﻿56 
  A 
  MONOGRAPH 
  OF 
  THE 
  VICTORIAN 
  SPONGES. 
  

  

  Specimen 
  D. 
  (PL 
  X., 
  Fig. 
  2.) 
  

  

  (1) 
  Triradiates.- 
  — 
  Dermal. 
  Kegular, 
  large 
  and 
  stout. 
  Rays 
  conical 
  or 
  

   slightly 
  fusiform, 
  gradually 
  and 
  sharply 
  pointed, 
  measuring 
  0-3 
  by 
  

   0-035 
  mm., 
  or 
  a 
  little 
  less. 
  Deep. 
  Regular, 
  rays 
  slender, 
  conical, 
  

   fairly 
  sharp-pointed, 
  measuring 
  about 
  0*14 
  by 
  0*0085 
  mm. 
  

  

  (2.) 
  Quadriradiates. 
  — 
  Of 
  about 
  the 
  same 
  size 
  and 
  shape 
  as 
  the 
  deep 
  

   triradiates, 
  but 
  with 
  an 
  apical 
  ray 
  projecting 
  at 
  right 
  angles 
  from 
  the 
  

   centre. 
  The 
  apical 
  ray 
  is 
  usually 
  straight, 
  not 
  quite 
  so 
  long 
  as 
  the 
  

   others, 
  very 
  slender 
  and 
  finely 
  pointed, 
  slightly 
  fusiform. 
  There 
  are 
  

   also 
  a 
  few 
  larger 
  quadriradiates 
  amongst 
  the 
  dermal 
  spicules. 
  

  

  The 
  spicules 
  of 
  the 
  oscular 
  membrane 
  are, 
  as 
  usual, 
  distinctly 
  sagittal, 
  with 
  

   backwardly 
  curved 
  oral 
  rays. 
  

  

  From 
  the 
  above 
  details 
  it 
  will 
  be 
  seen 
  that 
  the 
  variation 
  in 
  spiculation 
  concerns 
  

   chiefly 
  the 
  dermal 
  triradiates, 
  the 
  rays 
  of 
  which 
  range 
  from 
  0-15 
  by 
  0'014 
  to 
  0*3 
  by 
  

   0-035 
  mm., 
  and 
  the 
  quadriradiates, 
  which 
  are 
  sometimes 
  scarce 
  and 
  sometimes 
  

   abundant, 
  with 
  the 
  apical 
  ray 
  variously 
  developed. 
  In 
  all 
  specimens 
  the 
  spicules 
  of 
  

   the 
  oscular 
  membrane 
  tend 
  to 
  become 
  markedly 
  sagittal 
  and 
  a 
  similar 
  state 
  of 
  things 
  

   is 
  sometimes 
  observable 
  around 
  the 
  pseudopores. 
  

  

  {d.) 
  Affinities.— 
  Thi^ 
  species 
  would 
  come, 
  of 
  course, 
  under 
  the 
  genus 
  Ascaltis 
  of 
  

   Hteckel's 
  system, 
  but 
  I 
  know 
  of 
  no 
  other 
  species 
  which 
  resembles 
  it 
  sufficiently 
  

   closely 
  to 
  demand 
  special 
  notice. 
  The 
  sagittal 
  triradiates 
  and 
  quadriradiates 
  in 
  the 
  

   neighbourhood 
  of 
  the 
  oscula 
  appear 
  to 
  be 
  very 
  characteristic. 
  

  

  {e.) 
  Locality. 
  ~^Q?,Y 
  Port 
  Phillip 
  Heads. 
  (Coll. 
  J. 
  B. 
  Wilson.) 
  

  

  8. 
  Lciicosolenia 
  cavata, 
  Carter, 
  sp. 
  

  

  (PL 
  II., 
  Fig. 
  7 
  ; 
  PL 
  V. 
  Figs. 
  1, 
  2 
  ; 
  PL 
  VI., 
  Figs. 
  4, 
  5 
  ; 
  PL 
  IX., 
  Fig. 
  4.) 
  

  

  Clathrina 
  cavata, 
  Carter. 
  Annals 
  and 
  Magazine 
  of 
  Natural 
  History, 
  June, 
  

   1886, 
  p. 
  502. 
  

  

  (a.) 
  General 
  Appearance 
  and 
  Canal 
  System.—TlhQ 
  sponge 
  (PL 
  II., 
  Fig. 
  7) 
  forms 
  

   massive 
  colonies 
  of 
  considerable 
  size 
  and 
  with 
  a 
  fairly 
  even 
  surface. 
  The 
  colony 
  

   grows 
  vertically 
  upwards, 
  and 
  is 
  conspicuously 
  flattened 
  on 
  the 
  top 
  and 
  generally 
  

   also 
  more 
  or 
  less 
  flattened 
  from 
  side 
  to 
  side, 
  sometimes 
  very 
  much 
  so. 
  The 
  lowest 
  

   portion 
  of 
  the 
  colony, 
  attached 
  to 
  the 
  substratum, 
  consists 
  of 
  a 
  number 
  of 
  separate, 
  

   slender 
  Ascon-tubes 
  ; 
  the 
  greater 
  part 
  is, 
  however, 
  enclosed 
  in 
  a 
  common 
  external 
  

  

  