﻿8P0NGIIDA. 
  

  

  429 
  

  

  longer 
  than 
  broad, 
  inner 
  margins 
  truncate, 
  as 
  seen 
  from 
  front, 
  

   tubercle 
  distinct; 
  shaft 
  slightly 
  and 
  gradually 
  curved; 
  size 
  -01 
  G 
  

   millim. 
  long 
  : 
  abundant, 
  especially 
  in 
  dermal 
  membraue. 
  (4) 
  Tri- 
  

   curvate, 
  smooth, 
  strong, 
  the 
  curves 
  bold, 
  the 
  points 
  sharp 
  ; 
  size 
  -15 
  

   by 
  "OuG 
  millim. 
  

  

  Hah. 
  Prince 
  of 
  Wales 
  Channel, 
  Torres 
  Straits, 
  7 
  fms. 
  ; 
  bottom 
  

   sand. 
  

  

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

   broad 
  by 
  75 
  high 
  by 
  40 
  thick 
  at 
  present 
  base 
  ; 
  it 
  is 
  almost 
  semi- 
  

   circular 
  in 
  outline, 
  the 
  round 
  margin 
  uppermost 
  ; 
  it 
  appears 
  to 
  have 
  

   been 
  torn 
  from 
  a 
  rather 
  larger 
  specimen. 
  

  

  The 
  presence 
  of 
  a 
  tibiella 
  with 
  smooth 
  ends 
  distinguishes 
  it 
  from 
  

   all 
  allied 
  species 
  of 
  Desmacidon 
  (Schmidt) 
  but 
  D. 
  emj^hysema, 
  Schmidt 
  

   (JB. 
  Comm. 
  Unters. 
  deutsch. 
  Meer. 
  ii.-iii. 
  p. 
  118), 
  and 
  B. 
  physa 
  (id. 
  

   /. 
  c), 
  the 
  latter 
  of 
  which, 
  however, 
  has 
  the 
  surface 
  of 
  the 
  sponge 
  

   even 
  and 
  the 
  sponge 
  itself 
  flask-shaped 
  ; 
  in 
  the 
  former 
  the 
  sponge 
  is 
  

   covered 
  with 
  bubble-like 
  elevations. 
  Desmacidon 
  arciferum, 
  Schmidt, 
  

   which 
  has 
  a 
  similar 
  tibiella, 
  appears 
  to 
  be 
  an 
  OphJitisponijia, 
  from 
  

   the 
  strong 
  horny 
  fibre 
  and 
  the 
  echinating 
  arrangement 
  of 
  some 
  of 
  

   its 
  acuates. 
  D. 
  diance, 
  id., 
  has, 
  besides, 
  the 
  tridentate 
  anchoratcs 
  of 
  

   Ml/.villa 
  and 
  a 
  strongly 
  horny 
  fibre 
  ; 
  and 
  both 
  it 
  and 
  B. 
  anceps, 
  

   id., 
  possess 
  the 
  forcipiform 
  spicules 
  which 
  occur 
  in 
  Haliclwndria 
  

   forcij.ns, 
  Bk. 
  

  

  64. 
  Ampliilectus 
  hispidulus. 
  

   (Plate 
  XL. 
  tig. 
  C 
  ; 
  Plate 
  XLI. 
  tigs, 
  y-y".) 
  

  

  Erect, 
  clathrous 
  ; 
  formed 
  of 
  a 
  number 
  of 
  irregularly 
  branching 
  

   and 
  anastomosing 
  masses, 
  their 
  surface 
  more 
  or 
  less 
  covered 
  with 
  

   low 
  cylindrical 
  or 
  ridge-like 
  elevations. 
  Vents 
  ? 
  Surface 
  hispid 
  with 
  

   closely 
  set, 
  hair-like 
  terminations 
  of 
  the 
  primary 
  skeleton-fibres. 
  

   Texture 
  of 
  sponge 
  in 
  dry 
  state 
  firm, 
  elastic, 
  but 
  readily 
  torn, 
  in 
  

   spirit 
  soft, 
  elastic 
  ; 
  colour 
  dull 
  pale 
  brown 
  in 
  dry 
  state, 
  in 
  spirit 
  

   pale 
  pinkish 
  brown. 
  

  

  Main 
  skeleton 
  of 
  the 
  type 
  known 
  as 
  " 
  isodictyal," 
  viz. 
  consisting 
  

   of 
  primary 
  lines 
  running 
  straight 
  to 
  the 
  surface, 
  at 
  right 
  angles 
  to 
  

   it, 
  connected 
  by 
  numerous 
  transverse 
  secondary 
  lines 
  set 
  at 
  right 
  

   angles 
  to 
  the 
  piimaries; 
  distance 
  between 
  primaries 
  at 
  surface 
  

   about 
  "25 
  millim., 
  between 
  secondaries 
  '17 
  millim., 
  length 
  of 
  the 
  

   surface 
  processes 
  of 
  primaries 
  about 
  -3 
  millim. 
  Fibres 
  formed 
  of 
  

   pale 
  yellow 
  horny 
  material, 
  cored 
  by 
  the 
  axial 
  spicules 
  (no. 
  1) 
  to 
  

   the 
  extent 
  of 
  about 
  one 
  third 
  of 
  their 
  total 
  thickness 
  in 
  the 
  case 
  of 
  

   the 
  secondary 
  fibres, 
  about 
  three 
  quarters 
  in 
  the 
  primaries 
  ; 
  margins 
  

   of 
  horny 
  material 
  clearly 
  seen 
  outside 
  the 
  spicules, 
  except 
  in 
  the 
  

   surface-tufts 
  of 
  the 
  primaries, 
  which 
  arc 
  opaque 
  and 
  dark-coloured 
  ; 
  

   spicules 
  in 
  series 
  of 
  3. 
  or 
  4 
  in 
  the 
  primary, 
  of 
  2 
  in 
  the 
  secondary 
  

   fibres, 
  of 
  about 
  6 
  in 
  the 
  dermal 
  tufts 
  of 
  the 
  primaries. 
  Dermal 
  

   skeleton 
  consisting 
  of 
  an 
  irregular 
  reticulation 
  with 
  polygonal 
  

   meshes 
  made 
  up 
  of 
  fibres, 
  some 
  of 
  which 
  resemble 
  the 
  primaries, 
  

  

  