﻿8P0NGIIDA. 
  

  

  449 
  

  

  show 
  to 
  greater 
  advantage, 
  that 
  the 
  stag's-horn-like 
  branches 
  anas- 
  

   tomose 
  and 
  inosculate 
  very 
  freely 
  with 
  each 
  other, 
  forming 
  a 
  number 
  

   of 
  deep 
  angular 
  cells, 
  open 
  above 
  and 
  below, 
  and 
  more 
  or 
  less 
  at 
  the 
  

   sides 
  also, 
  owing 
  to 
  the 
  fenestne 
  left 
  between 
  the 
  branches. 
  The 
  

   Australian 
  specimens 
  mostly 
  exceed 
  Bowerbank's 
  type 
  in 
  their 
  

   dimensions: 
  the 
  largest 
  measures 
  110 
  millim. 
  (4|^ 
  inches) 
  by 
  115 
  

   millim. 
  (44- 
  inches) 
  in 
  extreme 
  height 
  and 
  breadth 
  respectively 
  ; 
  it 
  is 
  

   formed 
  of 
  three 
  main 
  lobes 
  which 
  arise 
  from 
  a 
  common 
  base 
  and 
  

   unite 
  towards 
  the 
  summit 
  of 
  the 
  sponge. 
  

  

  The 
  measurements 
  of 
  the 
  spicules 
  are 
  given, 
  as 
  Bowerbank 
  hfts 
  

   not 
  figured 
  them 
  : 
  — 
  

  

  Hah. 
  Thursday 
  Island, 
  4-5 
  fms. 
  ; 
  Prince 
  of 
  Wales 
  Channel, 
  

   5-7 
  fms. 
  ; 
  Percy 
  Island 
  and 
  Fitzroy 
  Island, 
  Queensland, 
  7-11 
  fms, 
  ; 
  

   bottom- 
  — 
  combinations 
  of 
  sand, 
  mud, 
  or 
  shells. 
  

  

  Distrihution. 
  Straits 
  of 
  Malacca, 
  Gaspar 
  Strait 
  (Bowerbank). 
  

  

  The 
  presence 
  of 
  spined 
  echinating 
  spicules 
  removes 
  the 
  species 
  

   from 
  AmphUectus, 
  where 
  it 
  had 
  been 
  placed 
  by 
  Vosmaer, 
  who 
  had 
  

   only 
  an 
  imperfect 
  description 
  to 
  guide 
  him. 
  It 
  must 
  be 
  referred 
  to 
  

   Clathria 
  as 
  emended 
  by 
  him 
  ; 
  and 
  it 
  is 
  interesting 
  to 
  find 
  here 
  a 
  

   variabilit)' 
  in 
  the 
  development 
  of 
  the 
  horny 
  fibre 
  in 
  difi'erent 
  speci- 
  

   mens 
  which 
  is 
  similar 
  to 
  what 
  he 
  has 
  described 
  {J. 
  c. 
  p. 
  150) 
  in 
  

   C 
  coralloides. 
  

  

  The 
  second 
  Queensland 
  specimen 
  (" 
  B 
  ''), 
  from 
  Percy 
  Island, 
  

   differs 
  decidedly 
  from 
  the 
  rest 
  in 
  the 
  greater 
  slenderness 
  of 
  its 
  

   skeleton-spicules 
  ; 
  it 
  is, 
  however, 
  a 
  young 
  specimen, 
  and 
  the 
  dif- 
  

   ferences 
  may 
  be 
  due 
  to 
  this 
  circumstance. 
  

  

  RHAPHIDOPHLUS. 
  

  

  Ehlers, 
  Die 
  Esiiersch. 
  Spong. 
  pp. 
  19, 
  31. 
  

  

  This 
  genus 
  differs 
  from 
  Clathria 
  only 
  by 
  its 
  spicular 
  crust, 
  and 
  

   from 
  Echinonema, 
  Carter, 
  only 
  by 
  the 
  absence 
  of 
  tricurvate 
  spi- 
  

   cules. 
  

  

  2q 
  

  

  