﻿340 
  COLLECTIONS 
  FROM 
  MELANESIA, 
  

  

  somo 
  small 
  bad 
  specimens 
  ; 
  they 
  are 
  respectively 
  200 
  and 
  220 
  

   millim. 
  (8 
  and 
  9 
  inches) 
  long, 
  extreme 
  lateral 
  extension 
  in 
  the 
  natural 
  

   state 
  probably 
  about 
  70 
  millim. 
  (3 
  inches). 
  This 
  variety 
  is 
  remark- 
  

   able 
  for 
  its 
  varia])ility 
  in 
  external 
  characters, 
  for 
  the 
  great 
  relative 
  

   length 
  of 
  the 
  terminal 
  branches, 
  and 
  the 
  early 
  stage 
  at 
  which 
  branch- 
  

   ing 
  commences, 
  and 
  by 
  the 
  ridged 
  character 
  of 
  the 
  face 
  of 
  the 
  Blatt- 
  

   keule 
  spicule 
  ; 
  in 
  most 
  other 
  respects 
  it 
  closely 
  approaches 
  the 
  

   following 
  variety. 
  

  

  Plexaura 
  prselonga, 
  var. 
  cinerea. 
  (Plate 
  XXXVIII. 
  fig. 
  h.) 
  

  

  Growth 
  upright, 
  in 
  one 
  plane. 
  Stem 
  long. 
  Branching 
  approxi- 
  

   mately 
  dichotomous 
  ; 
  branches 
  few, 
  flexuous 
  : 
  terminal 
  branches 
  100 
  

   to 
  150 
  millim. 
  (4 
  to 
  6 
  inches) 
  long 
  ; 
  stem 
  and 
  branches 
  cylindrical, 
  

   approximately 
  of 
  one 
  diameter, 
  viz. 
  aboiit 
  2*3 
  millim., 
  throughout. 
  

   Cortex 
  minutely 
  rough, 
  even, 
  fairly 
  tenacious. 
  Colour 
  in 
  dry 
  

   state 
  dark 
  dirty 
  grey. 
  Verrucoe 
  small, 
  slightly 
  projecting 
  from 
  the 
  

   surface 
  as 
  low 
  mounds, 
  their 
  openings 
  extended 
  in 
  direction 
  of 
  length 
  

   of 
  branch; 
  about 
  1 
  millim. 
  distant 
  from 
  each 
  other, 
  equally 
  distri- 
  

   buted 
  all 
  over 
  cortex. 
  Axis 
  tough, 
  flexible, 
  glossy 
  dark 
  brown. 
  

   Cortical 
  spicules 
  : 
  — 
  (i.) 
  Long 
  fnsiform, 
  approximately 
  straight, 
  

   tapering 
  to 
  sharp 
  points, 
  with 
  scattered, 
  tapering, 
  sharp, 
  simple 
  

   tubercles 
  ; 
  size 
  -21 
  to 
  -35 
  by 
  -07 
  millim. 
  (ii.) 
  Stout 
  fusiform-cylin- 
  

   drical, 
  curved, 
  rather 
  thickly 
  covered 
  with 
  low 
  compound 
  tubercles, 
  

   often 
  extended 
  in 
  direction 
  of 
  circumference 
  of 
  spicule, 
  with 
  pointed 
  

   ends 
  ; 
  size 
  about 
  -3 
  by 
  -12 
  miUim. 
  (iii.) 
  Irregular 
  tri- 
  to 
  sex- 
  

   radiate, 
  the 
  arms 
  cylindrical, 
  blunt, 
  covered 
  with 
  few 
  and 
  scattered, 
  

   mostly 
  low 
  and 
  blunt 
  tubercles 
  ; 
  maximum 
  diameter 
  of 
  spicule 
  

   •18 
  to 
  -21 
  millim., 
  thickness 
  of 
  arms 
  -042 
  to 
  -053 
  millim. 
  (iv.) 
  

   Blattkeule, 
  extremely 
  variable, 
  in 
  form 
  ; 
  shaft 
  provided 
  with 
  very 
  

   stout 
  neck, 
  generally 
  branching 
  into 
  two 
  (occasionally 
  three) 
  stout 
  

   arms 
  ; 
  the 
  latter 
  are 
  well 
  covered 
  with 
  compound, 
  rather 
  angular 
  

   tubercles, 
  the 
  neck 
  and 
  proximal 
  part 
  of 
  foliar 
  portion 
  bearing 
  

   broader, 
  more 
  fungiform 
  tubercles 
  ; 
  the 
  foliar 
  portion 
  is 
  flattened 
  

   in 
  one 
  plane, 
  and 
  either 
  transversely 
  oblong 
  with 
  four 
  rounded 
  

   angles, 
  or 
  cordate 
  with 
  sharp 
  lancet-like 
  extremity, 
  or 
  with 
  the 
  

   lower 
  extremity 
  prolonged 
  into 
  several 
  long 
  teeth 
  ; 
  the 
  edges 
  are 
  

   thin 
  and 
  always 
  more 
  or 
  less 
  dentate, 
  at 
  any 
  rate 
  at 
  the 
  outer 
  

   extremity, 
  with 
  small 
  teeth 
  ; 
  the 
  proximal 
  part 
  of 
  the 
  face 
  carries, 
  

   as 
  already 
  mentioned, 
  a 
  few 
  large, 
  fungoid, 
  compound 
  tubercles 
  ; 
  

   one 
  variety 
  which 
  has 
  the 
  edges 
  much 
  dentate 
  has 
  also 
  a 
  number 
  

   of 
  small 
  tubercles 
  extended 
  almost 
  as 
  far 
  outwards 
  as 
  the 
  edges. 
  

   Size 
  of 
  spicule 
  about 
  -35 
  long 
  by 
  -35 
  millim. 
  broad. 
  

  

  Ilab. 
  Port 
  Curtis, 
  Queensland, 
  5-10 
  fms. 
  ; 
  bottom 
  sand 
  and 
  

   shells. 
  

  

  This 
  variety 
  is 
  represented 
  by 
  a 
  single 
  dry 
  specimen, 
  measuring 
  

   230 
  and 
  180 
  millim. 
  (9 
  and 
  7 
  inches) 
  in 
  extreme 
  height 
  and 
  diameter 
  

   respectively. 
  It 
  differs 
  from 
  var. 
  tyj^ica 
  chiefly 
  in 
  the 
  tubercnlate 
  

   rather 
  than 
  ridged 
  character 
  of 
  the 
  faces 
  of 
  the 
  "Blatt" 
  of 
  the 
  

   Blattkeule 
  spicule. 
  

  

  