﻿238 
  'COLLECTIONS 
  FROM 
  MELANESIA. 
  

  

  than 
  its 
  greatest 
  vertical 
  depth, 
  which 
  is 
  at 
  the 
  articulation 
  with 
  

   the 
  mobile 
  finger, 
  smooth 
  and 
  polished 
  externally, 
  its 
  upper 
  margin 
  

   not 
  carinated, 
  its 
  inner 
  surface 
  with 
  a 
  dense 
  patch 
  of 
  hair 
  ; 
  the 
  

   lower 
  margin 
  of 
  the 
  immobile 
  fiuger 
  is 
  in 
  a 
  straight 
  line 
  with 
  the 
  

   lower 
  margin 
  of 
  the 
  palm, 
  its 
  upper 
  or 
  inner 
  margin 
  is 
  denticulated 
  

   and 
  has 
  a 
  strong 
  tooth 
  or 
  lobe 
  in 
  the 
  middle 
  ; 
  the 
  inner 
  margin 
  of 
  

   the 
  mobile 
  finger 
  has 
  a 
  smaller 
  tooth 
  near 
  its 
  base 
  ; 
  the 
  fingers, 
  

   when 
  closed, 
  meet 
  only 
  toward 
  their 
  apices, 
  having 
  an 
  hiatus 
  be- 
  

   tween 
  them, 
  which 
  is 
  hollowed 
  out 
  into 
  a 
  deep, 
  nearly 
  semicircular 
  

   cavity 
  at 
  the 
  base 
  of 
  the 
  immobile 
  finger 
  ; 
  this 
  cavity 
  is 
  margined 
  

   with 
  hairs. 
  The 
  ambulatory 
  legs 
  are 
  slender, 
  somewhat 
  compressed, 
  

   and 
  the 
  margins 
  somewhat 
  thinly 
  clothed 
  with 
  hair. 
  Colour, 
  in 
  

   spirit, 
  brownish. 
  Length 
  of 
  carapace 
  nearly 
  3 
  lines 
  (6 
  millim,), 
  

   breadth 
  3| 
  lines 
  (somewhat 
  over 
  7 
  millim.) 
  ; 
  length 
  of 
  chelipede 
  

   about 
  Sg 
  lines 
  (over 
  11 
  millim.). 
  

  

  The 
  single 
  specimen 
  (a 
  male) 
  was 
  obtained 
  at 
  Port 
  Jackson, 
  

   5-7 
  fms. 
  (No. 
  104). 
  

  

  In 
  the 
  relatively 
  narrow 
  and 
  quadrate 
  carapace 
  this 
  species 
  may 
  

   be 
  compared 
  to 
  such 
  forms 
  as 
  Macrojjlithalnms 
  pacificus, 
  Dana 
  *, 
  

   to 
  which 
  species 
  apparently 
  belong 
  specimens 
  recently 
  received 
  from 
  

   Timor 
  Laut 
  (//. 
  0. 
  Forbes), 
  Macrophtlialmus 
  hicarinatus. 
  Heller 
  f, 
  

   and 
  M. 
  qaadratus, 
  A. 
  Milne-Edwards 
  %. 
  

  

  M. 
  jyacificus 
  and 
  M. 
  bicarinatus 
  difi^er 
  in 
  their 
  narrower 
  front, 
  

   &c. 
  ; 
  M. 
  quadratus 
  has 
  but 
  two 
  lateral 
  marginal 
  teeth, 
  and 
  no 
  lobe 
  

   or 
  tooth 
  on 
  the 
  inner 
  margin 
  of 
  the 
  immobile 
  finger. 
  Macroplv- 
  

   thalmus 
  setoaus, 
  an 
  Australian 
  species 
  very 
  briefly 
  characterized 
  by 
  

   Milne- 
  Edwards 
  §, 
  has, 
  I 
  suppose, 
  a 
  wider 
  carapace. 
  Specimens 
  

   provisionally 
  referred 
  to 
  this 
  species 
  in 
  the 
  British-Museum 
  collec- 
  

   tion 
  are 
  certainly 
  veiy 
  distinct 
  from 
  our 
  new 
  species. 
  

  

  Macrophtludmus 
  latifrons, 
  Haswell 
  ||, 
  from 
  Port 
  Phillip, 
  has 
  the 
  

   carapace 
  finely 
  granulated, 
  the 
  immobile 
  finger 
  of 
  the 
  chelipedes 
  

   deflexed, 
  &c. 
  

  

  In 
  many 
  of 
  its 
  characters 
  our 
  species 
  approaches 
  Euplax 
  {Choeno- 
  

   stoma) 
  boscii 
  and 
  E. 
  crassimanus, 
  Stimpson, 
  in 
  both 
  of 
  which 
  there 
  

   are 
  but 
  two 
  teeth 
  on 
  the 
  lateral 
  margins 
  of 
  the 
  carapace. 
  In 
  

   Hemiplax 
  Mrtipes, 
  Heller, 
  not 
  to 
  mention 
  other 
  distinctions, 
  the 
  

   fingers 
  are 
  only 
  minutely 
  denticulated 
  on 
  their 
  inner 
  margins. 
  In 
  

   the 
  absence 
  of 
  catalogues 
  or 
  systematic 
  lists 
  of 
  the 
  species, 
  it 
  is 
  with 
  

   great 
  hesitation 
  that 
  I 
  venture 
  to 
  describe 
  this 
  as 
  a 
  new 
  form 
  among 
  

   80 
  many 
  nearly 
  allied 
  species. 
  

  

  83. 
  Euplax 
  (Chsenostoma) 
  boscii 
  (Audouin). 
  

  

  A 
  small 
  male 
  is 
  in 
  the 
  collection 
  from 
  Port 
  MoUe 
  (No. 
  95). 
  

   This 
  example 
  in 
  its 
  coloration 
  and 
  all 
  other 
  cliaracteristics 
  coin- 
  

  

  * 
  U.S. 
  Exploring 
  Expedition, 
  Crust, 
  xiii. 
  p. 
  314, 
  pi. 
  six. 
  fig. 
  4 
  (1852). 
  

  

  t 
  Reise 
  der 
  Novara, 
  Crust, 
  p. 
  36. 
  pi. 
  iv. 
  fig. 
  2 
  (18(J5). 
  

  

  + 
  Nouv. 
  Archiv. 
  Mus. 
  Hist. 
  Nat. 
  ix. 
  p. 
  280, 
  pi. 
  xii. 
  fig. 
  6 
  (1873). 
  

  

  § 
  Ann. 
  Sci. 
  Nat. 
  ser. 
  3, 
  Zool. 
  xviii. 
  p. 
  159 
  (1852). 
  

  

  II 
  Catalogue, 
  p. 
  90 
  (1882). 
  

  

  