﻿662 
  ROCEEDTXGS 
  OF 
  THE 
  NATroyjL 
  MUSEUM. 
  

  

  In 
  some 
  respects 
  C. 
  montezumcc 
  duf/esii 
  shows 
  an 
  approach 
  toward 
  

   this 
  species, 
  but 
  tlie 
  two 
  forms 
  can 
  not 
  be 
  confoumled 
  on 
  account 
  of 
  

   the 
  greater 
  sleuderuess 
  of 
  C. 
  chaimlanus^ 
  the 
  great 
  length 
  of 
  the 
  ros- 
  

   tral 
  and 
  jmstorbital 
  spines, 
  etc. 
  (J. 
  shvfeldtii 
  is 
  distinguished 
  from 
  (J. 
  

   chapalamis 
  by 
  the 
  presence 
  of 
  lateral 
  spines 
  on 
  the 
  carapace, 
  broader 
  

   rostrum, 
  differently 
  shaped 
  male 
  appendages, 
  etc. 
  

  

  Genus 
  ASTACUS 
  Fabricius 
  (s. 
  3.).' 
  

  

  < 
  Cancer 
  LiNN.EUS, 
  Syst. 
  Nat., 
  lOtli 
  ert., 
  I, 
  p. 
  625, 
  1758. 
  

  

  <^Astacus 
  Faijricius, 
  Syst. 
  Entomol., 
  p. 
  413, 
  1775; 
  Si)ecies 
  Insectoruni, 
  I, 
  p. 
  514, 
  

  

  1781; 
  Mantissa 
  Insectbrum, 
  I, 
  p. 
  331, 
  1787 
  ; 
  Entomol. 
  Syst. 
  emend., 
  II, 
  p. 
  478, 
  

  

  1793; 
  Suppl. 
  Entomol. 
  Syst., 
  p. 
  382, 
  1798. 
  

   <^Astacus 
  Latreillk, 
  Considerations 
  G^ncrales, 
  p. 
  101, 
  1810 
  (Astacne 
  JiuviaiiUn 
  

  

  Fabricius 
  = 
  Cancer 
  astacus 
  Lixx.eus, 
  specified 
  as 
  tlu- 
  type, 
  p. 
  422). 
  

   <^AstacKs 
  Leach, 
  Edinb. 
  Encycl., 
  VII, 
  p. 
  398, 
  1814; 
  Trans. 
  Liun. 
  Soc. 
  London, 
  

  

  XV, 
  pp. 
  336, 
  343, 
  1815. 
  

   <^ 
  PotavwMus 
  Leach, 
  Samonelle's 
  Entomologist's 
  Useful 
  Compendium, 
  p. 
  95, 
  

  

  1819 
  (Type, 
  Potamohius 
  Jiuciatilis= 
  Cancer 
  astaciis 
  Linnaeus). 
  

  

  < 
  Astacus 
  Milne-Edwards, 
  Hist. 
  Nat. 
  Crust., 
  II, 
  p. 
  329, 
  1837. 
  

  

  ^^^Astacus 
  (subgenus) 
  Erichson, 
  Arch. 
  f. 
  Naturgescli., 
  12ter 
  Jahrg., 
  I, 
  p. 
  90, 
  1846. 
  

   Type, 
  Cancer 
  astacus 
  Linna?iis. 
  

   The 
  genus 
  Astacus, 
  as 
  first 
  established 
  by 
  Fabricius,- 
  included 
  eiglit- 
  

   een 
  species. 
  The 
  dismemberment 
  of 
  this 
  heterogeneous 
  assemblage 
  

   was 
  begun 
  by 
  Fabricius 
  himself 
  in 
  1781," 
  by 
  the 
  removal 
  of 
  three 
  

   species 
  to 
  the 
  genus 
  Squilla. 
  In 
  1798,^ 
  he 
  eliminated 
  several 
  other 
  

   species 
  from 
  Astacus, 
  forming 
  for 
  their 
  reception 
  the 
  genera 
  Craugon, 
  

   Alpheus, 
  Falccmon, 
  and 
  Palinurus. 
  As 
  left 
  by 
  its 
  founder 
  in 
  1798, 
  the 
  

   genus 
  Astacus 
  contained 
  only 
  five 
  of 
  the 
  original 
  species, 
  namely, 
  A. 
  

   mariwus 
  { 
  = 
  Cancer 
  (jammariis 
  Linnieus), 
  A. 
  fluviatiUs 
  { 
  = 
  Cancer 
  

   astacus 
  Linnseus), 
  A. 
  ccerulescens, 
  A. 
  fuUjens, 
  and 
  A. 
  norvegicus. 
  Two 
  

   of 
  these, 
  ccent/escews 
  and/M?^e?i&, 
  are 
  indeterminable. 
  In 
  1810 
  Latreille,'^ 
  

  

  'Those 
  who 
  accept 
  the 
  genera 
  defined 
  by 
  i)olynomia]ists 
  after 
  the 
  year 
  1758 
  will 
  

   ascribe 
  the 
  genus 
  ^stoc»s 
  to 
  Grouovius, 
  1764 
  (Zoophylacium 
  Gronovianum, 
  Fascic- 
  

   ulus 
  II, 
  p. 
  227). 
  Even 
  as 
  early 
  as 
  1760Gronovius 
  (Acta 
  Helvetica, 
  IV, 
  p. 
  23) 
  assigned 
  

   <>alatea 
  slr'ujosa 
  polynomiallj^ 
  to 
  Astacus, 
  using 
  Astacus 
  in 
  its 
  old 
  pre-Liumean 
  sense. 
  

   In 
  1772 
  Pallas, 
  a 
  binomialist, 
  in 
  his 
  "Spicilegia 
  Zoologiea," 
  Fasciculus 
  IX, 
  p. 
  81, 
  used 
  

   the 
  combination 
  Astacus 
  dauuricus 
  in 
  treating 
  of 
  the 
  Daurian 
  crayfish. 
  Pallas 
  "wrote 
  

   in 
  Latin, 
  and 
  it 
  is 
  evident 
  that 
  Astacus 
  was 
  here 
  used 
  merely 
  as 
  the 
  Latin 
  word 
  for 
  

   "crayfish"or 
  "lobster," 
  andnotasa 
  technical 
  generic 
  name; 
  for 
  the 
  diagnosis 
  of 
  the 
  

   Daurian 
  crayfish 
  is 
  headed 
  " 
  Descriptio 
  Cancrl 
  daunrici," 
  conformably 
  with 
  Liuna-ns's 
  

   nomenclature. 
  Even 
  if 
  one 
  forces 
  the 
  point 
  and 
  carries 
  the 
  genus 
  Astacus 
  back 
  to 
  

   Pallas, 
  1772, 
  it 
  will 
  not 
  make 
  the 
  Daurian 
  crayfish 
  the 
  type 
  of 
  the 
  genus, 
  since 
  the 
  

   description 
  of 
  the 
  Daurian 
  crjiyfish 
  is 
  a 
  comparative 
  one, 
  the 
  lesser 
  European 
  .l.s.'a- 
  

   cus 
  [Astacus 
  nostras 
  minor~\, 
  i. 
  e.. 
  Cancer 
  astacus 
  Linnanis, 
  serving 
  as 
  the 
  standard 
  for 
  

   com])arison. 
  To 
  regard 
  as 
  a 
  typo 
  the 
  thing 
  compared, 
  rather 
  than 
  the 
  standard 
  of 
  

   comparison, 
  would 
  be 
  a 
  manifest 
  absurdity. 
  

  

  -Syst. 
  Eut., 
  1775. 
  

  

  ■'Species 
  Insectorum. 
  

  

  ■•Suppl. 
  Ent. 
  Syst. 
  

  

  f' 
  Considerations 
  Genf^rales 
  sur 
  I'Ordre 
  Naturel 
  des 
  Animaux 
  composaut 
  les 
  Classes 
  

   des 
  Crustacds, 
  des 
  Arachni<les, 
  et 
  des 
  Insectes. 
  

  

  