﻿CEUSTACEA. 
  277 
  

  

  slender 
  penultimate 
  joint 
  of 
  the 
  first 
  to 
  third 
  ambulatory 
  legs 
  ; 
  the 
  

   short, 
  curved 
  dactyli 
  are 
  armed 
  on 
  their 
  lower 
  margins 
  with 
  a 
  strong 
  

   accessory 
  claw, 
  posterior 
  to 
  which 
  are 
  one 
  or 
  two 
  more 
  small 
  teeth. 
  

   Colour 
  (in 
  spirit) 
  yellowish. 
  Length 
  of 
  carapace 
  about 
  2| 
  lines 
  

   (5| 
  millim.), 
  breadth 
  nearly 
  2 
  lines 
  (4 
  millim.). 
  

  

  This 
  species 
  is 
  scarcely 
  distinguished 
  from 
  the 
  typical 
  Porcellana 
  

   latifrons, 
  Stimpson, 
  except 
  bj" 
  the 
  somewhat 
  different 
  deutieulation 
  of 
  

   the 
  lobes 
  of 
  the 
  front, 
  and 
  in 
  the 
  latter 
  having, 
  as 
  it 
  would 
  seem, 
  the 
  

   posterior 
  margin 
  of 
  the 
  wrist 
  armed, 
  as 
  well 
  as 
  the 
  anterior, 
  with 
  three 
  

   spines. 
  The 
  specimens 
  described 
  by 
  Stimpson 
  were 
  from 
  Hong 
  Kong. 
  

   Porcellana 
  armata, 
  Dana, 
  has 
  a 
  much 
  less 
  prominent 
  front. 
  

  

  Porcellana 
  streptocliiras 
  of 
  White*, 
  from 
  the 
  Philippines, 
  is, 
  I 
  

   think, 
  a 
  mere 
  variety 
  of 
  this 
  species. 
  It 
  differs 
  only 
  in 
  the 
  somewhat 
  

   broader 
  carapace, 
  in 
  having 
  the 
  frontal 
  lobes 
  armed 
  with 
  more 
  nume- 
  

   rous 
  spinules, 
  and 
  in 
  having 
  the 
  under 
  surface 
  of 
  the 
  merus 
  of 
  the 
  

   chelipedes 
  armed 
  with 
  three 
  or 
  four 
  spines 
  in 
  place 
  of 
  the 
  single 
  

   spine 
  in 
  P. 
  quadrilobata 
  ; 
  and 
  these 
  characters 
  are 
  possibly 
  duo 
  to 
  

   the 
  greater 
  age 
  of 
  the 
  specimens. 
  

  

  In 
  one 
  of 
  AYhite's 
  specimens 
  the 
  wrist 
  is 
  tridentate, 
  in 
  the 
  other 
  it 
  

   is 
  subentire. 
  

  

  This 
  species, 
  in 
  its 
  elongated 
  carapace 
  and 
  slender 
  chelipedes, 
  

   establishes 
  a 
  transition 
  to 
  the 
  genus 
  (or 
  subgenus) 
  Porcellanella, 
  the 
  

   species 
  of 
  which 
  have 
  a 
  prominent 
  and 
  tridentate 
  front. 
  The 
  genera 
  

   of 
  the 
  Porccllanidca 
  stand 
  much 
  in 
  need 
  of 
  revision 
  ; 
  and 
  I 
  may 
  add 
  

   that 
  I 
  doubt 
  the 
  constancy 
  of 
  the 
  characters 
  derived 
  by 
  Stimpson 
  

   from 
  the 
  size 
  and 
  number 
  of 
  the 
  dcnticulations 
  of 
  the 
  dactyli 
  of 
  the 
  

   ambulatory 
  legs 
  as 
  generic 
  distinctions. 
  

  

  There 
  are 
  in 
  the 
  collection 
  three 
  small 
  specimens 
  from 
  Thursday 
  

   Island, 
  4-5 
  fms. 
  (No. 
  165), 
  which 
  in 
  many 
  of 
  their 
  characters 
  are 
  

   closely 
  allied 
  to 
  P. 
  serratifrons, 
  Stimpson, 
  yet 
  are 
  probably 
  distinct, 
  

   but 
  to 
  which, 
  on 
  account 
  of 
  their 
  very 
  imperfect 
  condition, 
  I 
  will 
  

   not 
  apply 
  a 
  specific 
  designation. 
  In 
  one 
  specimen 
  the 
  chelipede 
  is 
  

   pi'obably 
  aborted, 
  having 
  the 
  palm 
  narrow 
  and 
  twisted 
  and 
  the 
  

   fingers 
  abnormally 
  developed. 
  These 
  specimens 
  are 
  further 
  distin- 
  

   guished 
  fj'om 
  P. 
  serratifrons 
  by 
  having 
  three 
  (not 
  1 
  or 
  2) 
  spinules 
  on 
  

   the 
  sides 
  of 
  the 
  branchial 
  regions, 
  six 
  to 
  eight 
  spines 
  on 
  the 
  anterior, 
  

   and 
  two 
  on 
  the 
  posterior 
  margin 
  of 
  the 
  carpus 
  of 
  the 
  chelipede, 
  &c. 
  

   In 
  the 
  single 
  specimen 
  (a 
  young 
  one) 
  possessing 
  both 
  chelipedes 
  the 
  

   lower 
  margins 
  of 
  both 
  right 
  and 
  left 
  palms 
  are 
  spinulose. 
  

  

  21. 
  Galathea 
  australiensis, 
  Stimpson. 
  (Plate 
  XXXI. 
  fig. 
  A.) 
  

  

  Here 
  are 
  referred 
  a 
  male 
  from 
  Port 
  Denison, 
  4 
  fms. 
  (No. 
  Ill), 
  

   and 
  another 
  from 
  Port 
  Molle, 
  14 
  fms. 
  (No. 
  93), 
  in 
  the 
  first 
  collec- 
  

   tion; 
  also 
  a 
  series 
  of 
  seven 
  sj^ecimens 
  from 
  theArafuraSea, 
  32-36 
  fms. 
  

   (No. 
  160), 
  in 
  the 
  second 
  collection, 
  among 
  which 
  are 
  both 
  males 
  and 
  

   females. 
  Stimpson's 
  description 
  was 
  from 
  a 
  female. 
  In 
  the 
  adult 
  

   males 
  I 
  have 
  examined 
  the 
  palms 
  are 
  broader 
  and 
  the 
  fingers 
  have 
  

   between 
  them 
  a 
  hiatus 
  when 
  closed, 
  and 
  are 
  strongly 
  toothed 
  on 
  their 
  

   * 
  List 
  Crust. 
  Brit. 
  Mus. 
  p. 
  Gl 
  (1847), 
  descript. 
  nulla. 
  

  

  