﻿SPOXGIIDA. 
  445 
  

  

  Torres 
  Straits 
  specimen. 
  

  

  1. 
  Slender 
  acuate 
  (slightly 
  

  

  inflated 
  basally) 
  -25 
  to 
  -31 
  by 
  -0042 
  to 
  -005 
  millim. 
  

  

  2. 
  Stout 
  long 
  acuate 
  (very 
  

  

  scarce) 
  About 
  -19 
  by 
  -0095. 
  

  

  3. 
  Spined 
  echinating 
  acu- 
  

  

  ate 
  -085 
  by 
  -0044. 
  

  

  4. 
  Equianchorate 
  -014 
  to 
  -016 
  long. 
  

  

  Hah. 
  Prince 
  of 
  Wales 
  Channel, 
  Thursday 
  Island, 
  &c., 
  Torres 
  

   Straits, 
  4-10 
  fms. 
  ; 
  bottom 
  sand 
  &c. 
  ; 
  common. 
  

  

  From 
  stiidy 
  of 
  the 
  present 
  series 
  of 
  specimens, 
  with 
  the 
  light 
  

   aiforded 
  by 
  W. 
  Marshall's 
  important 
  paper, 
  " 
  Untersuchungen 
  iiber 
  

   D3sideiden 
  und 
  Phoriospongien" 
  (Zeitsch.wiss. 
  Zoo], 
  xxxv. 
  p. 
  122), 
  

   I 
  am 
  now 
  convinced 
  that 
  Bowerbank 
  was 
  right 
  in 
  describing 
  the 
  

   arenaceous 
  material 
  which 
  is 
  so 
  plentifully 
  present 
  in 
  this 
  sponge 
  

   as 
  the 
  normal 
  substratum 
  of 
  the 
  skeleton-lines, 
  and 
  that 
  it 
  does 
  not, 
  

   as 
  I 
  formerly 
  considered 
  (P.Z.S. 
  1881, 
  p. 
  122), 
  consist 
  of 
  the 
  tubes 
  

   of 
  an 
  arenaceous 
  Foraminifer. 
  That 
  being 
  so, 
  the 
  character 
  assumes 
  

   a 
  fresh 
  importance 
  when 
  it 
  is 
  seen 
  not 
  to 
  stand 
  alone 
  among 
  the 
  

   Siliceous 
  Sponges. 
  PAorzospom/m, 
  Marshall 
  {l.c.\ 
  is 
  described 
  as 
  

   having 
  a 
  spiculation 
  consisting 
  of 
  acei'ate 
  and 
  (or) 
  spinulate 
  and 
  

   bihamate 
  spicules 
  in 
  combination 
  with 
  a 
  large 
  quantity 
  of 
  sand, 
  the 
  

   latter, 
  however, 
  not 
  aggregated 
  into 
  definite 
  fibres. 
  With 
  regard 
  to 
  

   Clatliria 
  tuberosa, 
  though 
  it 
  diff'ers 
  from 
  other 
  Clathrice 
  in 
  this 
  

   remarkable 
  point, 
  its 
  spiculation 
  is 
  distinctly 
  that 
  of 
  the 
  genus 
  to 
  

   which 
  I 
  propose 
  to 
  refer 
  it. 
  

  

  76. 
  Clathria 
  coppingeri. 
  

   (Plate 
  XL. 
  figs. 
  F, 
  F' 
  ; 
  Plate 
  XLII. 
  figs, 
  i, 
  i' 
  .) 
  

  

  Erect, 
  palmate, 
  clathrous, 
  groAving 
  in 
  only 
  one 
  plane. 
  A 
  few 
  

   main 
  branches 
  are 
  given 
  off 
  from 
  the 
  common 
  base 
  or 
  rudimentary 
  

   stem, 
  each 
  dividing 
  furcately 
  once 
  or 
  twice 
  at 
  acute 
  angles 
  ; 
  the 
  

   terminal 
  branches 
  are 
  traceable 
  to 
  within 
  about 
  two 
  thirds 
  of 
  the 
  

   distance 
  from 
  the 
  base 
  to 
  the 
  periphery 
  of 
  the 
  sponge. 
  All 
  the 
  

   branches 
  intimately 
  united 
  by 
  a 
  close 
  reticulation, 
  consisting 
  of 
  bars 
  

   of 
  sponge-substance, 
  suboblong 
  in 
  transverse 
  section, 
  the 
  longest 
  

   diameter 
  being 
  the 
  antero-postcrior 
  one, 
  the 
  anterior 
  and 
  posterior 
  

   surface 
  of 
  the 
  bars 
  either 
  flat 
  or 
  coming 
  to 
  an 
  angle 
  in 
  front 
  or 
  

   behind 
  or 
  on 
  both 
  aspects 
  ; 
  the 
  surface 
  of 
  the 
  sponge 
  thus 
  presents 
  

   a 
  series 
  of 
  subquadrangular, 
  polygonal, 
  or 
  suboval 
  cells, 
  having 
  

   a 
  maximum 
  diameter 
  of 
  3 
  to 
  10 
  millim. 
  Main 
  branches 
  suboblong 
  

   in 
  transverse 
  section, 
  the 
  antero-posterior 
  diameter 
  being 
  longer 
  

   than 
  the 
  lateral 
  one 
  : 
  slightly 
  marked 
  by 
  longitudinal 
  furrows, 
  the 
  

   anterior 
  and 
  posterior 
  faces 
  flat 
  or 
  angular 
  ; 
  the 
  branches 
  (espe- 
  

   cially 
  the 
  larger 
  ones) 
  project 
  above 
  the 
  level 
  of 
  the 
  intermediate 
  

   reticulation, 
  owing 
  to 
  their 
  superior 
  antero-posterior 
  thickness, 
  which 
  

   attains 
  a 
  maximum 
  of 
  20 
  millim., 
  the 
  lateral 
  diameter 
  a 
  maximum 
  

   of 
  10 
  millim. 
  Surface 
  of 
  intermediate 
  reticulation, 
  sides 
  of 
  main 
  

  

  