﻿434 
  COLLECTIONS 
  FROM 
  MELANESIA. 
  

  

  primary 
  skeleton- 
  fibres 
  ; 
  the 
  canals 
  I 
  have 
  mentioned 
  range 
  in 
  dia- 
  

   meter 
  from 
  about 
  •07 
  to 
  -14 
  millim. 
  This 
  opening 
  of 
  a 
  considerable 
  

   proportion 
  of 
  the 
  ciliated 
  chambers 
  directly 
  into 
  moderately 
  wide 
  

   canals 
  agrees 
  with 
  what 
  Vosmaer 
  finds 
  to 
  be 
  the 
  arrangement 
  in 
  

   many 
  forms 
  of 
  the 
  other 
  Mouactinellid 
  families 
  Ileuierida3 
  and 
  Sub- 
  

   eritidte, 
  as 
  well 
  as 
  in 
  a 
  few 
  other 
  forms, 
  viz. 
  his 
  third 
  type 
  (' 
  Antee- 
  

   keningen 
  over 
  Leucandra 
  aspcra, 
  H.,' 
  Leyden, 
  1880, 
  and 
  Tijdscbrift 
  

   Nederl. 
  Dierk. 
  Vereen. 
  v. 
  p. 
  144 
  et 
  seq.). 
  

  

  67. 
  lotrochota 
  purpurea. 
  

   (Plate 
  XXXIX. 
  fig. 
  L 
  ; 
  Plate 
  XLII. 
  figs, 
  e-e"".) 
  

  

  Halichondria 
  purpurea, 
  Boiverbank, 
  P. 
  Z. 
  S. 
  1875, 
  p. 
  293. 
  

  

  Dr. 
  Bowerbank's 
  specimen 
  (from 
  the 
  Straits 
  of 
  Malacca) 
  is 
  evi- 
  

   dently 
  quite 
  young 
  ; 
  the 
  present 
  fine 
  series 
  of 
  specimens, 
  both 
  dry 
  

   and 
  in 
  spirit 
  (numbering 
  upwards 
  of 
  twenty), 
  gives 
  a 
  better 
  idea 
  of 
  

   the 
  charactei's 
  of 
  the 
  species. 
  

  

  The 
  external 
  form 
  is 
  usually 
  that 
  of 
  a 
  cylindrical 
  column, 
  narrow, 
  

   diminishing 
  gradually 
  in 
  thickness 
  towards 
  apex, 
  viz. 
  from 
  about 
  15 
  

   millim. 
  at 
  base 
  to 
  4 
  millim. 
  at 
  apex 
  in 
  adult 
  specimens, 
  dividing 
  

   towards 
  the 
  apex 
  into 
  two 
  or 
  three 
  subequal 
  branches 
  ; 
  it 
  is 
  some- 
  

   times 
  flattened 
  irregularly 
  near 
  the 
  base 
  ; 
  it 
  occasionally 
  forms 
  a 
  

   broad 
  palmate 
  frond 
  or 
  irregular 
  erect 
  expansion, 
  or 
  an 
  irregularly 
  

   honeycombed 
  horizontal 
  mass 
  which 
  may 
  attain 
  a 
  diameter 
  of 
  65 
  

   millim. 
  (2| 
  inches). 
  The 
  surface 
  is 
  broken 
  up 
  into 
  a 
  forest 
  of 
  

   pointed 
  or 
  ridge-like 
  monticular 
  elevations, 
  1-3 
  millim. 
  apart, 
  1-3 
  

   millim. 
  high. 
  In 
  the 
  typical 
  specimen 
  (dry) 
  the 
  surface 
  aculeations 
  

   are 
  only 
  -5 
  to 
  1 
  millim. 
  apart 
  and 
  the 
  same 
  in 
  height. 
  Texture 
  in 
  

   spirit 
  rather 
  firm, 
  but 
  soft 
  on 
  surface, 
  tough 
  and 
  flexible 
  ; 
  in 
  dry 
  

   state 
  harsh 
  on 
  surface, 
  rather 
  brittle 
  : 
  colour 
  in 
  spirit 
  very 
  deep 
  

   purple, 
  in 
  drj- 
  state 
  dark 
  green 
  or 
  pale 
  purple. 
  8kcleton 
  rectangular, 
  

   consisting 
  of 
  stout 
  compact 
  primary 
  spiculo-fibres 
  devoid 
  of 
  visible 
  

   horny 
  material, 
  10 
  to 
  iiO 
  spicules 
  broad, 
  and 
  of 
  similar 
  secondary 
  

   fibres 
  1 
  to 
  3 
  spicules 
  broad. 
  Skeleton 
  -spicules 
  smooth, 
  acuate, 
  

   rather 
  squarely 
  rounded 
  at 
  base, 
  tapering 
  to 
  a 
  sharp 
  point 
  from 
  about 
  

   five 
  diameters 
  from 
  end; 
  size 
  chiefly 
  -26 
  by 
  -0063 
  millim., 
  a 
  few 
  

   in 
  the 
  interior 
  of 
  the 
  primary 
  fibres 
  '18 
  by 
  -005 
  to 
  -OOi'o 
  millim. 
  (in 
  

   the 
  type 
  the 
  prevailing 
  size 
  is 
  '16 
  by 
  •0127 
  millim. 
  and 
  the 
  spicule 
  

   frequently 
  increases 
  in 
  diameter 
  from 
  the 
  base 
  towards 
  the 
  centre). 
  

   Flesh-spicule 
  birotulate 
  (not 
  eqnianchorate, 
  as 
  stated 
  by 
  Bowerbank), 
  

   shatt 
  verj' 
  slender 
  ; 
  rotulse 
  small, 
  umbrella-shaped, 
  with 
  four 
  equal 
  

   curved 
  teeth 
  ; 
  length 
  of 
  spicule 
  "016 
  to 
  ^019 
  millim. 
  Sarcode 
  in 
  

   spirit 
  dark 
  purple, 
  granular 
  ; 
  in 
  dry 
  state 
  either 
  dark 
  purple 
  or 
  dark 
  

   greenish. 
  Large 
  specimens 
  attain 
  a 
  height 
  of 
  about 
  150 
  millim. 
  

   (6 
  inches). 
  

  

  Hab. 
  Torres 
  Straits, 
  various 
  localities 
  down 
  to 
  10 
  fms, 
  ; 
  Albany 
  

   Island, 
  3-4 
  fms. 
  ; 
  Port 
  Molle, 
  coral-reef. 
  

  

  DistrUnitlon. 
  Straits 
  of 
  Malacca 
  (Bowerbank). 
  

  

  The 
  specimens 
  referred 
  to 
  as 
  being 
  greenish 
  in 
  colour 
  are 
  all 
  dry. 
  

  

  