spongia 
  cardims, 
  Lamarck 
  (Ann. 
  Mus. 
  

   Hist. 
  Nat. 
  XX. 
  p. 
  381). 
  When 
  guided 
  by 
  the 
  description 
  alone, 
  

   1 
  had 
  referred 
  the 
  present 
  specimen 
  to 
  this 
  species 
  with 
  more 
  con- 
  

   fidence 
  than 
  usual 
  ; 
  but 
  on 
  mounting 
  sections 
  of 
  the 
  probable 
  type 
  

   specimen 
  at 
  Paris, 
  I 
  saw 
  that 
  it 
  was 
  a 
  different 
  species. 
  The 
  

   points 
  in 
  which 
  the 
  description 
  does 
  not 
  quite 
  suit 
  this 
  form 
  are 
  

   " 
  pedicule 
  cylindrace, 
  tres-dur," 
  the 
  stem 
  having 
  apparently 
  been 
  

   flatfish, 
  and, 
  though 
  stiff", 
  not 
  inflexible 
  ; 
  and 
  " 
  coulour 
  d'un 
  blanc 
  

   grisatre," 
  whereas 
  this 
  (in 
  spirit) 
  is 
  flesh- 
  colour. 
  The 
  ridges 
  run 
  

   longitudinally 
  up 
  and 
  down 
  the 
  sponge, 
  and 
  are 
  1 
  to 
  3 
  millim. 
  high, 
  

   and 
  their 
  free 
  edge 
  is 
  beset 
  with 
  sharp 
  (in 
  spirit 
  flexible) 
  points 
  at 
  

   intervals 
  of 
  one 
  or 
  two 
  millimetres. 
  Texture 
  tough 
  and 
  flexible, 
  

   substance 
  compact, 
  surface 
  between 
  inequalities 
  glabrous. 
  It 
  is 
  a 
  

   true 
  Acanthella. 
  The 
  spiculation 
  is 
  as 
  follows 
  : 
  — 
  (1) 
  Smooth 
  acuate, 
  

   slightly 
  curved, 
  tapering 
  gradually 
  to 
  sharp 
  point, 
  about 
  -4 
  to 
  '6 
  

   millim. 
  by 
  -0095 
  millim. 
  (2) 
  Smooth 
  undulating 
  cylindrical 
  with 
  

   rounded 
  ends, 
  length 
  about 
  -7 
  millim., 
  diameter 
  just 
  •0063 
  millim. 
  

  

  The 
  species 
  differs 
  from 
  the 
  Adriatic 
  forms 
  A. 
  acuta 
  and 
  obtusa, 
  

   Schmidt, 
  in 
  the 
  broad 
  explanate 
  form 
  and 
  in 
  the 
  smaller 
  size 
  of 
  

   the 
  spicules, 
  the 
  cylindrical 
  being 
  much 
  shorter 
  and 
  thinner, 
  the 
  

   acuate 
  much 
  shorter 
  than 
  in 
  those 
  species. 
  The 
  skeleton 
  forms 
  

   a 
  loose-fibred 
  AxineUa-likG 
  network 
  of 
  spicules, 
  imbedded 
  in 
  a 
  

   dense, 
  transparent, 
  almost 
  colourless 
  mass 
  of 
  caoutchouc-like 
  con- 
  

   sistency, 
  containing 
  nucleoid 
  bodies 
  about 
  -007 
  to 
  '008 
  miUim. 
  in 
  

   diameter. 
  

  

  Hab. 
  Prince 
  of 
  Wales 
  Channel, 
  Torres 
  Straits, 
  7 
  fms. 
  

  

  A 
  single 
  specimen 
  in 
  spirit, 
  35 
  miUim. 
  (If 
  inch) 
  high 
  by 
  29 
  

   miUim. 
  across. 
  

  

  