﻿370 
  COLLECTIONS 
  FROM 
  MELANESIA. 
  

  

  that 
  in 
  other 
  species 
  as 
  well 
  the 
  distinct 
  cloacal 
  systems 
  may 
  prove 
  

   to 
  be 
  formed 
  in 
  the 
  same 
  manner. 
  In 
  his 
  latest 
  work 
  (Spong. 
  

   Meerbus. 
  Mexico) 
  Schmidt 
  says 
  (p. 
  16) 
  : 
  — 
  " 
  Individuell 
  beginnend 
  

   iibernehmen 
  in 
  vielen 
  Spongien 
  die 
  anfanglich 
  neutralcii 
  oder 
  gemeiu- 
  

   schaftlichen 
  Gebietc 
  die 
  Tlolle 
  der 
  Individuen, 
  aber 
  der 
  sich 
  ndli- 
  

   rende 
  und 
  fortpJlanzendeKorper 
  ist 
  iveder 
  Individuum 
  nocli 
  ein 
  Stocic, 
  

   auch 
  der 
  blosse 
  Vergleich 
  mit 
  Individuum 
  und 
  Stock 
  passt 
  nicht 
  auf 
  

   ihn." 
  (The 
  italics 
  are 
  Prof. 
  Schmidt's.) 
  This 
  view 
  would 
  seem 
  to 
  

   hold 
  well, 
  at 
  any 
  rate 
  in 
  the 
  cases 
  I 
  have 
  referred 
  to. 
  

  

  Parasitism. 
  — 
  An 
  instance 
  of 
  an 
  Oscillatorian 
  Alga 
  parasitic 
  within 
  

   the 
  tissues 
  of 
  a 
  Sponge 
  is 
  described 
  under 
  Stelletta 
  clavosa 
  ; 
  a 
  similar 
  

   circumstance 
  has 
  been 
  recorded 
  in 
  Halisarca 
  and 
  /S/jo;ir/t-Z?rt 
  (Schulze) 
  

   and 
  in 
  a 
  Suberite 
  (Carter). 
  Two 
  examples 
  are 
  to 
  be 
  noted 
  of 
  the 
  

   converse 
  case, 
  viz. 
  that 
  of 
  a 
  Sponge 
  constantly 
  employing 
  an 
  Alga 
  for 
  

   support 
  by 
  mingling 
  with 
  its 
  structures, 
  as 
  already 
  noticed 
  by 
  Semper 
  

   in 
  Sjjongia 
  eartilaginea, 
  Esper, 
  These 
  cases 
  are 
  — 
  (1) 
  Gellius 
  cymi- 
  

   fonnis 
  (v. 
  infra), 
  where 
  the 
  Sponge, 
  though 
  probably 
  less 
  in 
  bulk 
  

   than 
  the 
  Alga, 
  seems 
  to 
  draw 
  the 
  latter 
  into 
  its 
  own 
  form 
  ; 
  and 
  

   (2) 
  a 
  Renierid 
  (probably 
  Reniera 
  s. 
  str.) 
  from 
  Port 
  Molle, 
  Q.uc"ens- 
  

   land, 
  which 
  coats 
  and 
  penetrates 
  between 
  the 
  superficial 
  fibres 
  of 
  

   two 
  specimens 
  of 
  a 
  species 
  of 
  erect 
  arborescent 
  Alga, 
  giving 
  it 
  the 
  

   appearance 
  of 
  the 
  British 
  Sponge 
  Halicliondria 
  albescens. 
  

  

  A 
  few 
  examjiles 
  of 
  Sjiowiiophaga 
  (Carter) 
  were 
  noticed 
  in 
  the 
  

   basal 
  part 
  of 
  a 
  spirit-specimen 
  of 
  a 
  llhaphidopldus 
  {R. 
  procera) 
  from 
  

   Port 
  Darwin 
  : 
  the 
  heads 
  measured 
  -005 
  to 
  "01 
  millim., 
  the 
  fibre 
  

   about 
  '001 
  millim. 
  in 
  diameter. 
  This 
  parasite 
  has 
  already 
  been 
  

   recorded 
  from 
  the 
  Siliceous 
  genera 
  AxiaeUa, 
  Gellius, 
  Esperia, 
  Vioa 
  

   (Carter, 
  Ann. 
  cfeMag. 
  N. 
  H. 
  (5) 
  ii. 
  p. 
  167). 
  It 
  also 
  occurs 
  in 
  the 
  Cera- 
  

   tosa 
  of 
  the 
  collection 
  ; 
  the 
  skeleton 
  of 
  a 
  Hircinia 
  from 
  Torres 
  Straits 
  

   is 
  almost 
  replaced 
  by 
  it. 
  

  

  Geographical 
  Distribution. 
  

   1. 
  Relations 
  of 
  Australia 
  to 
  other 
  Districts. 
  

  

  In 
  attempting 
  to 
  compare 
  the 
  Australian 
  Sponge-fauna 
  with 
  the 
  

   faunas 
  of 
  other 
  districts, 
  we 
  are 
  met 
  by 
  a 
  great 
  difficulty, 
  caused 
  by 
  the 
  

   very 
  imperfect 
  manner 
  in 
  which 
  the 
  Ceratose 
  and 
  Siliceous 
  Sponges 
  

   of 
  any 
  given 
  marine 
  region, 
  except 
  the 
  Northern 
  and 
  Equatorial 
  

   Atlantic 
  and 
  Mediterranean, 
  are 
  as 
  yet 
  known. 
  A 
  paper 
  by 
  Prof. 
  

   Sclenka 
  (Zeitsch. 
  wiss. 
  Zool. 
  xxxii. 
  p. 
  467) 
  and 
  one 
  by 
  myself 
  

   (Proc. 
  Zool. 
  Soc. 
  1881, 
  p. 
  107)give 
  accounts 
  of 
  about 
  30 
  species 
  irom 
  

   the 
  South 
  Atlantic; 
  Esper, 
  Carter, 
  and 
  Vosmaer 
  describe 
  species 
  from 
  

   the 
  Cape. 
  The 
  Sponges 
  of 
  the 
  Pacific 
  are 
  almost 
  wholly 
  unknown*. 
  

   Thanks 
  almost 
  exclusively 
  to 
  Mr. 
  Carter's 
  and 
  Dr. 
  Bowerbauk's 
  exer- 
  

   tions, 
  we 
  have 
  a 
  better 
  knowledge 
  of 
  the 
  Indian-Ocean 
  fauna 
  ; 
  but 
  

   even 
  this 
  is 
  extremely 
  imperfect. 
  Our 
  more 
  exact 
  knowledge 
  of 
  this 
  

   area 
  (excluding 
  Australia, 
  for 
  which 
  see 
  above, 
  p. 
  366) 
  is 
  based 
  

   chiefly 
  on 
  :— 
  

  

  * 
  But 
  soe 
  Carter's 
  (Ann. 
  & 
  Mag. 
  Nat. 
  Hist.) 
  and 
  Bowerbank's 
  (Proc. 
  Zool. 
  

   Soc.) 
  writings 
  for 
  sundry 
  species 
  from 
  the 
  " 
  South 
  Seas;" 
  and 
  Doderlein 
  (Zeitsch. 
  

   wiss. 
  Zool. 
  xl. 
  p. 
  G2) 
  tor 
  ibur 
  new 
  Lithistidffl 
  from 
  Japan. 
  

  

  