﻿688 
  I'nodEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  vol.xx. 
  

  

  tome 
  triangular, 
  bounded 
  behind 
  by 
  a 
  transverse 
  furrow, 
  apex 
  sub- 
  

   acute. 
  Basal 
  segment 
  of 
  antenna 
  devoid 
  of 
  spines, 
  neither 
  is 
  there 
  

   any 
  trace 
  of 
  an 
  external 
  spine 
  at 
  the 
  base 
  of 
  the 
  antenna! 
  scale; 
  the 
  

   latter 
  is 
  small, 
  broad, 
  its 
  inner 
  border 
  rounded, 
  its 
  outer 
  border 
  termi- 
  

   nating 
  in 
  a 
  long, 
  stout, 
  straight 
  tooth 
  or 
  si)ine. 
  Third 
  maxillipeds 
  

   hairy 
  witliiii. 
  Chelipeds 
  long, 
  usually 
  symmetrical 
  on 
  the 
  two 
  sides 
  of 
  

   the 
  body, 
  but 
  in 
  some 
  individuals 
  distinctly 
  unsymmetrical; 
  upper 
  

   margin 
  of 
  merus 
  lightly 
  serrate, 
  without 
  any 
  prominent 
  tooth; 
  lower 
  

   margins 
  armed 
  with 
  a 
  row 
  of 
  small, 
  blunt 
  teeth 
  or 
  tubercles, 
  lower 
  

   face 
  more 
  or 
  less 
  tuberculous, 
  inner 
  and 
  outer 
  faces 
  smooth 
  ; 
  carpus 
  

   short, 
  triangular, 
  superior 
  internal 
  margin 
  with 
  a 
  series 
  of 
  small 
  obso- 
  

   lescent 
  teeth 
  or 
  tubercles; 
  there 
  is 
  also 
  a 
  short 
  row 
  of 
  similar 
  teeth 
  

   near 
  the 
  external 
  lower 
  angle 
  of 
  the 
  carpus, 
  near 
  the 
  point 
  of 
  articula- 
  

   tion 
  with 
  the 
  chela; 
  chela 
  large 
  and 
  i^owerful, 
  palm 
  inflated, 
  outer 
  and 
  

   inner 
  faces 
  smooth, 
  suj)erior 
  margin 
  nearly 
  straight, 
  adorned 
  with 
  low, 
  

   squamous 
  tubercles 
  which 
  are 
  irregularly 
  disposed 
  in 
  two 
  rows; 
  the 
  

   inferior 
  margin 
  of 
  the 
  hand 
  is 
  convex, 
  and 
  is 
  similarly 
  ornamented 
  with 
  

   biserial, 
  de])ressed 
  obsolescent 
  tubercles 
  which 
  cease 
  at 
  the 
  base 
  of 
  the 
  

   immobile 
  finger. 
  The 
  fingers 
  are 
  conspicuously 
  marked 
  with 
  longitudi- 
  

   nal 
  rows 
  of 
  pits, 
  three 
  rows 
  on 
  each 
  finger; 
  the 
  cutting 
  edges 
  are 
  

   irregularly 
  toothed, 
  two 
  teeth 
  on 
  the 
  movable 
  finger 
  and 
  three 
  on 
  the 
  

   immovable 
  finger; 
  the 
  fingers 
  are 
  not 
  conspicuously 
  bearded. 
  The 
  

   median 
  carina 
  of 
  the 
  iuDer 
  branch 
  of 
  the 
  posterior 
  pair 
  of 
  abdominal 
  

   appendages 
  ends 
  near 
  the 
  hind 
  margin 
  without 
  developing 
  a 
  spine. 
  

  

  Dimensions 
  of 
  a 
  specimen: 
  Length 
  96 
  mm.; 
  carapace 
  48 
  mm.; 
  from 
  

   tip 
  of 
  rostrum 
  to 
  cervical 
  groove 
  32 
  mm.; 
  from 
  cervical 
  groove 
  to 
  ])0S- 
  

   terior 
  border 
  of 
  carapace 
  15.5 
  mm.; 
  width 
  of 
  areola 
  4.5 
  nam.; 
  length 
  

   of 
  cheliped 
  80 
  mm.; 
  length 
  of 
  merus 
  22 
  mm.; 
  length 
  of 
  carpus 
  17 
  

   mm.; 
  breadth 
  of 
  carjius 
  l-'l 
  mm.; 
  length 
  of 
  chela 
  39.5 
  mm.; 
  breadth 
  

   of 
  chela 
  18 
  mm.; 
  length 
  of 
  dactylus 
  25 
  mm. 
  

  

  In 
  the 
  number 
  and 
  arrangement 
  of 
  the 
  branchial 
  organs, 
  Parastacus 
  

   hassleri 
  agrees 
  with 
  P. 
  varicosus.^ 
  The 
  epipod 
  of 
  the 
  first 
  maxilliped 
  

   bears 
  gill 
  filaments, 
  as 
  in 
  the 
  latter 
  species, 
  the 
  podobranchi* 
  have 
  

   narrow 
  ahe, 
  the 
  posterior 
  arthrobranchia 
  of 
  the 
  thirteenth 
  somite 
  is 
  

   reduced 
  to 
  a 
  small 
  filament 
  which 
  bears 
  a 
  single 
  lateral 
  branch. 
  The 
  

   coxopoditic 
  sette 
  are 
  long 
  and 
  hooked 
  at 
  the 
  end. 
  

  

  Rahitat. 
  — 
  Talcahuano, 
  Chile, 
  Xo.3401, 
  Coll. 
  Mus.Oomp. 
  Zool., 
  (Hassler 
  

   Exped., 
  April, 
  1872). 
  One 
  hundred 
  specimens. 
  

  

  Astacus 
  ehilensis 
  Milne-Edwards,- 
  from 
  "the 
  coast 
  of 
  Chile," 
  is 
  not 
  

   described 
  with 
  enough 
  detail 
  to 
  be 
  determinable. 
  The 
  type, 
  however, 
  

   may 
  be 
  still 
  extant 
  in 
  Paris. 
  It 
  is 
  said 
  to 
  bear 
  a 
  close 
  resemblance 
  to 
  

   AstacKS 
  australasiensis 
  Milne- 
  Edwards,^' 
  but 
  to 
  diflter 
  from 
  the 
  latter 
  

   species 
  in 
  having 
  a 
  shorter 
  rostrum, 
  a 
  carpus 
  destitute 
  of 
  teeth 
  or 
  

  

  iPage 
  685. 
  

  

  2 
  Hist. 
  Nat. 
  des 
  Crnstact'-s, 
  II, 
  p. 
  .333, 
  1837. 
  

  

  ■■'Ibid., 
  II, 
  p. 
  332, 
  pi. 
  XXIV, 
  ligs. 
  1-5, 
  1837. 
  

  

  