﻿ECHINODKRMATA. 
  143 
  

  

  doubt, 
  will 
  be 
  seen, 
  ■when 
  a 
  large 
  series 
  is 
  to 
  hand, 
  to 
  be 
  nothing 
  

   more 
  than 
  varieties 
  of 
  0. 
  rotata. 
  As 
  none 
  of 
  the 
  arms 
  are 
  complete, 
  

   the 
  measurements 
  I 
  could 
  give 
  might 
  only 
  be 
  deceptive 
  ; 
  in 
  them 
  the 
  

   upper 
  arm-spines 
  are 
  proportionately 
  lai'ger 
  than 
  in 
  the 
  specimen 
  

   already 
  spoken 
  of; 
  the 
  bands 
  separating 
  the 
  plates, 
  the 
  character 
  of 
  

   which 
  has 
  given 
  rise 
  to 
  the 
  specific 
  name, 
  may 
  vary 
  -in 
  breadth 
  on 
  one 
  

   and 
  the 
  same 
  disk; 
  and 
  the 
  granules 
  may 
  be 
  in 
  narrow 
  or 
  broad 
  bands, 
  

   and 
  may 
  be 
  so 
  greatly 
  elongated 
  that 
  they 
  may 
  more 
  correctly 
  be 
  

   spoken 
  of 
  as 
  spines 
  ; 
  the 
  marking 
  would 
  by 
  some 
  be 
  spoken 
  of 
  as 
  

   exceedingly 
  characteristic, 
  for 
  there 
  extend 
  from 
  the 
  disk 
  on 
  to 
  the 
  

   arms 
  two 
  lines 
  of 
  dots 
  of 
  blue 
  ; 
  at 
  every 
  fourth 
  plate, 
  when 
  regular, 
  

   the 
  two 
  dots 
  of 
  either 
  side 
  fuse, 
  and 
  the 
  spot 
  enlarges 
  into 
  a 
  blue 
  

   patch 
  ; 
  an 
  exactly 
  similar 
  marking 
  is 
  to 
  be 
  seen 
  on 
  the 
  lower 
  sur- 
  

   face. 
  In 
  the 
  specimen 
  unhesitatingly 
  placed 
  with 
  0. 
  rotata 
  there 
  is 
  

   not 
  this 
  definite 
  arrangement 
  of 
  the 
  dots. 
  

  

  I 
  have 
  thought 
  it 
  right 
  to 
  direct 
  attention 
  to 
  these 
  peculiarities, 
  

   but 
  a 
  full 
  and 
  satisfactory 
  discussion 
  of 
  the 
  subject 
  must 
  be 
  based 
  

   on 
  a 
  much 
  larger 
  series 
  of 
  specimens. 
  

  

  These 
  examples 
  were 
  also 
  from 
  Thursday 
  Island. 
  

  

  20. 
  Ophiothrix 
  punctolimbata. 
  

   Martens, 
  Arch.f. 
  Nat. 
  1870, 
  p. 
  257. 
  

  

  Port 
  Curtis 
  ; 
  Port 
  Molle 
  ; 
  Thursday 
  Island, 
  3-4 
  fms. 
  ; 
  Prince 
  of 
  

   Wales 
  Channel 
  ; 
  Warrior 
  E-eef. 
  

  

  The 
  specimen 
  from 
  Port 
  Curtis, 
  which 
  is 
  smaller 
  than 
  the 
  others, 
  

   has 
  the 
  lateral 
  spines 
  proportionately 
  longer, 
  more 
  echinulated, 
  and 
  

   much 
  more 
  glossy. 
  

  

  21. 
  Ophiothrix 
  longipeda. 
  

   Lyman, 
  p. 
  35. 
  

  

  Port 
  Curtis 
  ; 
  Port 
  Molle. 
  

  

  22. 
  Ophiothrix 
  microplax. 
  

  

  Disk 
  large, 
  covered 
  with 
  short 
  spines, 
  less 
  thick 
  on 
  the 
  radial 
  

   shields 
  ; 
  ends 
  of 
  the 
  not-thorny 
  arm-spines 
  faintly 
  clavate. 
  Pro- 
  

   portion 
  of 
  arms 
  to 
  disk 
  about 
  6 
  to 
  1. 
  

  

  The 
  disk 
  is 
  rather 
  large 
  (20 
  millim. 
  in 
  diameter) 
  and 
  is 
  covered 
  

   with 
  very 
  short 
  spines, 
  which 
  may 
  almost 
  be 
  described 
  as 
  spinous 
  

   granules 
  ; 
  these 
  are 
  not 
  so 
  closely 
  packed 
  on 
  the 
  radial 
  shields 
  or 
  on 
  

   the 
  actinal 
  surface 
  as 
  on 
  the 
  rest 
  of 
  the 
  disk. 
  The 
  radial 
  shields 
  

   are 
  small, 
  elongated, 
  triangular, 
  the 
  straight 
  base 
  of 
  the 
  one 
  faces 
  

   that 
  of 
  the 
  other 
  ; 
  the 
  plates 
  of 
  each 
  pair 
  are 
  separated 
  by 
  several 
  

   elongated 
  scales, 
  which 
  carry 
  a 
  few 
  longer 
  spines. 
  There 
  is 
  some 
  

   imbrication 
  of 
  the 
  scales 
  on 
  the 
  actinal 
  surface 
  of 
  the 
  disk. 
  

  

  