﻿ECniNODEEMATA. 
  149 
  

  

  belong 
  to 
  an 
  outer, 
  and 
  at 
  others 
  to 
  an 
  inner 
  circle 
  on 
  the 
  disk 
  ; 
  and 
  

   that 
  the 
  colour 
  which 
  in 
  some 
  cases 
  is 
  light 
  brown, 
  in 
  others 
  is 
  

   purplish 
  grey. 
  

  

  Albanj' 
  Island; 
  Torres 
  Straits. 
  

  

  Quite 
  recently 
  an 
  example 
  of 
  this 
  species 
  has 
  been 
  receiv^ed 
  from 
  

   Kurrachee. 
  

  

  8. 
  Thyone 
  mirabilis 
  (?) 
  . 
  

   Thyone 
  mirabilis, 
  Ludwig, 
  Semper 
  s 
  Arbeiten, 
  ii. 
  p. 
  93. 
  

  

  The 
  form 
  of 
  the 
  spicules 
  would 
  perhaps 
  allow 
  us 
  to 
  place 
  the 
  

   single 
  specimen 
  hero 
  with 
  doubt 
  referred 
  to 
  this 
  species 
  either 
  with 
  

   it 
  or 
  with 
  llolotliuria 
  dletricliii 
  of 
  Ludwig, 
  the 
  supporting-rods 
  in 
  

   the 
  suckers 
  of 
  the 
  latter 
  not 
  being 
  figured. 
  Though 
  our 
  specimen 
  

   has 
  much 
  more 
  the 
  form 
  and 
  colour, 
  so 
  far 
  as 
  one 
  may 
  judge 
  from 
  

   the 
  description, 
  of 
  the 
  Holothurian, 
  the 
  eight 
  large 
  arborescent 
  and 
  

   two 
  small 
  tentacles, 
  the 
  scattered 
  sucker-feet, 
  and 
  the 
  unarmed 
  

   anal 
  orific 
  exactly 
  determine 
  its 
  generic 
  affinities. 
  

  

  Port 
  Denison. 
  

  

  9. 
  Thyone 
  sacellus 
  *. 
  

  

  Stolus 
  sacellus, 
  Selenka, 
  Zeit. 
  f. 
  iviss. 
  Zool. 
  xvii. 
  p. 
  355. 
  

  

  Thyone 
  rigida, 
  Semper, 
  Holothuvien, 
  p. 
  66. 
  

  

  Thyone 
  sacella, 
  von 
  Marenzeller, 
  Verh, 
  z.-bot. 
  Ges. 
  Wien, 
  1881, 
  p. 
  131. 
  

  

  Torres 
  Straits. 
  

  

  10. 
  Thyone 
  okeni. 
  (Plate 
  IX. 
  fig. 
  D.) 
  

  

  The 
  two 
  specimens 
  of 
  this 
  species 
  are 
  in 
  remarkably 
  good 
  condi- 
  

   tion 
  for 
  examination, 
  as 
  one 
  died 
  with 
  its 
  tentacles 
  fully 
  expanded 
  

   and 
  the 
  other 
  was 
  laid 
  open 
  by 
  the 
  collector. 
  

  

  With 
  the 
  exception 
  of 
  the 
  terminal 
  plate 
  in 
  the 
  suckers 
  I 
  have 
  

   not 
  been 
  able 
  to 
  detect 
  any 
  calcareous 
  bodies 
  either 
  in 
  the 
  suckers 
  

   or 
  the 
  integument 
  ; 
  and 
  if 
  any 
  such 
  are 
  present 
  they 
  must 
  be 
  ex- 
  

   ceedingly 
  small 
  and 
  very 
  rare. 
  This 
  characteristic 
  brings 
  this 
  

   species 
  into 
  proximity 
  to 
  the 
  T. 
  villosa 
  of 
  Semper, 
  where, 
  as 
  in 
  this, 
  

   the 
  suckers 
  are 
  very 
  closely 
  packed. 
  

  

  Elongated 
  in 
  form, 
  very 
  dark 
  brown 
  in 
  colour 
  (in 
  spirit), 
  tentacles 
  

   of 
  about 
  the 
  same 
  shade 
  ; 
  suckers 
  closely 
  packed 
  and 
  distributed 
  over 
  

   the 
  whole 
  body, 
  their 
  radial 
  arrangement 
  in 
  the 
  region 
  of 
  the 
  anus 
  

   very 
  obscurely 
  indicated. 
  Anus 
  without 
  teeth. 
  Retractors 
  inserted 
  

   very 
  nearly 
  as 
  far 
  back 
  as 
  the 
  middle 
  of 
  the 
  body. 
  Calcareous 
  ring 
  

   of 
  ten 
  pieces, 
  the 
  radial 
  similar 
  to 
  the 
  interradial, 
  elongated, 
  and 
  

   wider 
  below 
  than 
  above 
  (fig. 
  I)). 
  Calcareous 
  plating 
  extends 
  some 
  

   way 
  along 
  the 
  enteric 
  tract 
  (fig. 
  D). 
  Genital 
  tubes 
  numerous, 
  very 
  

   slender 
  and 
  long, 
  inserted 
  behind 
  the 
  middle 
  point 
  of 
  tlie 
  length 
  of 
  

  

  * 
  Prof. 
  Selenka 
  has 
  been 
  kind 
  enough 
  to 
  inform 
  me 
  that 
  sacellus, 
  as 
  used 
  

   by 
  him, 
  is 
  a 
  diminutive 
  form 
  of 
  saccus, 
  not 
  of 
  sacer. 
  

  

  