﻿194 
  COLLECTIOKS 
  FROM 
  MELANESIA, 
  

  

  at 
  the 
  distal 
  end 
  of 
  eacti 
  basal 
  antennal 
  joint 
  two 
  teeth, 
  whereof 
  one 
  

   is 
  directed 
  downward 
  and 
  one 
  outward. 
  The 
  legs 
  are 
  more 
  or 
  less 
  

   pubescent. 
  The 
  chelipedes 
  are 
  slender 
  ; 
  the 
  atm 
  or 
  merus-joint 
  

   denticulated 
  on 
  its 
  lower 
  surface, 
  and 
  armed 
  above 
  with 
  three 
  or 
  

   four 
  short 
  spines 
  ; 
  the 
  wrist 
  or 
  carpus 
  rather 
  obscurely 
  bicarinated 
  ; 
  

   hand 
  (in 
  both 
  sexes) 
  smooth, 
  slender, 
  naked, 
  somewhat 
  compressed, 
  

   and 
  twice 
  as 
  long 
  as 
  broad, 
  or 
  even 
  longer 
  ; 
  fingers 
  straight 
  and 
  

   acute. 
  The 
  ambulatory 
  legs 
  are 
  of 
  moderate 
  length 
  ; 
  the 
  merus- 
  

   joints 
  usually 
  bear 
  two 
  well-developed 
  distal 
  spines, 
  but 
  one 
  of 
  these 
  

   is 
  occasionally 
  absent 
  ; 
  there 
  is 
  usually 
  a 
  short 
  spine 
  or 
  tubercle 
  at 
  

   the 
  distal 
  end 
  of 
  the 
  following 
  joint, 
  which 
  is 
  most 
  distinct 
  in 
  the 
  

   first 
  pair 
  of 
  ambulatory 
  legs 
  ; 
  dactyli 
  slightly 
  curved. 
  Length 
  of 
  

   the 
  largest 
  specimen 
  (an 
  adult 
  female) 
  to 
  base 
  of 
  rostrum 
  about 
  1-^ 
  

   inch 
  (30 
  mm.), 
  of 
  rostral 
  spines 
  -^tj 
  inch 
  (15 
  mm.), 
  greatest 
  breadth 
  

   rather 
  over 
  -| 
  inch 
  (22 
  mm.) 
  ; 
  length 
  of 
  first 
  ambulatory 
  leg 
  about 
  

   1| 
  inch 
  (38 
  mm.). 
  

  

  There 
  are 
  in 
  the 
  first 
  collection 
  several 
  specimens 
  of 
  both 
  sexes 
  

   from 
  Port 
  Curtis, 
  7-11 
  fms. 
  (Nos. 
  85, 
  87). 
  In 
  the 
  second 
  collection 
  

   are 
  two 
  males 
  from 
  Thursday 
  Island, 
  3-4 
  fms. 
  (No. 
  175). 
  

  

  The 
  spines 
  of 
  the 
  dorsal 
  surface 
  of 
  the 
  carapace 
  vary 
  considerably 
  

   in 
  length. 
  

  

  Several 
  of 
  the 
  specimens 
  are 
  more 
  or 
  less 
  thickly 
  covered 
  with 
  an 
  

   overgrowth 
  of 
  Polyzoa 
  and 
  Sertularians 
  {Thuiaria 
  and 
  Grisia), 
  and 
  

   with 
  a 
  species 
  of 
  Zoanthus. 
  

  

  From 
  P. 
  aculeatiis, 
  as 
  described 
  by 
  Milne-Edwards, 
  this 
  variety 
  

   is 
  distinguished 
  only 
  by 
  the 
  form 
  of 
  the 
  postocular 
  spine 
  (see 
  fig. 
  A), 
  

   and 
  by 
  the 
  existence 
  (usually) 
  of 
  two 
  spines 
  at 
  the 
  distal 
  end 
  of 
  

   the 
  merus-joints 
  of 
  the 
  ambulatory 
  legs. 
  From 
  the 
  P. 
  halimoides, 
  

   recently 
  described 
  by 
  me, 
  it 
  is 
  distinguished 
  by 
  having 
  two 
  spines 
  

   on 
  each 
  branchial 
  region, 
  the 
  form 
  of 
  the 
  postocular 
  tooth, 
  &c. 
  

   Several 
  other 
  species 
  of 
  this 
  subgenus 
  have 
  been 
  described, 
  none 
  

   of 
  which, 
  are 
  to 
  be 
  confounded 
  with 
  P. 
  (Chlorinoides) 
  aculeatus. 
  

   P. 
  S2yatiilife>\ 
  Haswell, 
  a 
  species 
  dredged 
  at 
  Port 
  Stephen, 
  is 
  at 
  

   once 
  distinguished 
  by 
  its 
  bifurcated 
  rostral 
  spines, 
  &c. 
  

  

  11. 
  Hyastenus 
  diacanthus 
  {De 
  Ilaan). 
  

  

  A 
  male 
  and 
  three 
  females 
  of 
  this 
  very 
  common 
  species 
  are 
  retained 
  

   for 
  the 
  collection 
  from 
  Thursday 
  Island, 
  Torres 
  Straits, 
  3-6 
  fms. 
  

   (Nos. 
  130, 
  175), 
  one 
  was 
  received 
  from 
  Port 
  Denison, 
  another 
  from 
  

   Port 
  Molle, 
  14 
  fms. 
  (93), 
  another 
  from 
  Port 
  Curtis, 
  0-11 
  fms. 
  

   (92), 
  and 
  another 
  from 
  Port 
  Darwin 
  (12 
  fms.). 
  As 
  is 
  very 
  usual 
  

   with 
  H. 
  diaca7ithus, 
  these 
  specimens 
  are 
  more 
  or 
  less 
  covered 
  

   •with 
  sponges, 
  &c. 
  

  

  I 
  have 
  already 
  referred 
  to 
  the 
  synonyma 
  and 
  general 
  distribu- 
  

   tion 
  of 
  this 
  species 
  *. 
  

  

  In 
  a 
  very 
  small 
  female 
  in 
  the 
  collection, 
  from 
  Port 
  Denison, 
  

  

  * 
  Proc. 
  Zool. 
  Soc. 
  pp. 
  19, 
  26 
  (1879) 
  ; 
  Cat. 
  New-Zeal. 
  Crust, 
  p. 
  9 
  (1876). 
  

  

  