﻿G(;8 
  rnocEEDiXGS 
  of 
  the 
  xatioxal 
  museum. 
  

  

  First 
  abdominal 
  somite 
  devoid 
  of 
  appendages 
  in 
  botli 
  sexes; 
  podo- 
  

   branchiie 
  lacking 
  a 
  bilobed 
  plaited 
  lamina, 
  although 
  the 
  stem 
  inay 
  be 
  

   ex])andod 
  into 
  a 
  wing; 
  cpipod 
  of 
  first 
  maxilliped 
  generally 
  furnished 
  

   witli 
  branchial 
  fihunents, 
  coxopoditic 
  seta' 
  hooked 
  at 
  the 
  end; 
  telsou 
  

   not 
  divided 
  by 
  a 
  transverse 
  suture. 
  

  

  ASTACOIDES 
  Guerin. 
  

   Jstaco'ides 
  Gitkkin, 
  Rcvne 
  Zoolo<^iqne, 
  II, 
  j). 
  109, 
  1839. 
  

   Typo, 
  Axtacokhs 
  (joudot'd 
  Gnf'rin=iJs^rtc«.s 
  mada;/a>icarie)isis 
  Andonin 
  et 
  Milne-Etlwards. 
  

  

  Kostrum 
  short, 
  (piadrilateral, 
  concave 
  above, 
  margins 
  furnished 
  with 
  

   small 
  teeth 
  or 
  tubercles. 
  Antennal 
  scale 
  very 
  small.' 
  Anterior 
  process 
  

   of 
  epistome 
  long 
  triangular. 
  Superior 
  border 
  of 
  the 
  hand 
  dentate. 
  

   Sides 
  of 
  the 
  carapace 
  armed 
  with 
  small 
  tubercles, 
  some 
  of 
  which 
  assume 
  

   the 
  form 
  of 
  small 
  spines. 
  Number 
  of 
  well-developed 
  gills 
  reduced 
  to 
  

   twelve 
  on 
  each 
  side 
  of 
  the 
  body; 
  posterior 
  arthrobranchia^ 
  rudimentary 
  

   and 
  functionless; 
  one 
  pair 
  of 
  pleurobranchia^ 
  (on 
  the 
  fourteenth 
  somite); 
  

   the 
  branchial 
  formula, 
  according 
  to 
  Huxley,- 
  being 
  as 
  follows 
  : 
  

  

  Arthrob 
  RANCH 
  i;r.. 
  

  

  Somite. 
  PonOBRANCHiiE. 
  . 
  . 
  Pledrobranchi^. 
  

  

  Anterior. 
  Posterior. 
  

   VII. 
  . 
  . 
  . 
  O(opr) 
  .. 
  .... 
  .... 
  = 
  0(ep/-) 
  

   VII]. 
  ... 
  1 
  ..../•.... 
  .... 
  = 
  l 
  + 
  j- 
  

   IX. 
  . 
  . 
  . 
  1 
  . 
  . 
  . 
  . 
  1 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  = 
  2 
  

  

  X. 
  ... 
  1 
  .... 
  1 
  r 
  .... 
  = 
  2 
  + 
  r 
  

  

  XI. 
  ... 
  1 
  .... 
  1 
  ..../•.... 
  = 
  2 
  + 
  r 
  

  

  XII. 
  ... 
  1 
  .... 
  1 
  .... 
  r 
  .... 
  = 
  2 
  + 
  r 
  

  

  XIII. 
  ... 
  1 
  .... 
  1 
  ....;•.... 
  = 
  2 
  + 
  r 
  

  

  XIV. 
  ... 
  .... 
  .... 
  .... 
  1 
  =1 
  

  

  fi 
  + 
  epr 
  + 
  5 
  + 
  r 
  + 
  4r 
  + 
  1 
  = 
  12 
  + 
  5r 
  + 
  ei)r 
  

  

  One 
  species 
  known. 
  

   Habitat. 
  — 
  Madagascar. 
  

  

  ASTACOIDES 
  MADAGASCARIENSIS 
  (Audouin 
  et 
  Milne-Edwards). 
  

  

  AslacHs 
  madafjascaricnsis 
  Audouin 
  kt 
  Milne-Ed 
  ward.s, 
  .Joiiin. 
  de 
  I'Institut, 
  1839, 
  

  

  p. 
  152; 
  Arch, 
  du 
  Miis. 
  d'Hist. 
  Nat., 
  11, 
  p. 
  35, 
  pi. 
  hi, 
  1841. 
  

   Astacoides 
  riondotu 
  Gukrix, 
  Revno 
  Zoologiqne, 
  II, 
  p. 
  109, 
  1839.^ 
  

   Astaeus 
  (Astaro'idcs) 
  madatjascaricnsis 
  Fiiucusos, 
  Arch. 
  f. 
  Naturgesch., 
  12ter 
  Jabrg., 
  

   I, 
  p. 
  89, 
  1846. 
  

  

  'Erroneously 
  said 
  to 
  be 
  wanting 
  by 
  Gn^rin. 
  

  

  -Proc. 
  Zool. 
  .See. 
  TyOiidon, 
  1878, 
  p. 
  775. 
  

  

  ^Gui'-rin's 
  description 
  of 
  the 
  Madagascar 
  crayfish 
  must 
  have 
  been 
  published 
  about 
  

   the 
  same 
  time 
  as 
  Andonin 
  and 
  Milne-Edwards's. 
  The 
  Eevue 
  Zoologique 
  was 
  issued 
  

   monthly. 
  Gat'rin's 
  description 
  occnrs 
  in 
  the 
  April 
  number, 
  1839. 
  Audouin 
  anil 
  

   Milne-Edwards's 
  description 
  in 
  the 
  Institute, 
  p. 
  152, 
  was 
  communicated 
  to 
  the 
  

   Socicte 
  Philoniatiiine 
  on 
  the 
  27th 
  of 
  April, 
  1839. 
  In 
  cases 
  like 
  this 
  it 
  seems 
  reason- 
  

   able 
  to 
  retain 
  the 
  name 
  adopted 
  by 
  the 
  next 
  following 
  author 
  who 
  treated 
  of 
  thi^ 
  

   species 
  — 
  in 
  this 
  instance, 
  Audouin 
  and 
  Milne-Edwards 
  mi 
  the 
  Archives 
  du 
  Museum 
  

   d' 
  Histoire 
  Naturelle, 
  II, 
  1811. 
  

  

  