﻿SPONGIIDA. 
  611 
  

  

  finely 
  hispid 
  surface 
  aud 
  the 
  low 
  irregularlj^ 
  lobate 
  form, 
  together 
  

   with 
  the 
  spicular 
  characters, 
  they 
  agree 
  closely 
  with 
  the 
  Australian 
  

   specimen, 
  but 
  the 
  average 
  diameter 
  of 
  the 
  lobes 
  is 
  somewhat 
  less 
  

   (about 
  10 
  millim,). 
  

  

  Hah. 
  Providence 
  Reef, 
  Mascarene 
  Islands, 
  24 
  fms. 
  

  

  Distribution. 
  Port 
  Darwin. 
  

  

  33. 
  Esperia 
  gelatinosa. 
  (Plate 
  LIY. 
  figs./-/"".) 
  

  

  Low 
  incrusting 
  masses, 
  frequently 
  involving 
  foreign 
  bodies, 
  

   occasionally 
  rising 
  into 
  slender 
  lobes. 
  Surface 
  in 
  spirit 
  undulating, 
  

   glabrous. 
  Consistence 
  tough, 
  elastic, 
  firm. 
  Colour 
  pale 
  greenish 
  

   grey 
  or 
  pinkish 
  brown 
  ; 
  general 
  appearance 
  gelatinous, 
  semi-trans- 
  

   parent. 
  

  

  Main 
  skeleton 
  rather 
  confused 
  in 
  the 
  incrusting 
  specimens 
  ; 
  the 
  

   vertical 
  lines 
  near 
  the 
  surface 
  being 
  short, 
  broad, 
  loose, 
  and 
  

   closely 
  approximated 
  ; 
  in 
  thicker 
  specimens 
  the 
  ordinary 
  Esperian 
  

   distinct 
  spiculo-fibres 
  appear 
  at 
  some 
  distance 
  below 
  the 
  surface 
  ; 
  

   primaries 
  crossed 
  by 
  more 
  or 
  less 
  numerous 
  detached 
  skeleton- 
  

   spicules. 
  Dermal 
  skeleton 
  composed 
  of 
  confusedly 
  intercrossing 
  

   spicules 
  not 
  arranged 
  into 
  spiculo-fibrous 
  reticulation. 
  Sarcode 
  very 
  

   pale 
  yellow, 
  transparent. 
  

  

  Spicules: 
  — 
  (1) 
  Skeleton 
  subspinulate 
  ; 
  head 
  oval, 
  slightly 
  but 
  

   distinctly 
  demarcated 
  from 
  shaft, 
  about 
  two 
  thirds 
  the 
  maximum 
  

   diameter 
  of 
  the 
  latter 
  ; 
  shaft 
  tapering 
  rather 
  abruptly 
  to 
  sharp 
  

   point 
  ; 
  size 
  of 
  spicule 
  'S 
  by 
  '016 
  millim. 
  (2) 
  Large 
  inequianchorate 
  ; 
  

   large 
  end 
  moderately 
  broad, 
  about 
  half 
  the 
  total 
  length 
  of 
  the 
  spicule, 
  

   tubercle 
  long, 
  lower 
  angles 
  of 
  outer 
  palms 
  slightly 
  rounded 
  ; 
  smaU 
  

   end 
  subtriangular, 
  rather 
  small, 
  pointed 
  below, 
  tubercle 
  small, 
  

   tongue-shaped, 
  a 
  small 
  reverted 
  margin 
  extending 
  as 
  far 
  as 
  the 
  

   tubercle 
  in 
  the 
  middle 
  ; 
  size 
  of 
  spicule 
  -06 
  by 
  -0032 
  millim. 
  (3) 
  Small 
  

   inequianchorate, 
  large 
  end 
  about 
  three 
  fifths 
  the 
  total 
  length 
  of 
  

   the 
  spicule; 
  shaft 
  aud 
  arms 
  weU 
  but 
  gradually 
  curved, 
  tubercle 
  

   short 
  ; 
  lesser 
  end 
  very 
  small, 
  not 
  prolonged 
  below 
  into 
  a 
  point; 
  length 
  

   of 
  spicule 
  -019 
  millim. 
  (4) 
  Bihamate, 
  contort, 
  slender, 
  well 
  curved, 
  

   sharp-pointed 
  ; 
  size 
  -057 
  by 
  -002 
  millim. 
  (5) 
  Trichites 
  in 
  oblong 
  

   compact 
  bundles 
  about 
  '02 
  millim. 
  long 
  and 
  "0063 
  to 
  -0075 
  millim. 
  

   in 
  diameter 
  ; 
  spicules 
  approximately 
  straight. 
  Extremely 
  abundant. 
  

  

  Hah. 
  Providence 
  Reef 
  and 
  Providence 
  Island, 
  Mascarene 
  group, 
  

   19-24 
  fms. 
  ; 
  bottom, 
  sand 
  or 
  dead 
  coral. 
  

  

  The 
  longest 
  lobes 
  are 
  20-30 
  millim. 
  long 
  and 
  3-6 
  millim. 
  in 
  

   diameter. 
  In 
  habit, 
  spiculation, 
  and 
  arrangement 
  of 
  skeleton 
  it 
  

   much 
  resembles 
  E. 
  IcBvis, 
  Carter 
  (Ann. 
  & 
  Mag, 
  N. 
  H. 
  1882, 
  ix. 
  p. 
  291, 
  

   pi. 
  xi. 
  fig. 
  16), 
  from 
  Yenczuela, 
  aud 
  E. 
  pellucida, 
  mihi 
  (Part 
  I., 
  p. 
  437, 
  

   of 
  this 
  Report) 
  ; 
  but 
  the 
  small 
  inequianchorate 
  here 
  has 
  not 
  the 
  

   terminal 
  point 
  described 
  by 
  Carter, 
  and 
  the 
  trichites 
  are 
  much 
  

   smaller 
  (-02 
  miUim. 
  instead 
  of 
  '067 
  millim. 
  long) 
  ; 
  from 
  E.jiellucida 
  

   it 
  differs 
  in 
  the 
  small, 
  short, 
  (quadrangular 
  trichite-bundles, 
  in 
  the 
  

   smaller 
  size 
  of 
  the 
  anchorates, 
  &c. 
  The 
  species 
  is 
  quite 
  abundant, 
  

   though 
  no 
  large 
  specimens 
  were 
  found. 
  

  

  2r2 
  

  

  