﻿SPONGIIDA. 
  619 
  

  

  spicular 
  columns 
  radiating 
  horizontally 
  from 
  the 
  axial 
  skeleton, 
  but 
  

   much 
  disguised 
  by 
  crossing 
  spicules, 
  sometimes 
  united 
  into 
  secondary 
  

   fibres. 
  Axial 
  skeleton 
  — 
  the 
  longitudinal 
  lines 
  strong, 
  but 
  in 
  basal 
  

   parts 
  of 
  sponge 
  confused 
  by 
  close 
  aggregation 
  ; 
  the 
  axis 
  of 
  the 
  fla- 
  

   bellate 
  parts 
  is 
  composed, 
  on 
  the 
  contrary, 
  of 
  a 
  dense 
  mass 
  of 
  horizon- 
  

   tally 
  arranged 
  spicules, 
  from 
  which 
  the 
  short 
  dermal 
  tufts 
  project 
  

   so 
  as 
  to 
  appear 
  on 
  the 
  surface 
  of 
  the 
  sponge. 
  Bases 
  of 
  spicules 
  of 
  

   radiating 
  lines 
  and 
  much 
  of 
  the 
  entire 
  axial 
  spicular 
  columns 
  

   enveloped 
  in 
  a 
  tough 
  transparent 
  substance, 
  amber-yellow 
  in 
  dry, 
  

   salmon-colour 
  in 
  spirit-specimens. 
  

  

  Spicules 
  : 
  — 
  (1) 
  Acuate, 
  smooth, 
  curved 
  slightly 
  but 
  rather 
  abruptly 
  

   at 
  from 
  one 
  third 
  to 
  one 
  half 
  the 
  distance 
  from 
  the 
  base 
  ; 
  tapering 
  

   gradually 
  from 
  about 
  middle, 
  more 
  rapidly 
  from 
  about 
  three 
  fourths 
  

   of 
  length, 
  to 
  sharp 
  points, 
  and 
  sometimes 
  slightly 
  towards 
  base 
  ; 
  

   base 
  rather 
  squarely 
  rounded 
  ; 
  size 
  '55 
  by 
  '032 
  to 
  -O-iS 
  millim. 
  

   (forms 
  chief 
  part 
  of 
  the 
  axial 
  and 
  radial 
  columns 
  and 
  the 
  secondary 
  

   fibres). 
  (2) 
  Acuate, 
  smooth, 
  straight 
  or 
  slightly 
  curved, 
  tapering 
  

   gradually 
  to 
  fine 
  points 
  from 
  about 
  one 
  fourth 
  of 
  the 
  length 
  from 
  

   the 
  apex 
  ; 
  base 
  well 
  rounded 
  : 
  size 
  -5 
  to 
  1-8 
  by 
  '015 
  to 
  -02 
  miUim. 
  

   (sparingly, 
  in 
  company 
  with 
  no. 
  1, 
  in 
  most 
  parts 
  ; 
  especially, 
  attached 
  

   to 
  bases 
  of 
  radiating 
  columns, 
  and 
  projecting 
  outwards 
  in 
  a 
  direction 
  

   parallel 
  to 
  them). 
  

  

  Hab. 
  Providence 
  Island, 
  Mascarene 
  group, 
  18 
  and 
  19 
  fms. 
  ; 
  bottom 
  

   coral. 
  

  

  Two 
  small 
  specimens 
  in 
  spirit, 
  one 
  large 
  dried 
  dredged 
  specimen, 
  

   and 
  two 
  medium-sized 
  beach-worn 
  specimens 
  represent 
  the 
  species 
  ; 
  

   the 
  largest 
  measures 
  120 
  millim. 
  (5 
  inches) 
  in 
  both 
  greatest 
  height 
  ' 
  

   and 
  lateral 
  extent 
  ; 
  the 
  stem 
  is 
  20 
  millim. 
  in 
  greatest 
  lateral 
  by 
  

   8 
  millim. 
  in 
  greatest 
  antero-posterior 
  diameter. 
  The 
  species 
  has 
  

   much 
  of 
  the 
  external 
  appearance 
  of 
  Spongia 
  carduus, 
  Lamarck, 
  of 
  

   the 
  Paris 
  Museum, 
  the 
  spiculation 
  of 
  which, 
  however, 
  refers 
  it 
  to 
  

   another 
  genus. 
  It 
  difiers 
  from 
  all 
  the 
  species 
  described 
  by 
  Schmidt 
  

   from 
  European 
  and 
  W.-Indian 
  seas 
  in 
  the 
  absence 
  of 
  an 
  acerate 
  

   spicule; 
  in 
  the 
  great 
  stoutness 
  of 
  the 
  main 
  acerate 
  it 
  approaches 
  

   A. 
  mastopliora 
  of 
  that 
  author, 
  from 
  Florida. 
  In 
  general 
  habit 
  it 
  

   resembles 
  Acanthella 
  rather 
  than 
  AxinelJa, 
  but 
  wants 
  the 
  long 
  

   undulating 
  cylindrical 
  spicule 
  hitherto 
  found 
  in 
  species 
  of 
  that 
  

   genus 
  ; 
  it 
  appears 
  doubtful 
  whether 
  the 
  existence 
  of 
  such 
  species 
  

   as 
  this 
  should 
  not 
  induce 
  us 
  to 
  unite 
  the 
  two 
  genera. 
  I 
  have 
  been 
  

   unable 
  to 
  identify 
  it 
  with 
  any 
  described 
  species 
  ; 
  the 
  large 
  stout 
  

   acerate 
  appears 
  to 
  be 
  the 
  most 
  distinctive 
  characteristic. 
  

  

  LEUCOPHLffiUS. 
  

  

  Carter, 
  Ann. 
  8f 
  Mag. 
  N. 
  H. 
  1883, 
  xii. 
  p. 
  323. 
  

  

  In 
  its 
  affinities 
  this 
  genus 
  appears 
  to 
  be 
  Axinellid 
  ; 
  it 
  is 
  dis- 
  

   tinguished 
  from 
  Axinella, 
  s. 
  str., 
  by 
  its 
  loose 
  yielding 
  texture, 
  the 
  

   skeleton- 
  fibres 
  being 
  loosely 
  united, 
  but 
  containing 
  a 
  dense 
  keratose 
  

  

  