﻿ECHINODERMATA, 
  169 
  

  

  24. 
  Actinometra 
  alternans. 
  

   P. 
  H. 
  Carpenter, 
  Notes 
  Leyd. 
  Mus. 
  iii. 
  p. 
  208. 
  

  

  An 
  example 
  of 
  this 
  interesting 
  species 
  was 
  determined 
  for 
  me 
  by 
  

   Mr. 
  P. 
  H. 
  Carpenter 
  ; 
  the 
  stumps 
  of 
  two 
  cirri 
  are 
  still 
  present. 
  

   Port 
  Molle. 
  

  

  25. 
  Actinometra 
  paucicirra. 
  (Plate 
  XYII. 
  fig. 
  A, 
  a.) 
  

  

  Centrodorsal 
  small, 
  low, 
  rounded, 
  with 
  5 
  or 
  6 
  marginal 
  cirri 
  of 
  

   15-18 
  joints, 
  a 
  number 
  of 
  which 
  are 
  longer 
  than 
  broad 
  ; 
  the 
  penul- 
  

   timate 
  spine 
  exceedingly 
  small. 
  

  

  First 
  radials 
  visible, 
  second 
  radials 
  very 
  wide, 
  not 
  in 
  contact, 
  

   united 
  with 
  the 
  third 
  by 
  a 
  syzygy. 
  Twenty 
  arms 
  ; 
  two 
  joints 
  in 
  the 
  

   distichals 
  united 
  by 
  a 
  syzygy, 
  the 
  more 
  prominent 
  joints 
  in 
  contact. 
  

   First 
  and 
  second 
  brachials 
  united 
  by 
  a 
  syzygy 
  ; 
  third 
  and 
  fourth 
  

   pretty 
  regularly 
  obloHg 
  ; 
  the 
  fifth 
  faintly 
  wedge-shaped 
  ; 
  after 
  this 
  

   the 
  wedge-shaped 
  form 
  becomes 
  more 
  marked, 
  but 
  the 
  edges 
  do 
  not 
  

   overlap. 
  

  

  Syzygies 
  on 
  the 
  eighth 
  and 
  twelfth, 
  then 
  from 
  3-5 
  joints 
  between 
  

   each. 
  First 
  pinnules 
  longer 
  than 
  the 
  second, 
  and 
  the 
  tliird 
  than 
  the 
  

   fourth; 
  the 
  first 
  alone 
  of 
  any 
  considerable 
  size 
  : 
  its 
  joints 
  ])roduccd 
  

   into 
  very 
  prominent 
  edges. 
  The 
  succeeding 
  pinnules 
  small; 
  later 
  

   out 
  they 
  enlarge 
  somewhat, 
  but 
  are 
  never 
  at 
  all 
  long. 
  

  

  Arms 
  about 
  70 
  millim. 
  long, 
  cirri 
  8 
  millim., 
  disk 
  7 
  millim. 
  in 
  

   diameter. 
  A 
  slight 
  development 
  of 
  calcareous 
  deposit 
  between 
  the 
  

   bases 
  of 
  the 
  arms. 
  

  

  Colour 
  creamy 
  white 
  above, 
  rather 
  darker 
  below. 
  

  

  Prince 
  of 
  Wales 
  Channel 
  ; 
  Thursday 
  Island. 
  

  

  26. 
  Actinometra 
  multifida. 
  

  

  Comatula 
  multifida, 
  /. 
  Miill. 
  p. 
  26. 
  

  

  Percy 
  Island, 
  Queensland; 
  Albany 
  Island; 
  Prince 
  of 
  Wales 
  

   Channel. 
  

  

  27. 
  Actinometra 
  variabilis. 
  (Plate 
  XVII. 
  fig. 
  B, 
  a.) 
  

  

  Centrodorsal 
  of 
  moderate 
  size, 
  concave 
  in 
  the 
  middle, 
  with 
  10 
  

   marginal 
  cirri, 
  of 
  about 
  15 
  joints 
  ; 
  very 
  faint 
  indications 
  of 
  spines 
  

   on 
  the 
  most 
  distal 
  only. 
  

  

  First 
  radials 
  visible, 
  second 
  exceedingly 
  wide 
  in 
  proportion 
  to 
  

   their 
  length, 
  in 
  contact 
  ; 
  the 
  third 
  almost 
  perfectly 
  triangular, 
  not 
  

   a 
  syzygy 
  ; 
  there 
  are 
  normally 
  three 
  distichals, 
  and 
  the 
  axillary 
  is 
  a 
  

   syzygy 
  ; 
  there 
  are 
  two 
  palniars 
  and 
  no 
  syzygy, 
  or 
  three 
  palmars 
  and 
  

   a 
  syzygy. 
  If 
  there 
  is 
  another 
  division 
  there 
  are 
  two 
  joints, 
  and 
  the 
  

   axillary 
  is 
  not 
  a 
  syzygy. 
  Arms 
  from 
  00-90. 
  

  

  