﻿SPONGHDA. 
  583 
  

  

  representing 
  the 
  African 
  coast) 
  ; 
  2. 
  Glorioso 
  Islands 
  (as 
  the 
  most 
  

   southern 
  investigated 
  member 
  of 
  the 
  outlying 
  groups 
  of 
  islands 
  ; 
  

   3. 
  Providence 
  Island 
  and 
  lleef, 
  still 
  further 
  north 
  ; 
  4. 
  Amirante 
  

   Islands, 
  a 
  further 
  northward 
  step 
  in 
  the 
  direction 
  of 
  (5) 
  the 
  

   Sej'chelles. 
  

  

  The 
  physical 
  relations 
  of 
  these 
  different 
  localities 
  and 
  their 
  coasts 
  

   are 
  ably 
  described 
  in 
  Dr. 
  Coppinger's 
  ' 
  Cruise 
  of 
  the 
  Alert 
  '; 
  I 
  have 
  

   added 
  to 
  my 
  descriptions 
  of 
  the 
  species 
  notes 
  as 
  to 
  localities 
  and 
  

   nature 
  of 
  bottom, 
  taken 
  from 
  his 
  own 
  notes 
  accompanying 
  the 
  

   specimens. 
  

  

  Depth. 
  — 
  It 
  will 
  be 
  seen 
  that 
  the 
  depths 
  investigated 
  did 
  not 
  

   exceed 
  24 
  fms. 
  

  

  Localltij 
  .—Ahoni 
  half 
  the 
  gatherings 
  are 
  from 
  a 
  bottom 
  composed 
  

   either 
  of 
  sand, 
  sand 
  and 
  coral, 
  or 
  broken 
  coral 
  ; 
  in 
  but 
  two 
  cases 
  (in 
  the 
  

   Amirante 
  Islands) 
  is 
  mud 
  recorded 
  ; 
  the 
  remaining 
  localities 
  are 
  given 
  

   either 
  " 
  beach," 
  reef, 
  or 
  " 
  between 
  tide-marks." 
  I 
  know 
  of 
  no 
  previous 
  

   descriptions 
  of 
  Sponges 
  from 
  Mozambicjue 
  or 
  any 
  part 
  of 
  the 
  Eastern 
  

   coast 
  of 
  Africa 
  nearer 
  than 
  Zanzibar, 
  whence 
  A. 
  Hyatt* 
  derived 
  many 
  

   of 
  theCeratose 
  species 
  referred 
  to 
  in 
  his 
  paper 
  "He 
  vision 
  of 
  the 
  North- 
  

   American 
  Poriferaj 
  " 
  &c. 
  Prof. 
  E. 
  P. 
  Wright 
  has 
  introduced 
  us 
  to 
  

   the 
  Sponges 
  of 
  the 
  Seychelle 
  Islands 
  in 
  a 
  paper 
  t 
  on 
  Alemo 
  seycJiel- 
  

   lensis, 
  collected 
  with 
  many 
  other 
  species 
  by 
  himself 
  many 
  years 
  since. 
  

   The 
  Glorioso 
  and 
  Amirante 
  Islands 
  and 
  Providence 
  Reef 
  and 
  Island 
  

   are 
  entirely 
  new 
  ground 
  in 
  this 
  respect. 
  Practically 
  the 
  only 
  ac- 
  

   quaintance 
  we 
  have 
  hitherto 
  had 
  with 
  the 
  Sponge-fauna 
  of 
  this 
  

   Western 
  part 
  of 
  the 
  Indian 
  Ocean 
  is 
  derived 
  from 
  papers 
  by 
  Mr. 
  Carter 
  

   describing 
  a 
  few 
  Silicea 
  from 
  Mauritius 
  (especially 
  in 
  Ann. 
  & 
  jMag. 
  

   Nat. 
  Hist. 
  1879, 
  iii. 
  p. 
  284, 
  five 
  species), 
  and 
  one 
  by 
  Schuffner 
  

   (' 
  Jenaische 
  Zeitschrift,' 
  xi. 
  p. 
  403, 
  pis. 
  xxiv.-xxvi.) 
  describing 
  (5 
  new 
  

   Calcarea 
  from 
  Mcibius's 
  collections 
  at 
  Mauritius. 
  Thus 
  it 
  may 
  justly 
  

   be 
  claimed 
  that 
  in 
  magnitude 
  and 
  interest 
  the 
  present 
  collection 
  far 
  

   excels 
  any 
  collection 
  hitherto 
  described 
  from 
  these 
  waters. 
  

  

  Looking 
  generally 
  at 
  the 
  distribution 
  of 
  the 
  fifty-six 
  species 
  here 
  

   described 
  (see 
  Table 
  of 
  Distribution, 
  p. 
  586), 
  and 
  comparing 
  it 
  with 
  

   that 
  of 
  the 
  species 
  obtained 
  at 
  or 
  near 
  the 
  eastern 
  confines 
  of 
  the 
  

   same 
  Ocean 
  (this 
  Report, 
  Part 
  I. 
  p. 
  372), 
  we 
  find 
  a 
  similar 
  resem- 
  

   blance 
  to 
  the 
  Atlantic 
  fauna 
  (including 
  the 
  Mediterranean) 
  in 
  both 
  

   areas 
  : 
  excluding 
  doubtful 
  cases 
  we 
  have 
  here 
  7 
  out 
  of 
  55 
  species 
  as 
  

   against 
  12 
  out 
  of 
  106 
  species 
  decidedly 
  identical 
  with 
  Atlantic 
  forms. 
  

   We 
  have 
  the 
  same 
  number 
  (3) 
  of 
  species 
  recorded 
  also 
  from 
  Ceylon. 
  

   Some 
  species 
  (lotrochota 
  purpurea, 
  Clafhria 
  frondifera) 
  range 
  to 
  the 
  

   Straits 
  of 
  Malacca, 
  and 
  hence, 
  as 
  we 
  have 
  seen 
  above 
  (p. 
  371), 
  to 
  

   Australia; 
  two 
  extend 
  across 
  into 
  mid-Pacific 
  (Carterisjioiu/ia 
  

   otahitica, 
  StelJetta 
  acervus). 
  The 
  almost 
  cosmopolitan 
  Australian 
  

   species 
  Leucetta 
  primvjenia 
  and 
  Tedania 
  digitata 
  are 
  found 
  hero 
  

   also. 
  

  

  Passing 
  to 
  the 
  more 
  direct 
  relations 
  of 
  the 
  Australian 
  and 
  Western 
  

  

  * 
  Mem. 
  Bost. 
  Soc. 
  ii. 
  pt. 
  4, 
  nos. 
  ii. 
  & 
  v. 
  

  

  t 
  Proc. 
  R. 
  Irish 
  Academy, 
  xxviii. 
  p. 
  13, 
  pi. 
  i. 
  

  

  