﻿SPONGIIBA. 
  451 
  

  

  the 
  proportions 
  of 
  the 
  spicule. 
  Ehlers 
  (Espersch. 
  Spoug.) 
  assigns 
  

   a 
  bihamate 
  to 
  that 
  species 
  *. 
  

  

  80. 
  Ehaphidophlus 
  procerus. 
  (Plate 
  XXXIX. 
  fig. 
  K 
  ; 
  

   Plate 
  XLII. 
  figs, 
  o-o" 
  .) 
  

  

  Erect, 
  cylindrical, 
  or 
  very 
  slightly 
  compressed. 
  Stem 
  tapering 
  to 
  

   a 
  point 
  above, 
  commencing 
  with 
  a 
  cylindrical 
  approximately 
  smooth 
  

   basal 
  portion, 
  about 
  millim. 
  in 
  diameter; 
  it 
  gradually 
  increases 
  in 
  

   diameter 
  towards 
  the 
  middle, 
  where 
  the 
  antero-posterior 
  diameter 
  

   is 
  7, 
  the 
  lateral 
  diameter 
  8 
  millim. 
  ; 
  the 
  lateral 
  surfaces 
  show 
  a 
  

   tendency 
  to 
  develop 
  a 
  succession 
  of 
  low 
  upwardly-projecting 
  emi- 
  

   nences 
  ; 
  the 
  anterior 
  and 
  posterior 
  surfaces 
  of 
  this 
  (middle) 
  division 
  

   of 
  the 
  sponge 
  are 
  covered 
  with 
  closely-set 
  rounded 
  papillse, 
  1-2 
  

   millim. 
  apart, 
  1 
  millim. 
  broad 
  by 
  '5 
  to 
  1 
  millim. 
  high 
  ; 
  the 
  upper 
  

   fourth 
  tapers 
  gradually 
  to 
  the 
  apex 
  and 
  is 
  approximately 
  smooth, 
  

   the 
  papillae 
  of 
  the 
  median 
  part 
  becoming 
  gradually 
  obsolete 
  here. 
  

   No 
  true 
  branches 
  (only 
  two 
  small 
  cylindrical 
  processes 
  on 
  one 
  

   side 
  close 
  together, 
  near 
  the 
  middle). 
  Base 
  formed 
  by 
  several 
  

   branched 
  roots, 
  3 
  to 
  5 
  millim. 
  in 
  diameter. 
  Surface 
  smooth 
  between 
  

   and 
  over 
  eminences, 
  compact, 
  soft 
  and 
  velvet-like 
  to 
  the 
  touch 
  ; 
  no 
  

   vents 
  visible 
  to 
  the 
  naked 
  eye. 
  Texture 
  in 
  spirit 
  firm, 
  very 
  slightly 
  

   compressible, 
  flexible, 
  very 
  tough 
  ; 
  colour 
  pale 
  grey. 
  

  

  Main 
  skeleton 
  consisting 
  of 
  a 
  close 
  network 
  of 
  amber-coloured 
  

   horny 
  or 
  dull 
  subopaque 
  yellow 
  horny 
  sarcodic 
  fibre, 
  the 
  primary 
  

   lines 
  of 
  which 
  are 
  about 
  "2 
  millim. 
  apart 
  and 
  are 
  placed 
  vertically 
  

   to 
  the 
  surface, 
  the 
  secondaries 
  also 
  about 
  "2 
  millim 
  apart, 
  crossing 
  

   the 
  intervals 
  between 
  the 
  primaries 
  at 
  approximately 
  right 
  angles 
  ; 
  

   to 
  the 
  fibres 
  are 
  attached 
  by 
  their 
  bases 
  large 
  numbers 
  of 
  the 
  larger 
  

   smooth 
  spinulate 
  spicule, 
  whose 
  points 
  project 
  outwards 
  and 
  upwards 
  

   at 
  acute 
  angles 
  to 
  the 
  fibre. 
  Dermal 
  skeleton 
  formed 
  of 
  a 
  single 
  

   thickness 
  of 
  distinct, 
  but 
  overlapping, 
  dense 
  tufts 
  of 
  the 
  smaller 
  

   smooth 
  spinulate 
  spicule, 
  one 
  or 
  more 
  of 
  the 
  spined 
  acuate 
  spicules 
  

   occupying 
  the 
  centre 
  of 
  each 
  tuft 
  ; 
  the 
  spicid.es 
  are 
  attached 
  by 
  

   their 
  blunt 
  ends, 
  and 
  the 
  points 
  radiate 
  outwards 
  over 
  the 
  dermis. 
  

   Sarcode 
  pale 
  yellowish 
  brown, 
  somewhat 
  granular. 
  

  

  Spicules 
  : 
  — 
  (1) 
  Smooth 
  spinulate 
  ; 
  head 
  distinct, 
  suboval, 
  rather 
  

   narrower 
  than 
  middle 
  of 
  shaft 
  ; 
  shaft 
  tapering 
  gradually 
  to 
  sharp 
  

   point 
  from 
  about 
  middle; 
  size 
  "36 
  by 
  '0127 
  millim: 
  in 
  fibre 
  of 
  

   main 
  skeleton. 
  (2) 
  As 
  (1), 
  but 
  measuring 
  •28 
  by 
  '0079 
  millim.; 
  

   forming 
  tufts 
  in 
  dermis. 
  (3) 
  Spined 
  acuate, 
  with 
  well-rounded, 
  un- 
  

   dilated 
  base, 
  tapering 
  to 
  sharp 
  point 
  from 
  base 
  ; 
  spines 
  usually 
  

   absent 
  from 
  the 
  apex 
  and 
  just 
  above 
  base, 
  stout, 
  sharp, 
  those 
  of 
  

   median 
  portion 
  of 
  spicule 
  more 
  or 
  less 
  recurvate 
  towards 
  base 
  ; 
  size 
  

   •11 
  by 
  '0127: 
  in 
  centre 
  of 
  dermal 
  tufts 
  and 
  sparingly 
  in 
  main-skeleton 
  

  

  * 
  Spongia 
  cactiformis, 
  Lamarck 
  (Ann. 
  Mus. 
  Hist. 
  Nat. 
  xx. 
  p. 
  440), 
  is 
  also 
  a 
  

   Ehaphidophlus, 
  differing 
  from 
  R. 
  arborcscens, 
  so 
  far 
  as 
  the 
  material 
  at 
  my 
  die- 
  

   posal 
  shows, 
  mainly 
  in 
  the 
  non-spinulation 
  of 
  the 
  smooth 
  acuate. 
  

  

  2g2 
  

  

  