﻿158 
  COLLECTIONS 
  FROM 
  MELANESIA. 
  

  

  Arm 
  about 
  30 
  millim. 
  loug, 
  cirri 
  7 
  millim., 
  diameter 
  of 
  disk 
  

   3'5 
  millim. 
  

  

  Colour 
  creamy 
  white, 
  in 
  spirit. 
  

  

  Port 
  Jackson, 
  0-5 
  fms. 
  

  

  The 
  above 
  description 
  was 
  originally 
  drawn 
  up 
  from 
  the 
  single 
  

   specimen 
  received 
  from 
  the 
  ' 
  Alert,' 
  which 
  in 
  spirit 
  had 
  a 
  creamy- 
  

   white 
  colour 
  and 
  appeared 
  to 
  be 
  hardly 
  mature. 
  Since 
  its 
  arrival 
  

   the 
  Museum 
  has 
  acquired 
  specimens 
  from 
  Nelson's 
  J3ay, 
  which 
  are 
  

   no 
  larger 
  and 
  are 
  a 
  little 
  darker 
  or 
  grey 
  in 
  colour; 
  these 
  specimens, 
  

   of 
  which 
  I 
  have 
  been 
  able 
  to 
  examine 
  a 
  number, 
  bear 
  witness 
  to 
  their 
  

   maturity 
  by 
  the 
  presence 
  of 
  a 
  large 
  number 
  of 
  ova 
  attached 
  to 
  the 
  

   pinnules. 
  

  

  6. 
  Antedon 
  bidens. 
  (Plate 
  XI, 
  figs. 
  A, 
  a-c.) 
  

  

  Centrodorsal 
  prominent 
  ; 
  about 
  20 
  cirri, 
  with 
  about 
  20 
  joints, 
  a 
  

   number 
  of 
  which 
  have 
  two 
  minute 
  processes 
  on 
  their 
  dorsal 
  side 
  ; 
  

   the 
  penultimate 
  spine 
  is 
  small 
  ; 
  none 
  of 
  the 
  joints 
  are 
  distinctly 
  

   longer 
  than 
  broad, 
  but 
  a 
  number 
  of 
  them 
  have 
  a 
  shallow 
  lateral 
  ex- 
  

   cavation 
  along 
  their 
  distal 
  edge. 
  

  

  First 
  radials 
  jnst 
  visible; 
  second 
  very 
  wide, 
  in 
  contact; 
  third 
  almost 
  

   triangular, 
  not 
  quite 
  twice 
  as 
  long 
  as 
  the 
  second, 
  and 
  forming 
  a 
  

   convex 
  protuberance 
  with 
  it. 
  Ten 
  arms. 
  First 
  brachials 
  in 
  contact, 
  

   a 
  little 
  wider 
  on 
  their 
  outer 
  than 
  their 
  inner 
  side, 
  as 
  are 
  also 
  the 
  

   second 
  brachials, 
  which 
  form 
  with 
  the 
  first 
  a 
  convex 
  protuberance 
  ; 
  

   the 
  third 
  brachials, 
  which 
  are 
  syzygies, 
  have 
  a 
  sharp 
  distal 
  edge, 
  as 
  

   have 
  the 
  succeeding 
  joints 
  ; 
  these 
  soon 
  become 
  wedge-shaped, 
  and 
  

   form 
  a 
  strong 
  overlap 
  on 
  either 
  side 
  alternately 
  ; 
  after 
  some 
  time 
  

   this 
  diminishes, 
  and 
  the 
  more 
  terminal 
  joints 
  of 
  the 
  arm 
  form 
  rather 
  

   bead-like 
  swellings 
  on 
  either 
  side. 
  

  

  Syzygies 
  3, 
  9, 
  14 
  ; 
  4-6 
  joints 
  between 
  the 
  succeeding 
  syzygies. 
  

  

  The' 
  first 
  pinnule 
  is 
  very 
  stiff 
  and 
  long, 
  with 
  the 
  most 
  proximal 
  

   joint 
  the 
  longest 
  ; 
  it 
  is 
  placed 
  on 
  the 
  second 
  brachial, 
  has 
  some 
  12 
  

   joints, 
  of 
  which 
  the 
  more 
  basal 
  are 
  much 
  longer 
  than 
  broad, 
  and 
  

   which 
  are 
  also 
  stouter 
  than 
  those 
  on 
  the 
  sixth 
  brachial, 
  which, 
  

   again, 
  are 
  a 
  little 
  stouter 
  than 
  those 
  on 
  the 
  fourth. 
  The 
  pinnules 
  

   then 
  gradually 
  diminish 
  in 
  size, 
  and 
  then 
  again 
  increase 
  further 
  

   out. 
  

  

  The 
  arms 
  are 
  stiff, 
  and 
  somewhat 
  compressed 
  from 
  side 
  to 
  side 
  : 
  

   they 
  are 
  about 
  45 
  millim. 
  long 
  ; 
  diameter 
  of 
  disk 
  5 
  millim., 
  of 
  centro- 
  

   dorsal 
  3-3 
  ; 
  length 
  of 
  cirri 
  about 
  8 
  millim. 
  

  

  The 
  original 
  colour 
  was 
  probably 
  purple. 
  

  

  Torres 
  Straits. 
  

  

  7. 
  Antedon 
  loveni. 
  (Plate 
  X. 
  figs. 
  ^, 
  a-e.) 
  

  

  Centrodorsal 
  large, 
  as 
  large 
  as 
  the 
  disk, 
  excavated 
  in 
  the 
  centre, 
  

   with 
  about 
  20 
  cirrus-sockets 
  (cirri 
  lost). 
  

  

  First 
  radials 
  just 
  visible, 
  second 
  oblong 
  with 
  a 
  convex 
  median 
  

   protuberance 
  along 
  their 
  distal 
  edge 
  ; 
  axillary 
  pentagonal, 
  not 
  a 
  

  

  