﻿Sl'ONGIIDA, 
  415 
  

  

  primary 
  fibres 
  run 
  vertically 
  to 
  surface, 
  mostly 
  into 
  the 
  surface- 
  

   points 
  ; 
  these 
  are 
  connected 
  below 
  by 
  long 
  secondary 
  fibres, 
  approxi- 
  

   mately 
  at 
  right 
  angles 
  to 
  them 
  ; 
  internal 
  skeleton 
  consisting 
  chiefly 
  of 
  

   long 
  more 
  or 
  less 
  curved 
  spiculo-fibrcs 
  and 
  membranous 
  expansions, 
  

   containing 
  non-aggregated 
  spicules, 
  surrounding 
  rounded 
  spaces. 
  

   Dermal 
  skeleton 
  formed 
  by 
  the 
  projection 
  of 
  the 
  ends 
  of 
  the 
  primary 
  

   main-skeleton 
  lines 
  ; 
  the 
  spaces 
  between 
  these 
  are 
  occupied 
  by 
  

   numerous 
  spicules 
  irregularly 
  scattered 
  over 
  the 
  membrane 
  which 
  

   covers 
  the 
  surface, 
  occasionally 
  aggregated 
  into 
  irregular 
  loose 
  pauci- 
  

   spicular 
  tracts. 
  Sarcode 
  of 
  interior 
  reddish 
  brown 
  (darkest 
  around 
  

   the 
  fibres), 
  rather 
  granular, 
  of 
  conuli 
  very 
  dark 
  opaque 
  red-brown 
  

   Spicules 
  smooth 
  acerate, 
  very 
  slightly 
  curved, 
  tapering 
  to 
  sharp 
  

   points 
  from 
  about 
  three 
  diameters 
  from 
  ends 
  ; 
  size 
  -14 
  by 
  "0063 
  

   millim. 
  

  

  Ilah. 
  Albany 
  Island, 
  Northern 
  Australia, 
  3-4 
  fms. 
  ; 
  bottom 
  

   mud. 
  

  

  A 
  specimen 
  and 
  a 
  fragment, 
  both 
  in 
  spirit, 
  the 
  former 
  45 
  millim. 
  

   (14. 
  inch) 
  high 
  by 
  40 
  millim. 
  across 
  ; 
  a 
  8cr])ida 
  is 
  imbedded 
  in 
  the 
  

   lower 
  part, 
  which 
  forms 
  (from 
  anastomosis) 
  almost 
  one 
  continuous 
  

   mass, 
  and 
  small 
  specimens 
  of 
  Serialaria 
  are 
  growing 
  on 
  it. 
  The 
  

   tenacity 
  of 
  the 
  internal 
  fibres 
  and 
  membranes 
  shows 
  the 
  presence 
  of 
  

   a 
  stronger 
  element 
  than 
  ordinary 
  sarcode 
  ; 
  but 
  horny 
  outlines 
  are 
  

   not 
  to 
  be 
  distinguished 
  on 
  the 
  fibres, 
  although 
  the 
  sarcode 
  is 
  darker 
  

   here. 
  

  

  It 
  is 
  nearly 
  allied 
  to 
  Hymcniaeidon 
  brctti 
  and 
  tJiomasi, 
  Bowerbank 
  

   (British 
  seas) 
  ; 
  but 
  the 
  spicules 
  of 
  these 
  species 
  are 
  far 
  longer 
  than 
  

   those 
  here, 
  and 
  the 
  surface-roughness 
  does 
  not 
  extend 
  to 
  the 
  pro- 
  

   duction 
  of 
  the 
  characteristic 
  hair-like 
  points 
  found 
  here, 
  which 
  

   resemble 
  those 
  of 
  Easpongia. 
  Dr. 
  Gray 
  (P. 
  Z. 
  S. 
  1867, 
  p. 
  518) 
  

   retains 
  these 
  species 
  in 
  lieniern, 
  with 
  most 
  of 
  the 
  acerate-spiculed 
  

   species 
  of 
  Hymenlacidon 
  described 
  by 
  Bowerbank 
  ; 
  Schmidt 
  (Atl. 
  

   Geb. 
  p. 
  76) 
  assigns 
  them 
  to 
  Amorphina. 
  Protoschmidtia 
  fora- 
  

   minosa, 
  Czerniavsky 
  (Bull. 
  Soc. 
  Mosc. 
  1879, 
  p. 
  98), 
  Black 
  Sea, 
  agrees 
  

   in 
  the 
  proportions 
  and 
  forms 
  of 
  its 
  spicules, 
  in 
  colour, 
  &c., 
  diff"ering 
  

   mainly 
  in 
  its 
  much 
  less 
  rough 
  surface 
  and 
  distinct 
  vents 
  ; 
  so 
  I 
  place 
  

   this 
  species 
  in 
  the 
  same 
  genus 
  in 
  preference 
  to 
  Amorpliina, 
  which, 
  

   if 
  Ilalichondna 
  panicea 
  is 
  to 
  be 
  regarded 
  as 
  typical 
  of 
  its 
  struc- 
  

   ture, 
  should 
  include 
  forms 
  with 
  a 
  distinctly 
  reticulate 
  dermal 
  

   skeleton 
  and 
  absence 
  of 
  tough 
  and 
  deeply 
  coloured 
  sarcode 
  from 
  the 
  

   fibres. 
  

  

  51 
  . 
  Schmidtia 
  variabilis. 
  (Plate 
  XXXIX. 
  fig. 
  N 
  ; 
  

   Plate 
  XLI. 
  fig. 
  t.) 
  

  

  Decumbent 
  ; 
  consisting 
  of 
  elongated 
  horizontal 
  (sometimes 
  ver- 
  

   tically 
  flattened-out) 
  lobes 
  of 
  very 
  irregular, 
  more 
  or 
  less 
  angular 
  

   outline, 
  sometimes 
  branching 
  and 
  anastomosing 
  ; 
  the 
  upper 
  margin 
  

   rises 
  at 
  intervals 
  into 
  low 
  elevations, 
  which 
  consist 
  of 
  thick-walled, 
  

   wide, 
  rounded 
  tubes, 
  3 
  to 
  7 
  millim. 
  in 
  diameter 
  at 
  the 
  mouth, 
  

   within 
  which 
  the 
  true 
  vents 
  unite 
  at 
  about 
  6 
  millim. 
  below 
  mouth 
  ; 
  

  

  