﻿N0.1136. 
  OBSERVATIONS 
  ON 
  THE 
  J 
  STAC 
  ID 
  JE— 
  FAXON. 
  653 
  

  

  lected 
  at 
  Irondale, 
  and 
  in 
  Eeynolds 
  County, 
  Missouri.' 
  Both 
  in 
  the 
  

   shape 
  of 
  the 
  claw 
  s 
  and 
  in 
  the 
  character 
  of 
  the 
  male 
  appendages 
  the 
  

   Cabool 
  specimens 
  are 
  transitional 
  forms 
  connecting 
  C. 
  virilis 
  with 
  C. 
  

   rusticus 
  and 
  allied 
  species. 
  

  

  CAMBARUS 
  LONGIDIGITUS, 
  new 
  species. 
  

   (Plate 
  LXII, 
  figs. 
  6-9.) 
  

  

  BoTsal 
  surface 
  of 
  the 
  carapace 
  flattened, 
  thickly 
  and 
  coarsely 
  punc- 
  

   tate; 
  lateral 
  walls 
  granulate. 
  Rostrum 
  long, 
  concave 
  above, 
  sides 
  par- 
  

   allel 
  from 
  base 
  to 
  tbe 
  lateral 
  pair 
  of 
  spines, 
  which 
  are 
  sharp 
  and 
  directed 
  

   forward; 
  acumen 
  long, 
  acute, 
  reaching 
  to 
  the 
  distal 
  extremity 
  of 
  the 
  

   anteuuular 
  peduncle, 
  and 
  to 
  the 
  middle 
  of 
  the 
  distal 
  segment 
  of 
  

   the 
  antennal 
  peduncle. 
  Postorbital 
  ridges 
  curved 
  inward 
  at 
  the 
  pos- 
  

   terior 
  end, 
  armed 
  at 
  the 
  anterior 
  end 
  with 
  a 
  sharp 
  spine. 
  Antero- 
  

   lateral 
  margin 
  of 
  carapace 
  bluntly 
  angulated 
  beneath 
  the 
  orbit, 
  but 
  

   not 
  armed 
  with 
  a 
  si)ine. 
  There 
  is 
  a 
  prominent 
  spine 
  on 
  each 
  side 
  of 
  

   the 
  carapace 
  on 
  the 
  hinder 
  border 
  of 
  the 
  cervical 
  groove; 
  a 
  small 
  

   branchiostegian 
  spine 
  is 
  also 
  present. 
  The 
  areola 
  is 
  very 
  narrow 
  for 
  

   the 
  greater 
  part 
  of 
  its 
  length 
  ; 
  its 
  narrowest 
  part 
  is 
  well 
  forward, 
  close 
  

   to 
  the 
  small, 
  but 
  broad, 
  triangular 
  field 
  that 
  borders 
  upon 
  the 
  cervical 
  

   groove; 
  from 
  this 
  point 
  it 
  widens 
  gradually 
  and 
  slightly 
  to 
  the 
  hinder 
  

   end. 
  

  

  The 
  abdomen 
  presents 
  no 
  distinctive 
  characters; 
  the 
  pleuniB 
  are 
  

   l)unctate, 
  their 
  j)ostero-lateral 
  angles 
  rounded. 
  The 
  telson 
  is 
  rather 
  

   long, 
  armed 
  with 
  a 
  pair 
  of 
  spines 
  on 
  each 
  side 
  of 
  the 
  transverse 
  suture; 
  

   its 
  hind 
  margin 
  truncate. 
  

  

  The 
  anterior 
  i)rocess 
  of 
  the 
  epistome 
  is 
  broadly 
  triangular, 
  its 
  autero- 
  

   lateral 
  margins 
  slightly 
  convex, 
  its 
  anterior 
  angle 
  rounded, 
  truncate, 
  

   or 
  (in 
  a 
  few 
  examples) 
  slightly 
  notched. 
  The 
  basal 
  segment 
  of 
  the 
  

   antenna 
  bears 
  no 
  spine, 
  but 
  the 
  so-called 
  olfactory 
  turbercle 
  is 
  ])romi- 
  

   nent 
  just 
  in 
  front 
  of 
  the 
  orifice 
  of 
  the 
  green 
  gland; 
  the 
  second 
  seg- 
  

   ment 
  of 
  the 
  antenna 
  is 
  armed 
  with 
  a 
  small 
  but 
  sharp 
  lateral 
  spine. 
  

   The 
  antennal 
  scales 
  are 
  about 
  as 
  long 
  as 
  the 
  rostrum, 
  of 
  moderate 
  

   width, 
  widest 
  at 
  the 
  middle. 
  

  

  The 
  merus 
  of 
  the 
  chelipeds 
  is 
  armed, 
  as 
  usual, 
  with 
  spines 
  bise- 
  

   rially 
  disposed 
  on 
  the 
  inferior 
  margins, 
  and 
  with 
  two 
  obliquely 
  placed 
  

   spines 
  on 
  the 
  superior 
  border 
  near 
  the 
  distal 
  end; 
  the 
  carpus 
  is 
  longi- 
  

   tudinally 
  furrowed, 
  punctate, 
  and 
  slightly 
  tuberculate 
  above; 
  there 
  

   is 
  a 
  small 
  spine 
  near 
  each 
  point 
  of 
  articulation 
  with 
  the 
  manus, 
  two 
  

   spines 
  besides 
  on 
  the 
  inner 
  border 
  — 
  one 
  median 
  and 
  one 
  smaller 
  one 
  

   near 
  the 
  posterior 
  end 
  of 
  the 
  segment; 
  the 
  lower 
  surfiice 
  presents, 
  

   moreover, 
  a 
  prominent 
  acute 
  median 
  spine 
  together 
  with 
  a 
  minute 
  

   spinule 
  lying 
  between 
  the 
  inferior 
  median 
  and 
  the 
  internal 
  median 
  

   sjDines 
  (the 
  smaller 
  spinule 
  is 
  sometimes 
  obsolete). 
  The 
  jialm, 
  or 
  basal 
  

   part 
  of 
  the 
  propodite, 
  is 
  flattened 
  and 
  very 
  short; 
  its 
  upper 
  face 
  is 
  

  

  1 
  Hev. 
  Astacidse, 
  p. 
  98, 
  and 
  Proc. 
  U. 
  S. 
  Nat, 
  Mus., 
  XII, 
  p. 
  630. 
  

  

  