﻿A 
  MONOGEAPH 
  OF 
  THE 
  VICTORIAN 
  SPONGES. 
  65 
  

  

  to 
  which 
  of 
  the 
  various 
  forms 
  inchided 
  by 
  Haeckel 
  under 
  the 
  name 
  loculosa 
  that 
  name 
  

   should 
  be 
  restricted. 
  None 
  of 
  these 
  forms 
  are 
  figured 
  and 
  none 
  are 
  specially 
  

   described, 
  but 
  the 
  first 
  mentioned 
  is 
  the 
  SolenisaLs, 
  hence 
  I 
  propose 
  to 
  restrict 
  the 
  name 
  

   loculosa 
  io 
  ^ 
  Solenisms 
  form. 
  It 
  must 
  be 
  remembered, 
  in 
  considering 
  Hfeckel's 
  

   account, 
  that 
  his 
  term 
  "•Exodcrni' 
  includes 
  both 
  ectoderm 
  and 
  mesoderm. 
  Although 
  

   HaBckel 
  found 
  embryos 
  he 
  does 
  not 
  appear 
  to 
  have 
  noticed 
  the 
  curious 
  embryo- 
  

   capsules 
  which 
  are 
  so 
  conspicuous 
  in 
  Leiicosolenia 
  wilsoui, 
  perhaps 
  they 
  do 
  not 
  occur 
  

   in 
  any 
  of 
  Haeckel's 
  forms, 
  if 
  so 
  they 
  might 
  form 
  a 
  distinctive 
  character 
  for 
  Leucosolenia 
  

   wilsoui. 
  

  

  Haeckel's 
  Ascetta 
  clathrina^ 
  also 
  exhibits 
  the 
  same 
  peculiarity 
  in 
  regard 
  to 
  the 
  

   subdivision 
  of 
  the 
  Ascon-tubes 
  by 
  ingrowths 
  of 
  mesoderm 
  and 
  endoderm 
  

   (" 
  endogastriche 
  Septa," 
  Hk.), 
  but 
  in 
  that 
  species, 
  which 
  Haeckel 
  regards 
  as 
  a 
  variety 
  

   of 
  Ascetta 
  clathrus, 
  the 
  rays 
  of 
  the 
  spicules 
  are 
  knobbed 
  at 
  the 
  extremities. 
  

  

  The 
  affinities 
  of 
  Leucosoleuia 
  wilsoui 
  to 
  L. 
  proxiuia 
  have 
  already 
  been 
  indicated 
  

   in 
  describing 
  the 
  latter 
  species. 
  

  

  {e.) 
  Locality.— 
  ^(t^x 
  Port 
  Phillip 
  Heads. 
  (Coll. 
  J. 
  B. 
  Wilson.) 
  

  

  13. 
  Le7tcosolcuia 
  dcprcssa, 
  n. 
  sp. 
  

  

  (PI. 
  HI., 
  Figs. 
  4, 
  4a 
  ; 
  PI. 
  VHI., 
  Fig. 
  8 
  ; 
  PI. 
  XL, 
  Fig. 
  4.) 
  

  

  [a.) 
  Geueral 
  Appearaucc 
  aud 
  Caual 
  System. 
  — 
  The 
  single 
  specimen 
  (PL 
  IH., 
  Figs. 
  

   4, 
  4a) 
  forms 
  a 
  flattened, 
  spreading, 
  irregular 
  crust, 
  attached 
  to 
  the 
  substratum 
  (if 
  at 
  

   all) 
  at 
  a 
  few 
  points 
  only. 
  The 
  greatest 
  diameter 
  of 
  the 
  specimen 
  is 
  a 
  little 
  over 
  

   100 
  mm. 
  and 
  the 
  average 
  thickness 
  about 
  10 
  mm. 
  or 
  less. 
  The 
  surface 
  is 
  smooth 
  

   but 
  irregular 
  and 
  undulating. 
  On 
  the 
  upper 
  surface 
  are 
  scattered 
  numerous 
  very 
  

   small, 
  conical 
  papillae, 
  each 
  with 
  a 
  very 
  minute 
  osculum 
  at 
  its 
  summit. 
  On 
  the 
  

   upper 
  surface 
  also 
  the 
  psendoderm 
  is 
  very 
  strongly 
  develo])ed, 
  witli 
  comparativ(>ly 
  fcnv, 
  

   small 
  pseudo])ores 
  scattered 
  in 
  irregular 
  patches 
  hero 
  and 
  there. 
  On 
  tlu^ 
  undcM- 
  

   surface, 
  on 
  the 
  other 
  hand, 
  the 
  pseudoporos 
  are 
  larger 
  and 
  tliickly 
  scatter(>d 
  all 
  over, 
  

   giving 
  to 
  it 
  a 
  sieve-like 
  a})pearance. 
  In 
  spirit 
  the 
  colour 
  of 
  tlu^ 
  spong(> 
  is 
  greyish 
  

   white. 
  

  

  The 
  canal 
  system 
  is 
  like 
  that 
  of 
  Leucosoleuia 
  wilsoui 
  (tyi)e 
  F), 
  but 
  witli 
  th(^ 
  

   ingrowths 
  into 
  the 
  gastral 
  cavities 
  of 
  the 
  Ascon-tubes 
  more 
  irregular 
  and 
  less 
  strongly 
  

   develo])ed, 
  consisting 
  prhici])ally 
  of 
  irr(>gular 
  prolifevaiions 
  of 
  the 
  endodenn. 
  

  

  * 
  " 
  Dio 
  Knlkschvviimmp," 
  Vol. 
  2, 
  ji. 
  31. 
  

  

  