﻿OBSERVATIONS 
  ON 
  THE 
  JSTACIDJ]:—FJXON. 
  691 
  

  

  with 
  scattered 
  setse; 
  margins 
  slightly 
  raised, 
  convergent, 
  lightly 
  con- 
  

   vex, 
  armed 
  near 
  the 
  tip 
  with 
  a 
  pair 
  of 
  small, 
  blunt 
  denticles; 
  acumen 
  

   short, 
  subacute. 
  Suborbital 
  angle 
  prominent, 
  but 
  rounded 
  off, 
  unarmed 
  

   with 
  tooth 
  or 
  spine. 
  Postocular 
  ridges 
  obsolete 
  except 
  their 
  anterior 
  

   ends, 
  whicli 
  form 
  a 
  tubercle 
  on 
  each' 
  side 
  of 
  the 
  base 
  of 
  the 
  rostrum 
  — 
  a 
  

   tubercle 
  channeled 
  along 
  its 
  outer 
  face 
  and 
  terminating 
  anteriorly 
  in 
  

   an 
  obsolescent 
  tooth. 
  Carapace 
  smooth 
  and 
  lightly 
  punctate 
  above, 
  

   minutely 
  granular 
  on 
  the 
  sides. 
  Cervical 
  groove 
  sinuous, 
  no 
  lateral 
  

   spine. 
  Areola 
  very 
  broad. 
  Distance 
  from 
  tip 
  of 
  rostrom 
  to 
  cervical 
  

   groove 
  upward 
  of 
  twice 
  and 
  a 
  half 
  as 
  long 
  as 
  the 
  areola. 
  Abdomen 
  

   smooth, 
  pleune 
  rounded. 
  Sides 
  of 
  telson 
  slightly 
  convergent, 
  armed 
  

   with 
  a 
  spine 
  on 
  each 
  side, 
  one-third 
  way 
  from 
  the 
  distal 
  end; 
  distal 
  

   border 
  truncate, 
  posterolateral 
  corners 
  rounded. 
  Anterior 
  process 
  of 
  

   the 
  epistome 
  triangular, 
  sides 
  straight 
  or 
  slightly 
  convex, 
  tip 
  blunt 
  or 
  

   slightly 
  truncate; 
  a 
  slight 
  furrow 
  divides 
  the 
  anterior 
  process 
  from 
  the 
  

   body 
  of 
  the 
  epistome, 
  and 
  the 
  latter 
  is 
  divided 
  in 
  halves 
  by 
  a 
  longi- 
  

   tudinal 
  depression. 
  Basal 
  segment 
  of 
  antenna 
  armed 
  with 
  a 
  sharp 
  

   spine 
  in 
  front 
  of 
  the 
  orifice 
  of 
  the 
  green 
  gland; 
  another 
  spine 
  lies 
  at 
  

   the 
  base 
  of 
  the 
  outer 
  edge 
  of 
  the 
  antennal 
  scale; 
  the 
  antennal 
  scale 
  is 
  

   of 
  moderate 
  size, 
  a 
  little 
  longer 
  than 
  the 
  rostrum, 
  broadest 
  near 
  the 
  

   middle, 
  its 
  outer 
  margin 
  slightly 
  convex, 
  ending 
  in 
  a 
  small 
  apical 
  spine. 
  

   Tliird 
  pair 
  of 
  maxillipeds 
  hairy 
  within 
  and 
  below. 
  Right 
  and 
  left 
  cheli- 
  

   peds 
  very 
  unequal, 
  the 
  left 
  usually 
  the 
  larger; 
  lower 
  margins 
  of 
  the 
  

   merus 
  denticulate, 
  upper 
  margin 
  furnished 
  with 
  one 
  small 
  tooth 
  near 
  

   the 
  distal 
  end 
  of 
  the 
  segment; 
  outer 
  and 
  inner 
  faces 
  smooth; 
  carpus 
  

   marked 
  with 
  a 
  conspicuous 
  longitudinal 
  groove 
  on 
  its 
  upjjer 
  outer 
  

   face, 
  and 
  with 
  a 
  few 
  small, 
  blunt 
  tubercles 
  on 
  its 
  inner 
  margin; 
  lower 
  

   external 
  border 
  of 
  carpus 
  short, 
  rounded, 
  and 
  protuberant; 
  chehe 
  with- 
  

   out 
  prominent 
  tubercles 
  or 
  spines, 
  but 
  when 
  viewed 
  under 
  a 
  lens 
  the 
  

   surface 
  is 
  finely 
  squamoso-tuberculate 
  proximally, 
  punctate 
  distally; 
  

   the 
  superior 
  and 
  inferior 
  borders 
  of 
  the 
  chela 
  are 
  rounded, 
  the 
  fingers 
  

   setose 
  along 
  their 
  cutting 
  edges; 
  the 
  fingers 
  of 
  the 
  left 
  (larger) 
  chela 
  

   are 
  stout, 
  somewhat 
  gaping, 
  with 
  one 
  evident 
  round 
  tubercle 
  on 
  the 
  

   prehensile 
  margin; 
  the 
  fingers 
  of 
  the 
  right 
  (smaller) 
  chela 
  are 
  rela- 
  

   tively 
  longer 
  and 
  slenderer 
  and 
  are 
  devoid 
  of 
  tubercles 
  on 
  the 
  prehen- 
  

   sile 
  margins. 
  The 
  median 
  longitudinal 
  ridge 
  on 
  the 
  inner 
  blade 
  of 
  

   the 
  last 
  abdominal 
  appendages 
  ends 
  in 
  a 
  small 
  spine 
  near 
  the 
  posterior 
  

   border. 
  

  

  Length 
  of 
  a 
  male 
  83 
  mm.; 
  cephalo-thorax 
  38 
  mm.; 
  abdomen 
  45 
  mm.; 
  

   length 
  of 
  rostrum 
  9 
  mm.; 
  width 
  of 
  rostrum 
  at 
  base 
  5 
  mm.; 
  length 
  of 
  

   telson 
  12 
  mm. 
  ; 
  width 
  of 
  telson 
  at 
  base 
  11 
  mm. 
  ; 
  from 
  tip 
  of 
  rostrum 
  

   to 
  cervical 
  groove 
  28 
  mm. 
  ; 
  from 
  cervical 
  groove 
  to 
  posterior 
  margin 
  

   of 
  carapace 
  10 
  mm.; 
  width 
  of 
  areola 
  8.8 
  mm.; 
  length 
  of 
  left 
  cheli- 
  

   ped 
  67 
  mm. 
  (merus 
  15 
  mm., 
  carpus 
  11 
  mm., 
  chela 
  32 
  by 
  16 
  mm., 
  

   dactylus 
  20 
  mm.); 
  length 
  of 
  right 
  cheliped 
  51 
  mm. 
  (merus 
  11 
  mm., 
  

   carpus 
  9 
  mm., 
  chela 
  25 
  by 
  8.5 
  mm., 
  dactylus 
  16 
  mm.). 
  

  

  The 
  largest 
  individual 
  (a 
  male) 
  is 
  97 
  mm. 
  long. 
  

  

  