﻿660 
  niOCEEDIXGS 
  OF 
  lUE 
  NATIONAL 
  MUSEUM. 
  vol.xx. 
  

  

  the 
  greater 
  length 
  of 
  the 
  section 
  of 
  the 
  carapace 
  behind 
  the 
  cervical 
  

   groove, 
  and 
  its 
  shorter, 
  more 
  tapering, 
  and 
  carinated 
  rostrum. 
  All 
  of 
  

   these 
  characters, 
  with 
  the 
  exception 
  of 
  the 
  carination 
  of 
  the 
  rostrum, 
  

   also 
  serve 
  to 
  separate 
  C.projyinquus 
  sanbornii 
  from 
  the 
  present 
  species. 
  

   The 
  habitat 
  of 
  C. 
  erichsonianus^ 
  eastern 
  Tennessee 
  and 
  northern 
  

   Alabama, 
  is 
  closely 
  adjacent 
  to 
  that 
  of 
  C. 
  fipiiiosiis. 
  G. 
  propiiuinua 
  is 
  a 
  

   more 
  northern 
  form, 
  unknown 
  south 
  of 
  the 
  Ohio. 
  C. 
  proplnfiuus 
  

   sanhornii 
  has 
  been 
  found 
  in 
  Kentucky 
  and 
  Ohio. 
  

  

  CAMBARUS 
  FORCEPS 
  Faxon. 
  

  

  Clinch 
  River 
  at 
  Walker's 
  Ford, 
  eleven 
  miles 
  northwest 
  of 
  Tazewell, 
  

   Tennessee; 
  Bull's 
  (or 
  Big 
  Sycamore) 
  Creek, 
  tributary 
  of 
  Clinch 
  Kiver, 
  

   seven 
  miles 
  south 
  of 
  Tazewell, 
  Tennessee. 
  (Coll.U.S.K.M.) 
  

  

  GROUP 
  V. 
  (Type, 
  Cambarns 
  montezuma; 
  Snnsanre.) 
  

  

  Third 
  segment 
  of 
  second 
  and 
  third 
  pairs 
  of 
  legs 
  of 
  male 
  hooked. 
  

   First 
  abdominal 
  appendages 
  similar 
  to 
  those 
  of 
  Group 
  IV. 
  

  

  CAMBARUS 
  MONTEZUMiE 
  Saussure. 
  

  

  The 
  tyi)ical 
  form 
  of 
  C. 
  montezuma' 
  comes 
  from 
  the 
  plain 
  of 
  the 
  City 
  

   of 
  Mexico. 
  It 
  has 
  also 
  been 
  recorded 
  from 
  Puebla' 
  and 
  from 
  Vera 
  

   Cruz.- 
  The 
  Puebla 
  specimens 
  (var. 
  tridens 
  von 
  Martens) 
  are 
  described 
  

   as 
  having 
  a 
  pair 
  of 
  small 
  lateral 
  teeth 
  near 
  the 
  apex 
  of 
  the 
  rostrum, 
  

   but 
  this 
  is 
  also 
  true 
  of 
  many 
  of 
  the 
  specimens, 
  especially 
  the 
  second 
  

   form 
  males 
  and 
  the 
  females, 
  from 
  the 
  type 
  locality. 
  In 
  the 
  typical 
  form 
  

   the 
  rostrum 
  is 
  smooth 
  and 
  lightly 
  hollowed 
  out 
  above, 
  the 
  sides 
  of 
  the 
  

   rostrum 
  are 
  nearly 
  jiarallel 
  (but 
  slightly 
  convex) 
  from 
  the 
  base 
  to 
  the 
  

   proximal 
  end 
  of 
  the 
  acumen, 
  which 
  is 
  short 
  (not 
  surpassing 
  the 
  second 
  

   antennular 
  segment) 
  and 
  flanked 
  by 
  very 
  small 
  lateral 
  teeth 
  (often 
  

   obsolete). 
  The 
  postorbital 
  ridges 
  are 
  unarmed, 
  or 
  furnished 
  at 
  the 
  most 
  

   with 
  the 
  merest 
  vestige 
  of 
  the 
  anterior 
  sjjines. 
  The 
  portion 
  of 
  the 
  

   carapace 
  posterior 
  to 
  the 
  cervical 
  groove 
  is 
  much 
  more 
  than 
  half 
  the 
  

   distance 
  from 
  the 
  groove 
  to 
  the 
  anterior 
  extremity 
  of 
  the 
  rostrum. 
  

  

  CAMBARUS 
  MONTEZUMiE 
  DUGESII, 
  new 
  subspecies. 
  

  

  (Plate 
  LXYI, 
  fig. 
  1. 
  ) 
  

  

  Cambarus 
  monUzuma' 
  Faxon, 
  Proc. 
  U. 
  S. 
  Nat. 
  Miis., 
  XII, 
  1889, 
  p. 
  633. 
  

  

  Differs 
  from 
  C. 
  montezuma' 
  as 
  follows: 
  The 
  upper 
  surface 
  of 
  the 
  

   rostrum 
  is 
  i)erfectly 
  flat, 
  except 
  for 
  tbe 
  margins, 
  which 
  are 
  raised 
  so 
  as 
  

   to 
  form 
  lateral 
  carinse; 
  the 
  sides 
  of 
  the 
  rostrum 
  converge 
  from 
  the 
  

   base 
  to 
  the 
  proximal 
  end 
  of 
  the 
  acumen, 
  which 
  is 
  slenderer 
  and 
  a 
  little 
  

   longer 
  than 
  in 
  C. 
  montezuma'; 
  the 
  lateral 
  teeth 
  of 
  the 
  rostrum 
  are 
  

  

  1 
  Von 
  Martens, 
  Arch. 
  f. 
  Naturgcsch., 
  38ter 
  Jahrg., 
  1872, 
  I, 
  p. 
  130. 
  

   •■^Ortiuauu, 
  Zooloy. 
  Jahrb., 
  Abtb. 
  f. 
  Sy^t., 
  VI, 
  1891, 
  p. 
  12. 
  

  

  