﻿NO. 
  1136. 
  OBSERVATIONS 
  ON 
  THE 
  ASTACIDJE— 
  FAXON. 
  687 
  

  

  row 
  of 
  confluescent 
  pits, 
  outer 
  face 
  with 
  a 
  longitudinal 
  furrow 
  just 
  

   below 
  the 
  superior 
  margiu 
  ; 
  cutting 
  edges 
  of 
  the 
  fingers 
  armed 
  with 
  a 
  

   few 
  blunt 
  teeth 
  near 
  the 
  proximal 
  end. 
  The 
  inner 
  branch 
  of 
  the 
  last 
  

   pair 
  of 
  abdominal 
  appendages 
  bears 
  a 
  longitudinal 
  median 
  rib, 
  which 
  

   runs 
  nearly 
  to 
  the 
  posterior 
  margin 
  of 
  the 
  segment, 
  but 
  this 
  rib 
  does 
  

   not 
  end 
  in 
  a 
  spine 
  as 
  it 
  usually 
  does 
  in 
  the 
  crayfishes. 
  

  

  Length 
  47 
  mm. 
  ; 
  length 
  of 
  carapace 
  23.5 
  mm. 
  ; 
  from 
  tip 
  of 
  rostrum 
  

   to 
  cervical 
  groove 
  15 
  mm.; 
  from 
  cervical 
  groove 
  to 
  hind 
  border 
  of 
  

   carapace 
  9.3 
  mm.; 
  breadth 
  of 
  areola 
  1,75 
  mm.; 
  length 
  of 
  cheliped 
  31 
  

   mm.; 
  length 
  of 
  merus 
  9 
  mm.; 
  length 
  of 
  carpus 
  mm.; 
  breadth 
  of 
  

   carpus 
  G 
  mm.; 
  length 
  of 
  chela 
  13,5 
  ram.; 
  breadth 
  of 
  chela 
  8 
  mm.; 
  

   superior 
  margin 
  of 
  propodite 
  (5,2 
  mm.; 
  length 
  of 
  dactylus 
  8 
  mm. 
  

  

  i^,7>,7rt^._Montevideo, 
  Uruguay. 
  W. 
  E. 
  Safford, 
  U. 
  S. 
  S. 
  '^ 
  Vandalia." 
  

   (Coll. 
  U.S.^^.M.) 
  Three 
  specimens. 
  Taken, 
  together 
  with 
  P. 
  safordi, 
  

   in 
  burrows 
  two 
  meters 
  deep, 
  one 
  hundred 
  meters 
  from 
  the 
  coast, 
  in 
  

   strata 
  of 
  sand 
  covered 
  by 
  soil. 
  

  

  Parasfacu.s 
  defo.s.sus 
  is 
  a 
  species 
  whose 
  appearance 
  clearly 
  reveals 
  its 
  

   subterranean 
  mode 
  of 
  life, 
  like 
  Camhanis 
  diogenes 
  of 
  the 
  United 
  States 
  

   and 
  the 
  so 
  called 
  Engwi 
  of 
  Tasmania, 
  It 
  has 
  some 
  affinity 
  with 
  P. 
  

   brasilieiisi.s 
  of 
  southern 
  Brazil, 
  a 
  species 
  not 
  especially 
  fossorial 
  in 
  

   habit, 
  but 
  found 
  in 
  brooks 
  and 
  springs. 
  P. 
  defossus 
  is 
  easily 
  distin- 
  

   guished 
  from 
  P. 
  brasiliensis 
  by 
  the 
  extreme 
  lateral 
  compression 
  of 
  the 
  

   cephalo-thorax, 
  the 
  small 
  size 
  of 
  the 
  anterior 
  end 
  of 
  the 
  abdomen, 
  the 
  

   strong 
  convergence 
  of 
  the 
  lateral 
  margins 
  of 
  the 
  rostrum, 
  the 
  length 
  

   and 
  narrowness 
  of 
  the 
  areola, 
  the 
  shape 
  of 
  the 
  chela 
  (which 
  is 
  much 
  

   shorter 
  and 
  broader 
  than 
  in 
  P. 
  brasiliensis), 
  the 
  long 
  oval 
  outline 
  of 
  

   the 
  telson, 
  etc. 
  

  

  PARASTACUS 
  HASSLERI, 
  new 
  species. 
  

   (Plate 
  LXX, 
  figs. 
  1-3.) 
  

  

  Cephalo-thorax 
  narrow. 
  Rostrum 
  rather 
  short, 
  reaching 
  nearly 
  to 
  

   the 
  distal 
  end 
  of 
  the 
  second 
  segment 
  of 
  the 
  antennular 
  peduncle; 
  upper 
  

   surface 
  slightly 
  excavated, 
  with 
  raised, 
  toothless 
  margins 
  convergent 
  

   from 
  the 
  base 
  to 
  the 
  blunt 
  (sometimes 
  truncate) 
  extremity. 
  Postorbital 
  

   ridges 
  slightly 
  marked, 
  strongly 
  divergent 
  from 
  before 
  backward, 
  not 
  

   confluent 
  witli 
  the 
  margins 
  of 
  the 
  rostrum, 
  inflated 
  at 
  the 
  posterior 
  end 
  

   so 
  as 
  to 
  form 
  a 
  low 
  tubercle. 
  Wall 
  of 
  the 
  orbit 
  produced 
  to 
  form 
  a 
  j)rom- 
  

   inent 
  angle 
  under 
  the 
  eye, 
  but 
  not 
  armed 
  with 
  a 
  spine. 
  Dorsal 
  surftice 
  

   of 
  carapace 
  smooth, 
  polished, 
  nearly 
  free 
  from 
  impressed 
  dots 
  over 
  the 
  

   gastric 
  area, 
  areola 
  rather 
  narrow, 
  its 
  field 
  thickly 
  strewn 
  with 
  im- 
  

   pressed 
  dots; 
  a 
  group 
  of 
  six 
  to 
  nine 
  small, 
  blunt 
  tubercles 
  on 
  the 
  ante- 
  

   rior 
  part 
  of 
  the 
  lateral 
  walls 
  of 
  the 
  carapace; 
  branchial 
  regions 
  lightly 
  

   granular. 
  Distance 
  from 
  tip 
  of 
  rostrum 
  to 
  cervical 
  groove 
  about 
  twice 
  

   the 
  length 
  of 
  the 
  areola. 
  Abdominal 
  pleura^ 
  rounded. 
  Ilind 
  border 
  

   of 
  telsoQ 
  rounded, 
  lateral 
  spines 
  obsolescent. 
  Anterior 
  process 
  of 
  epis- 
  

  

  