﻿654 
  PBOCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  

  

  coarsely 
  punctate 
  and 
  armed 
  along- 
  its 
  inner 
  border 
  witli 
  a 
  double 
  

   row 
  of 
  spiniforni 
  tubercles. 
  The 
  lingers 
  are 
  excessively 
  long, 
  the 
  

   dactylus 
  being 
  more 
  than 
  three 
  times 
  as 
  long 
  as 
  the 
  inner 
  margin 
  

   of 
  the 
  i)abn; 
  the 
  fingers 
  meet 
  only 
  at 
  their 
  tips, 
  which 
  cross 
  each 
  

   other; 
  the 
  grasping 
  edges 
  of 
  both 
  fingers 
  are 
  furnished 
  with 
  blunt 
  

   teeth, 
  irregular 
  in 
  size, 
  while 
  the 
  opposite 
  margin 
  (or 
  margin 
  toward 
  

   the 
  median 
  line 
  of 
  the 
  body) 
  of 
  the 
  dactylus 
  is 
  armed 
  with 
  two 
  longi 
  

   tudinal 
  rows 
  of 
  acute 
  teeth. 
  The 
  external 
  finger 
  is 
  barbate 
  within 
  at 
  

   the 
  base. 
  

  

  The 
  first 
  abdominal 
  appendages 
  of 
  the 
  second 
  form 
  of 
  the 
  male 
  are 
  

   long 
  and 
  slender, 
  their 
  tips 
  lying 
  between 
  the 
  second 
  pair 
  of 
  legs 
  

   wheu 
  directed 
  forward. 
  The 
  outer 
  branch 
  is 
  longer 
  than 
  the 
  inner 
  

   branch. 
  The 
  tips 
  of 
  both 
  branches 
  are 
  distinctly 
  recurved. 
  

  

  The 
  annulus 
  veutralis 
  of 
  the 
  female 
  is 
  triangular, 
  with 
  a 
  deep 
  trans- 
  

   verse 
  central 
  fossa. 
  The 
  anterior 
  wall 
  is 
  indistinctly 
  bituberculate, 
  

   the 
  posterior 
  wall 
  thickened 
  and 
  divided 
  by 
  a 
  median 
  longitudinal 
  

   sigmoid 
  closed 
  fissure. 
  The 
  claws 
  of 
  the 
  female 
  do 
  not 
  differ 
  in 
  form 
  

   from 
  those 
  of 
  the 
  male. 
  

  

  Dimensions 
  of 
  a 
  male, 
  Form 
  II: 
  Length 
  81 
  mm.; 
  length 
  of 
  carapace 
  

   41 
  mm.; 
  length 
  of 
  rostrum 
  13 
  mm., 
  width 
  of 
  rostrum 
  4.5 
  mm.; 
  length 
  

   of 
  rostral 
  acumen 
  G 
  mm.; 
  distance 
  from 
  tip 
  of 
  rostrum 
  to 
  cervical 
  

   groove 
  28 
  mm. 
  ; 
  distance 
  from 
  cervical 
  groove 
  to 
  posterior 
  border 
  of 
  

   carapace 
  13 
  mm.; 
  width 
  of 
  areola 
  at 
  its 
  Jiarrowest 
  0.5 
  mm.; 
  length 
  of 
  

   cheliped 
  07.5 
  mm.; 
  length 
  of 
  nierus 
  15.5 
  mm.; 
  length 
  of 
  carpus 
  10 
  

   mm.; 
  length 
  of 
  chela 
  35 
  mm.; 
  breadth 
  of 
  chela 
  10.5 
  mm.; 
  inner 
  mar- 
  

   gin 
  of 
  palm 
  8 
  mm.; 
  length 
  of 
  dactylus 
  25.5 
  mm. 
  

  

  The 
  largest 
  specimen 
  (a 
  female) 
  is 
  101 
  mm. 
  long; 
  the 
  large 
  claw 
  

   measures 
  47.5 
  mm. 
  in 
  length, 
  the 
  dactylus 
  36 
  mm. 
  

  

  Oxford 
  Bend, 
  White 
  Eiver, 
  Arkansas. 
  (Coll. 
  Mus. 
  Comp. 
  Zool.) 
  Four 
  

   males, 
  Form 
  II; 
  four 
  females, 
  six 
  young. 
  

  

  This 
  clearly 
  characterized 
  species, 
  discovered 
  by 
  Professor 
  S. 
  E. 
  

   Meek, 
  is 
  related 
  to 
  C. 
  virilis, 
  with 
  which 
  it 
  agrees 
  essentially 
  in 
  the 
  

   form 
  of 
  the 
  sexual 
  ]>arts, 
  both 
  male 
  and 
  female, 
  and 
  the 
  areola. 
  It 
  is 
  

   readily 
  distinguished 
  from 
  G. 
  virilis 
  by 
  its 
  longer, 
  parallel-sided 
  ros- 
  

   trum, 
  with 
  longer 
  lateral 
  spines 
  and 
  acumen, 
  as 
  well 
  as 
  by 
  the 
  excessive 
  

   length 
  and 
  slenderness 
  of 
  the 
  fingers. 
  In 
  many 
  individuals 
  the 
  chehv. 
  

   are 
  unequal 
  in 
  size 
  on 
  the 
  right 
  and 
  left 
  sides, 
  the 
  right 
  being 
  com- 
  

   monly 
  the 
  larger. 
  

  

  In 
  recent 
  alcoholic 
  specimens 
  the 
  fingers 
  are 
  clouded 
  with 
  dusky, 
  and 
  

   a 
  large 
  spot 
  or 
  blotch 
  of 
  the 
  same 
  hue 
  is 
  seen 
  ou 
  both 
  sides 
  of 
  the 
  hand 
  

   near 
  the 
  articulation 
  with 
  the 
  wrist. 
  

  

  CAMBARUS 
  IMMUNIS 
  Hagen. 
  

  

  Small 
  stream 
  llowing 
  into 
  Oneida 
  Lake, 
  Xew 
  York 
  (No. 
  4330, 
  Mus. 
  

   Comi). 
  Zool.). 
  Sandusky, 
  Erie 
  County, 
  Ohio 
  (Xo. 
  5038, 
  Mus. 
  Comp. 
  

   Zool.). 
  Northern 
  Ohio, 
  near 
  shore 
  of 
  Lake 
  Erie; 
  Ames, 
  Story 
  County, 
  

   Iowa; 
  South 
  Bend, 
  Cass 
  County, 
  Nebraska 
  (Coll. 
  U.S.N.M.). 
  Also 
  

  

  