﻿268 
  COllECTIONS 
  FKOM 
  MELANESIA. 
  

  

  From 
  most 
  of 
  its 
  congeners 
  tliis 
  species 
  is 
  distinguished 
  by 
  the 
  

   absence 
  of 
  a 
  distinct 
  rostrum, 
  and 
  the 
  form 
  and 
  armature 
  of 
  the 
  

   larger 
  chelipede 
  ; 
  the 
  latter 
  character 
  will 
  distinguish 
  it 
  from 
  E. 
  

   tricarinahis 
  and 
  E. 
  acantholejpis, 
  Stimpson, 
  from 
  Japan 
  and 
  Port 
  

   Jackson, 
  species 
  in 
  which 
  the 
  rostrum 
  is 
  absent. 
  From 
  the 
  fore- 
  

   going 
  species 
  it 
  is 
  at 
  once 
  distinguished 
  by 
  the 
  longer, 
  slenderer 
  

   eye-peduncles 
  with 
  shorter 
  basal 
  scales, 
  the 
  form 
  of 
  the 
  chelae, 
  

   slenderer 
  ambulatory 
  legs, 
  &c. 
  

  

  11. 
  Petrolisthes 
  japonicus 
  {De 
  Haan), 
  var. 
  inermis, 
  Haswell. 
  

  

  Port 
  MoUe 
  (No. 
  103), 
  several 
  specimens 
  obtained 
  on 
  the 
  beach 
  

   between 
  tide-marks; 
  Port 
  Curtis, 
  7-11 
  fms. 
  (j^o. 
  85), 
  several 
  

   specimens. 
  

  

  Other 
  specimens 
  are 
  in 
  the 
  collection 
  of 
  the 
  British 
  Museum 
  from 
  

   Faciug 
  Island, 
  Port 
  Curtis 
  (J. 
  MacgiUivray, 
  H.M.S. 
  'Rattlesnake'); 
  

   and 
  a 
  small 
  example 
  from 
  Shark 
  Bay, 
  W. 
  Australia 
  {F. 
  M. 
  Rayner, 
  

   H.M.S. 
  'Herald'), 
  probably 
  belongs 
  here. 
  

  

  This 
  species 
  is 
  closely 
  allied 
  to 
  the 
  well-known 
  New-Zealand 
  

   P. 
  elongatiis, 
  M.-Edwards, 
  but 
  the 
  chelipedes 
  have 
  a 
  longer, 
  slenderer 
  

   wrist, 
  and 
  the 
  palm 
  is 
  slenderer 
  and 
  its 
  outer 
  margin 
  is 
  straight, 
  not 
  

   arcuated. 
  The 
  variety 
  inermis 
  is 
  distinguished 
  by 
  Mr. 
  Haswell 
  by 
  

   having 
  two 
  spines 
  near 
  the 
  distal 
  end 
  of 
  the 
  posterior 
  margin 
  of 
  the 
  

   wrist, 
  not 
  three 
  as 
  in 
  P. 
  elongatus. 
  De 
  Haan 
  in 
  his 
  description 
  of 
  

   P. 
  japonicus 
  mentions 
  three, 
  but 
  figures 
  two 
  only. 
  The 
  wrist 
  is 
  even 
  

   longer 
  and 
  the 
  palm 
  more 
  roughened 
  above 
  tlian 
  in 
  the 
  Australian 
  

   specimens 
  ; 
  and 
  the 
  second 
  pair 
  of 
  legs 
  only 
  has 
  the 
  merus-joint 
  

   bispinulose 
  at 
  apex. 
  

  

  The 
  Japanese 
  species 
  Petrolisthes 
  pidcliripes., 
  designated 
  by 
  White 
  

   Porcellana 
  pulchripes 
  (List 
  Cr. 
  Brit. 
  Mus. 
  p. 
  129, 
  18-17), 
  of 
  which 
  the 
  

   type, 
  from 
  the 
  Madjica-Sima 
  group, 
  is 
  in 
  the 
  collection 
  of 
  the 
  British 
  

   Museum, 
  is 
  closely 
  allied 
  to 
  the 
  foregoing 
  ; 
  but 
  the 
  chelipedes 
  have 
  

   a 
  short 
  thick 
  carpus, 
  which 
  is 
  much 
  shorter 
  than 
  the 
  cej^halothorax, 
  

   and 
  has 
  three 
  teeth 
  on 
  its 
  posterior 
  margin 
  ; 
  the 
  distal 
  end 
  of 
  the 
  

   merus-joints 
  of 
  both 
  second 
  and 
  third 
  ambulatory 
  legs 
  is 
  unarmed. 
  

  

  12. 
  Petrolisthes 
  lamarckii 
  {Leach). 
  

  

  Here 
  are 
  referred 
  several 
  specimens 
  found 
  on 
  the 
  beach 
  at 
  Flinders 
  

   Island, 
  and 
  one 
  obtained 
  between 
  tide-marks 
  at 
  Port 
  MoUe 
  (No. 
  103). 
  

   These 
  examples 
  are 
  of 
  small 
  size 
  ; 
  the 
  front 
  is 
  triangulate, 
  somewhat 
  

   deflexed, 
  sinuated 
  on 
  the 
  margins, 
  concave 
  in 
  the 
  middle 
  line 
  above, 
  

   narrowed 
  to 
  the 
  apex, 
  which 
  is 
  rounded 
  ; 
  there 
  is 
  a 
  very 
  distinct 
  

   postocular 
  s^jine 
  on 
  the 
  lateral 
  margins 
  of 
  the 
  carapace 
  ; 
  the 
  chelipedes 
  

   are 
  closely 
  granulated 
  above 
  ; 
  the 
  arm 
  has 
  a 
  blunt 
  tooth 
  at 
  the 
  distal 
  

   end 
  of 
  its 
  inner 
  margin 
  ; 
  the 
  inner 
  margin 
  of 
  the 
  wrist 
  has 
  three 
  

   triangular, 
  not 
  very 
  distant 
  teeth, 
  which 
  decrease 
  in 
  size 
  from 
  the 
  

   first 
  to 
  the 
  last 
  ; 
  at 
  the 
  distal 
  end 
  of 
  the 
  posterior 
  margin 
  are 
  three 
  

   small 
  spines. 
  Colour 
  reddish 
  or 
  yellowish 
  ; 
  the 
  first 
  and 
  . 
  second 
  

   ambulatory 
  legs 
  (where 
  the 
  coloration 
  is 
  best 
  preserved) 
  have 
  the 
  

  

  