﻿610 
  COLLECTIONS 
  FROM 
  THE 
  WESTERN 
  INDIAN 
  OCEAN. 
  

  

  Sarcode-spicules 
  : 
  — 
  (3) 
  Tricurvate 
  acerate, 
  smooth, 
  tapering 
  gra- 
  

   dually 
  to 
  fine 
  points 
  ; 
  median 
  curve 
  rather 
  sharp, 
  forming 
  angle 
  

   of 
  about 
  150° 
  ; 
  from 
  this 
  point 
  arms 
  almost 
  straight, 
  until 
  just 
  

   before 
  tips, 
  which 
  turn 
  up 
  slightly 
  ; 
  size 
  •19--22 
  by 
  '006 
  millim. 
  

   (4) 
  Equianchorate, 
  navicular, 
  shaft 
  slender, 
  smooth, 
  curve 
  gradual 
  

   and 
  slight 
  ; 
  palms 
  narrow, 
  viz, 
  about 
  '08 
  long 
  by 
  '0055 
  millim. 
  broad, 
  

   tapering 
  to 
  sharp 
  points 
  at 
  apex, 
  square 
  below 
  ; 
  tubercle 
  slight, 
  

   rather 
  elongate, 
  length 
  -022 
  millim. 
  

  

  Hah. 
  Mozambique, 
  between 
  tide-marks. 
  

  

  Two 
  specimens 
  and 
  a 
  fragment 
  are 
  in 
  the 
  coUeetion. 
  The 
  largest 
  

   measures 
  110 
  millim. 
  (4^ 
  inches) 
  in 
  greatest 
  height, 
  85 
  millim. 
  

   (3^ 
  inches) 
  in 
  greatest 
  lateral 
  expansion 
  ; 
  common 
  stem 
  55 
  millim. 
  

   long, 
  20 
  by 
  10 
  millim. 
  in 
  diameter 
  at 
  middle 
  of 
  its 
  course, 
  rather 
  

   tortuous, 
  deeply 
  scored 
  on 
  one 
  side 
  by 
  a 
  main 
  median 
  longitudinal 
  

   depression. 
  The 
  second 
  specimen 
  has 
  its 
  branches 
  more 
  cylindrical 
  

   than 
  those 
  of 
  the 
  larger 
  specimen 
  : 
  but 
  it 
  has 
  grown 
  abnormally, 
  some 
  

   of 
  the 
  branches 
  being 
  twisted 
  back, 
  and 
  anastomosis 
  occurs 
  near 
  the 
  

   base 
  of 
  the 
  specimen. 
  The 
  description 
  of 
  Sponrjia 
  palmata, 
  Lamarck 
  

   (Ann. 
  Mus. 
  Hist. 
  Nat. 
  xx. 
  p. 
  453), 
  var. 
  /3, 
  recalls 
  this 
  sponge. 
  The 
  

   typical 
  form 
  of 
  the 
  species, 
  which 
  I 
  have 
  seen 
  at 
  Paris, 
  resembles 
  it 
  

   more 
  closely 
  than 
  does 
  the 
  specimen 
  on 
  which 
  this 
  var. 
  /3 
  was 
  pro- 
  

   bably 
  founded 
  ; 
  however, 
  microscopic 
  examination 
  shows 
  S. 
  ])ahnata 
  

   to 
  be 
  a 
  Chalina. 
  While 
  the 
  present 
  species 
  resembles 
  Desmacidon 
  

   fruticosa, 
  Mont., 
  in 
  texture 
  and 
  in 
  the 
  structure 
  of 
  the 
  skeleton, 
  it 
  

   is 
  yet 
  quite 
  distinct 
  on 
  account 
  of 
  its 
  solid 
  branches, 
  its 
  acerate 
  

   skeleton- 
  and 
  its 
  tricurvate 
  (not 
  bihamate) 
  flesh-spicules. 
  D.arci- 
  

   ferum, 
  Schmidt 
  (Algiers), 
  appears 
  to 
  approach 
  it 
  the 
  most 
  nearly 
  of 
  

   described 
  species, 
  but 
  an 
  acerate 
  spicule 
  is 
  mentioned 
  in 
  addition 
  to 
  

   the 
  tricurvate. 
  D. 
  frondosum 
  (Ehlers), 
  Esper, 
  from 
  " 
  East 
  Indies," 
  

   resembles 
  this 
  sponge 
  in 
  general 
  appearance, 
  but 
  has 
  echinating 
  

   spicules, 
  some 
  of 
  which 
  are 
  strongly 
  spined, 
  and 
  no 
  tricurvate 
  is 
  

   mentioned 
  ; 
  hence 
  it 
  seems 
  to 
  be 
  a 
  Clatliria. 
  

  

  31. 
  lotrochota 
  purpurea. 
  

  

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

  

  See 
  Part 
  I., 
  p. 
  434, 
  of 
  this 
  Report. 
  

  

  Fine 
  specimens, 
  chiefly 
  of 
  the 
  usual 
  cylindrical 
  form, 
  and 
  with 
  

   the 
  same 
  coarsely 
  roughened 
  surface 
  as 
  in 
  the 
  Australian 
  specimens. 
  

   Like 
  those 
  specimens, 
  too, 
  they 
  show 
  a 
  tendency 
  to 
  become 
  flattened, 
  

   and 
  to 
  vary 
  in 
  colour 
  from 
  dark 
  purple 
  to 
  dark 
  green. 
  The 
  spicu- 
  

   lation 
  is 
  essentially 
  the 
  same 
  as 
  in 
  the 
  Australian 
  specimens. 
  The 
  

   maximum 
  height 
  is 
  also 
  just 
  the 
  same, 
  viz. 
  150 
  millim. 
  (6 
  inches). 
  

  

  Hah. 
  Etoile 
  Island, 
  Amirante 
  group, 
  13 
  fms. 
  

  

  Distribution. 
  See 
  Part 
  I. 
  p. 
  434. 
  

  

  32. 
  lotrochota 
  baculifera. 
  

  

  See 
  Part 
  I., 
  p. 
  435, 
  of 
  this 
  Report. 
  

  

  Some 
  smaU 
  specimens, 
  in 
  spirit 
  and 
  in 
  the 
  dry 
  state. 
  In 
  the 
  

  

  