﻿418 
  

  

  COLLECTIONS 
  FROM 
  MELANESIA 
  . 
  

  

  I 
  append 
  a 
  Table 
  showing 
  the 
  chief 
  variations 
  in 
  the 
  proportions 
  

   of 
  the 
  spicules 
  : 
  — 
  

  

  Proportions 
  of 
  Spicules 
  (in 
  millim.). 
  

  

  In 
  the 
  present 
  collection 
  are 
  some 
  more 
  or 
  less 
  fragmentary 
  

   specimens, 
  and 
  two 
  which 
  incrust 
  crabs, 
  all 
  well 
  preserved 
  in 
  spirit; 
  

   they 
  are 
  either 
  broad, 
  massive, 
  about 
  '2b 
  millim. 
  (1 
  inch) 
  thick, 
  or 
  in- 
  

   crusting, 
  1 
  to 
  about 
  6 
  millim. 
  thick. 
  The 
  surface 
  is 
  covered 
  with 
  more 
  

   or 
  less 
  closely-set 
  ridges 
  or 
  monticular 
  elevations, 
  from 
  1 
  to 
  3 
  millim. 
  

   high. 
  The 
  colour 
  is 
  pale 
  grey 
  of 
  difterent 
  shades 
  (a 
  purple 
  colour 
  

   in 
  one 
  case 
  being 
  apparently 
  derived 
  from 
  a 
  purple 
  sponge 
  which 
  

   arrived 
  in 
  the 
  same 
  bottle 
  of 
  spirit). 
  The 
  spicules 
  agree 
  closely 
  in 
  

   form 
  with 
  those 
  of 
  Mediterranean 
  specimens 
  ; 
  and 
  the 
  only 
  notable 
  

   difference 
  iu 
  proportion 
  is 
  that 
  the 
  diameter 
  of 
  the 
  acuate 
  is 
  from 
  

   ^ 
  to 
  I 
  less 
  than 
  that 
  of 
  those 
  specimens. 
  The 
  colour 
  is 
  paler 
  thaa 
  

   in 
  the 
  Mediterranean 
  forms 
  ; 
  but 
  these 
  exhibit 
  a 
  wider 
  range 
  of 
  

   variation 
  in 
  this 
  respect 
  than 
  is 
  shown 
  by 
  a 
  comparison 
  of 
  the 
  

   darkest 
  Australian 
  and 
  palest 
  Mediterranean 
  specimen. 
  Therefore 
  

   I 
  feel 
  fully 
  justified 
  in 
  uniting 
  the 
  two 
  groups 
  of 
  forms 
  as 
  one 
  

   species, 
  remarkable 
  for 
  its 
  wide 
  geographical 
  distribution, 
  poly- 
  

   morphic 
  external 
  habit, 
  and 
  great 
  range 
  of 
  spicular 
  variation. 
  

  

  Hah. 
  Alert 
  and 
  Thursday 
  Islands, 
  and 
  Prince 
  of 
  Wales 
  Channel, 
  

   Torres 
  Straits, 
  3-9 
  fms. 
  ; 
  Port 
  Darwin, 
  between 
  tide-marks. 
  

  

  Bisirihuiion. 
  Mediterranean 
  {Schmidt) 
  ; 
  Atlantic 
  (Schmidt) 
  ; 
  

   Antigua 
  (Carter); 
  Kurrachee 
  (coll. 
  Brit. 
  Mus.). 
  

  

  T. 
  incrcsceas, 
  Schmidt, 
  JB. 
  Comm. 
  Unters. 
  deutsch. 
  Meer. 
  ii.-iii. 
  

   p. 
  ] 
  15 
  (off 
  tS.W. 
  Norway), 
  differs 
  from 
  these 
  and 
  all 
  described 
  

   species 
  in 
  having 
  a 
  spinulate 
  head 
  to 
  most 
  of 
  the 
  smooth 
  acuates. 
  

  

  