﻿SPONGnDA. 
  417 
  

  

  point 
  of 
  attachment 
  ; 
  the 
  length 
  (horizontal) 
  is 
  39 
  millim. 
  (1^ 
  inch), 
  

   greatest 
  (vertical) 
  thickness 
  8 
  millim., 
  average 
  thickness 
  of 
  narrow 
  

   lobe 
  2 
  millim. 
  Colour 
  (in 
  spirit) 
  white 
  ; 
  texture 
  rather 
  firm, 
  harsh 
  

   (Carter 
  says 
  " 
  tender 
  "). 
  A 
  small 
  aperture, 
  about 
  -3 
  millim. 
  in 
  dia- 
  

   meter, 
  at 
  the 
  end 
  of 
  the 
  shorter 
  lobe 
  is 
  the 
  only 
  perceptible 
  vent. 
  

   Surface 
  obscurely 
  wrinkled. 
  Spicules 
  as 
  in 
  yi. 
  panicea^ 
  measuring 
  

   •8 
  to 
  1 
  millim. 
  by 
  -012 
  to 
  -018 
  millim. 
  

  

  This 
  specimen 
  agrees 
  well 
  in 
  size 
  and 
  in 
  its 
  general 
  and 
  spicular 
  

   characters 
  with 
  those 
  described 
  by 
  Mr. 
  Carter 
  from 
  Ceylon. 
  

  

  Hah. 
  Prince 
  of 
  Wales 
  Channel, 
  Torres 
  Straits, 
  5-7 
  fms. 
  

  

  Distribution. 
  Basse 
  Rocks, 
  Ceylon, 
  Kerguelen 
  Island 
  (Carter), 
  

   (Atlantic 
  ?, 
  Carter, 
  I. 
  c). 
  

  

  53. 
  Tedania 
  digitata, 
  varr. 
  

  

  Reniera 
  digitata, 
  Schmidt, 
  Adr. 
  Meer. 
  p. 
  7o, 
  pi. 
  vii. 
  fig. 
  11. 
  

   Reniera 
  ambigua, 
  id. 
  Adr. 
  Meer. 
  Suppl. 
  p. 
  39, 
  pi. 
  iv. 
  fig. 
  8. 
  

   Reuiera 
  muggiana, 
  id. 
  Spontj. 
  Akf. 
  p. 
  28. 
  

   Tedania 
  digitata 
  et 
  muggiaua. 
  Gray, 
  P. 
  Z. 
  S. 
  1867, 
  p. 
  520. 
  

  

  Tedania 
  nigrescens, 
  Schmidt, 
  Adr. 
  Meer. 
  p. 
  74, 
  is 
  probably 
  not 
  

   distinct 
  from 
  the 
  above 
  species 
  ; 
  but, 
  as 
  it 
  was 
  not 
  intelligibly 
  de- 
  

   scribed 
  until 
  after 
  T. 
  digitata, 
  the 
  latter 
  name 
  in 
  any 
  case 
  takes 
  

   precedence. 
  

  

  From 
  a 
  comparison 
  of 
  the 
  specimens 
  and 
  slides 
  of 
  these 
  different 
  

   species 
  in 
  the 
  Museum 
  infer 
  se 
  and 
  with 
  Schmidt's 
  descriptions, 
  I 
  

   come 
  to 
  very 
  much 
  the 
  same 
  conclusion 
  as 
  Schmidt 
  (Atl. 
  Geb. 
  p. 
  43), 
  

   viz. 
  that 
  they 
  are 
  all 
  mere 
  varieties. 
  Schmidt's 
  expression 
  is 
  that 
  

   it 
  is 
  merely 
  a 
  matter 
  of 
  taste 
  whether 
  thej' 
  are 
  called 
  species 
  or 
  

   varieties. 
  The 
  differences 
  in 
  outward 
  form 
  have 
  caused 
  him 
  his 
  

   greatest 
  doubts 
  as 
  to 
  their 
  identity 
  ; 
  and 
  it 
  is 
  true 
  that, 
  while 
  some 
  

   specimens 
  bear 
  large 
  lobate 
  elevations, 
  others 
  are 
  massive, 
  and 
  

   that 
  whereas 
  some 
  have 
  large 
  vents, 
  in 
  others 
  they 
  are 
  all 
  small 
  

   and 
  scattered. 
  But 
  I 
  find 
  that 
  all 
  agree 
  in 
  a 
  more 
  or 
  less 
  massive 
  

   habit, 
  cavernous 
  structure, 
  and 
  strongly 
  ridged 
  or 
  papillose 
  surface; 
  

   whereas 
  the 
  Atlantic 
  form, 
  T. 
  suctoria, 
  Schmidt, 
  and 
  the 
  Chilian 
  

   T. 
  tenuicajntata 
  , 
  mihi, 
  have 
  an 
  almost 
  even 
  surface. 
  

  

  The 
  forms 
  of 
  the 
  spicules 
  are 
  practically 
  the 
  same 
  in 
  all 
  cases, 
  and 
  

   the 
  micro-spination 
  of 
  the 
  heads 
  of 
  the 
  cylindrical 
  " 
  tibiella 
  " 
  is 
  

   undoubted 
  throughout, 
  whereas 
  in 
  the 
  two 
  specified 
  species 
  the 
  heads 
  

   are 
  quite 
  smooth. 
  

  

  The 
  Port-Darwin 
  specimens 
  differ 
  decidedly 
  in 
  the 
  proportions 
  of 
  

   the 
  acuato 
  spicule, 
  as 
  will 
  be 
  seen 
  below, 
  from 
  the 
  rest. 
  None 
  of 
  

   the 
  varieties 
  pointed 
  out 
  seem 
  to 
  stand 
  out 
  with 
  sufficient 
  distinctness 
  

   from 
  the 
  rest 
  to 
  receive 
  distinct 
  varietal 
  names. 
  A 
  specimen 
  lately 
  

   received 
  from 
  Kurrachee 
  agrees 
  essentially 
  with 
  all 
  the 
  above 
  spe- 
  

   cimens, 
  the 
  spicules 
  being 
  only 
  rather 
  stnall 
  ; 
  the 
  surface 
  is 
  broken 
  

   up 
  into 
  a 
  dense 
  mass 
  of 
  slender, 
  almost 
  filiform 
  processes 
  and 
  

   lamellar 
  ridges, 
  from 
  1 
  to 
  5 
  or 
  6 
  millim. 
  high. 
  

  

  