﻿62 
  A 
  MONOGBAPH 
  OF 
  THE 
  VICTOEIAN 
  SPONGES. 
  

  

  mention 
  of 
  the 
  oxeote 
  spicules, 
  but 
  as 
  I 
  find 
  them 
  present 
  in 
  one 
  of 
  his 
  type 
  

   specimens 
  sent 
  to 
  me 
  from 
  the 
  British 
  Museum 
  this 
  must 
  be 
  an 
  oversight 
  on 
  

   his 
  part. 
  

  

  {c.) 
  Locality.— 
  ^esiT 
  Port 
  Philhp 
  Heads. 
  (Coll. 
  J. 
  B. 
  Wilson.) 
  

  

  10a. 
  Lcucosolcnia 
  ventricosa 
  var. 
  solida, 
  nov. 
  

  

  (Plate 
  III., 
  Fig. 
  3.) 
  

  

  This 
  Yariet}^ 
  represented 
  in 
  the 
  collection 
  by 
  two 
  good 
  specimens, 
  differs 
  from 
  

   the 
  typical 
  form 
  in 
  the 
  flattened, 
  cake-like 
  shape 
  and 
  the 
  suppression 
  of 
  the 
  pseudogaster. 
  

   The 
  exhalant 
  canal 
  system 
  is 
  reduced 
  to 
  a 
  shallow 
  pit 
  varying 
  up 
  to 
  about 
  a 
  quarter 
  

   of 
  an 
  inch 
  in 
  diameter, 
  in 
  the 
  bottom 
  of 
  which 
  are 
  visible 
  several 
  small 
  circular 
  

   openings 
  (exhalant 
  openings 
  of 
  the 
  Ascon-tubes). 
  Around 
  this 
  pit 
  there 
  is 
  a 
  slightl}'- 
  

   developed 
  fringe. 
  Numerous 
  pits 
  of 
  this 
  kind 
  occur 
  on 
  the 
  upper 
  surface 
  of 
  each 
  

   specimen. 
  It 
  is 
  doubtful 
  whether 
  one 
  is 
  justified 
  any 
  longer 
  in 
  speaking 
  of 
  a 
  

   pseudogaster 
  and 
  pseudosculum 
  in 
  this 
  variety, 
  for 
  the 
  collared 
  cells 
  appear 
  to 
  

   approach 
  very 
  closely 
  to 
  the 
  edge 
  of 
  the 
  pit, 
  at 
  any 
  rate 
  in 
  some 
  cases. 
  Perhaps 
  it 
  

   would 
  be 
  better 
  to 
  regard 
  the 
  pits 
  as 
  groups 
  of 
  true 
  oscula 
  or 
  even 
  each 
  as 
  a 
  single 
  

   true 
  osculum 
  formed 
  by 
  the 
  union 
  of 
  many 
  Ascon-tubes. 
  Hence 
  the 
  canal 
  system 
  is 
  

   referable 
  rather 
  to 
  type 
  B 
  than 
  to 
  type 
  D. 
  

  

  In 
  spiculation 
  this 
  form 
  is 
  identical 
  with 
  Lencosolcnia 
  ventricosa 
  as 
  described 
  

   above, 
  and 
  as 
  the 
  spiculation 
  is 
  very 
  characteristic 
  I 
  therefore 
  regard 
  it 
  as 
  a 
  well- 
  

   marked 
  variety 
  of 
  that 
  species. 
  

  

  Locality.— 
  ^Qw 
  Port 
  Phillip 
  Heads. 
  (Coll. 
  J. 
  B. 
  Wilson.) 
  

  

  Subsection 
  2. 
  Snbdivisa. 
  

  

  The 
  gastral 
  cavities 
  of 
  the 
  Ascon-tubes 
  are 
  more 
  or 
  less 
  subdivided 
  into 
  

   chambers 
  by 
  ingrowths 
  of 
  mesoderm 
  or 
  of 
  l^oth 
  mesoderm 
  and 
  endoderm. 
  

  

  11. 
  Lcncosolenia 
  proxima, 
  n. 
  sp. 
  

   (PI. 
  n.. 
  Figs. 
  1, 
  2; 
  PI. 
  VIIL, 
  Figs. 
  1, 
  2, 
  3, 
  4 
  ; 
  PL 
  XL, 
  Fig. 
  2). 
  

  

  {a.) 
  General 
  Appearance 
  and 
  Canal 
  System.— 
  The 
  sponge 
  forms 
  small 
  colonies 
  

   attached 
  by 
  little, 
  solid, 
  root-like 
  processes 
  to 
  foreign 
  objects 
  [e.g. 
  Polyzoa). 
  The 
  form 
  

  

  