﻿392 
  COLLECTIONS 
  PROM 
  MELANESIA. 
  

  

  granules, 
  lying 
  in 
  a 
  diffusely 
  stained 
  subtransparent 
  matrix 
  of 
  the 
  

   same 
  colour, 
  but 
  paler. 
  A 
  transparent 
  membrane, 
  consisting 
  of 
  an 
  

   almost 
  colourless 
  matrix, 
  containing 
  few 
  purple 
  granules, 
  appears 
  to 
  

   invest 
  the 
  fibre, 
  

  

  Hab. 
  Thursday 
  Island, 
  Torres 
  Straits, 
  4-5 
  fms. 
  ; 
  bottom 
  sand, 
  or 
  

   sand 
  and 
  rock. 
  

  

  Distribution. 
  " 
  Indian 
  Ocean 
  " 
  (Pallas). 
  

  

  Obs, 
  In 
  many 
  particulars 
  this 
  species 
  recalls 
  Aplysina 
  purpurea 
  of 
  

   Carter, 
  but 
  appears 
  to 
  differ 
  fundamentally 
  in 
  the 
  distinctness, 
  large 
  

   size, 
  and 
  non-multiplicity 
  of 
  the 
  fibres 
  ; 
  whereas 
  in 
  that 
  species 
  the 
  

   axes 
  of 
  the 
  conuli 
  and 
  the 
  skeleton 
  generally 
  consist 
  of 
  aggregated 
  

   masses 
  of 
  fine 
  fibrils. 
  If 
  Hyatt's 
  species 
  is 
  really 
  like 
  lantheUa 
  

   Jiomei, 
  with 
  which 
  he 
  compares 
  it, 
  it 
  cannot 
  be 
  this 
  sponge, 
  as 
  it 
  

   would 
  be 
  of 
  flattened 
  growth 
  ; 
  but 
  he 
  appears 
  to 
  be 
  uncertain 
  on 
  

   the 
  point. 
  

  

  If 
  one 
  of 
  the 
  dermal 
  cones, 
  with 
  the 
  surrounding 
  membranes, 
  is 
  

   treated 
  with 
  a 
  strong 
  solution 
  of 
  caustic 
  potash, 
  a 
  dark 
  brownish- 
  

   yellow 
  colouring-matter 
  is 
  dissolved 
  out, 
  thereby 
  differing 
  from 
  

   that 
  of 
  lantheUa, 
  which 
  is 
  said 
  to 
  be 
  violet 
  iinder 
  similar 
  circum- 
  

   stances 
  (Gray, 
  Proc. 
  Zool. 
  Soc. 
  1869, 
  p. 
  50) 
  ; 
  nothing 
  of 
  the 
  tissues 
  

   is 
  left 
  but 
  a 
  branched 
  fibre 
  or 
  two 
  and 
  some 
  flocculent 
  matter 
  ; 
  

   therefore 
  the 
  only 
  truly 
  fibrous 
  structures 
  here 
  are 
  the 
  terminal 
  

   twigs 
  of 
  the 
  skeleton. 
  

  

  The 
  wall 
  of 
  the 
  main 
  skeleton-fibre 
  of 
  this 
  species 
  is 
  much 
  thicker 
  

   than 
  in 
  most 
  ApJijsina', 
  and 
  its 
  axial 
  substance 
  is 
  not 
  granular. 
  

  

  20. 
  lanthella 
  flabelliformis. 
  

  

  Spongia 
  flabelliformis, 
  Pallas, 
  Blench. 
  Zooph. 
  p. 
  380. 
  

   lauthella 
  flabelliformis, 
  Gray, 
  P. 
  Z. 
  S. 
  1869, 
  p. 
  50. 
  

  

  A 
  specimen 
  in 
  spirit, 
  somewhat 
  imperfect, 
  and 
  not 
  showing 
  any 
  

   of 
  those 
  exfoliations 
  of 
  the 
  lateral 
  surfaces 
  which 
  specimens 
  com- 
  

   monly 
  exhibit. 
  

  

  Hab. 
  Port 
  Darwin, 
  7-12 
  fms. 
  ; 
  bottom 
  sand. 
  

  

  Distribution. 
  Indian 
  Ocean 
  (Pallas); 
  " 
  Australia 
  " 
  (G-'ra^/). 
  

  

  CHALINID^. 
  

  

  In 
  this 
  family 
  must 
  now 
  be 
  included 
  some 
  forms 
  with 
  minute 
  

   flesh-spicules. 
  Homoeoclictya, 
  Ehlers, 
  is 
  the 
  earliest 
  discovered 
  case 
  

   of 
  this 
  combination 
  ; 
  and 
  I 
  am 
  able 
  to 
  add 
  another, 
  in 
  a 
  new 
  genus, 
  

   Toxochalina, 
  which 
  possesses 
  fine 
  tricurvates 
  scattered 
  in 
  the 
  sarcode. 
  

   I 
  have 
  relegated 
  lilnzoclialina 
  to 
  the 
  Desraacidinida3 
  for 
  reasons 
  given 
  

   below 
  (family 
  Desmacidinidse). 
  I 
  have 
  also 
  given 
  reasons 
  for 
  a 
  

   belief 
  that 
  Platyclmlina, 
  Ehlers, 
  is 
  a 
  Ceratoso 
  sponge 
  (see 
  Euspongia, 
  

   supra). 
  

  

  The 
  fact 
  cannot 
  be 
  ignored 
  that 
  the 
  genus 
  Toxochalina, 
  charac- 
  

   terized 
  below, 
  runs 
  counter 
  to 
  the 
  plan 
  of 
  classification 
  hitherto 
  

  

  