﻿NO. 
  1950. 
  CRUSTACEAN 
  PARASITES 
  OF 
  FISH 
  AND 
  CRABS— 
  WILSON. 
  229 
  

  

  Total 
  length, 
  8 
  to 
  9 
  nini. 
  Cephalothorax, 
  2 
  mm. 
  long, 
  1.6 
  mm. 
  

   wide. 
  Thorax, 
  5 
  mm. 
  long, 
  3.6 
  mm. 
  wide. 
  Egg-strings, 
  18 
  to 
  20 
  

   mm. 
  long. 
  > 
  

  

  Male. 
  — 
  General 
  body 
  shape 
  elongate 
  and 
  narrow; 
  cephalothorax 
  

   ovate, 
  with 
  a 
  squarely 
  truncated 
  frontal 
  margin. 
  Antennal 
  area 
  sep- 
  

   arated 
  from 
  the 
  rest 
  of 
  the 
  head 
  by 
  a 
  well-defined 
  groove 
  as 
  in 
  the 
  

   female. 
  Posterior 
  body 
  spindle-shaped, 
  the 
  same 
  width 
  as 
  the 
  ceph- 
  

   alothorax, 
  but 
  half 
  as 
  long 
  again, 
  with 
  the 
  free 
  thorax, 
  genital 
  segment 
  

   and 
  abdomen 
  thoroughly 
  fused. 
  

  

  First 
  antennge 
  relatively 
  much 
  longer 
  than 
  in 
  the 
  female 
  and 
  pro- 
  

   jecting 
  prominently 
  from 
  the 
  anterior 
  corners 
  of 
  the 
  cephalothorax. 
  

   Second 
  pair 
  very 
  stout, 
  the 
  basal 
  joint 
  swollen, 
  supported 
  on 
  a 
  com- 
  

   plex 
  cliitin 
  framework, 
  and 
  armed 
  on 
  the 
  inner 
  margin 
  near 
  the 
  prox- 
  

   imal 
  end 
  with 
  a 
  short 
  tooth. 
  Mouth 
  parts 
  as 
  in 
  the 
  female, 
  the 
  basal 
  

   joint 
  of 
  the 
  maxilliped 
  being 
  considerably 
  stouter. 
  First 
  legs 
  with 
  

   minute 
  one-jointed 
  rami, 
  the 
  endopod 
  with 
  one 
  spine 
  longer 
  than 
  the 
  

   ramus 
  itself, 
  and 
  a 
  second 
  much 
  shorter 
  one, 
  the 
  exopod 
  with 
  four 
  

   short 
  saw 
  teeth. 
  

  

  Endopod 
  of 
  second 
  legs 
  tipped 
  with 
  a 
  single 
  large 
  spine 
  the 
  same 
  

   length 
  as 
  the 
  ramus; 
  exopod 
  enlarged 
  toward 
  the 
  tip, 
  where 
  it 
  carries 
  

   two 
  minute 
  spines 
  interspersed 
  with 
  a 
  row 
  of 
  short 
  hairs. 
  Third 
  legs 
  

   with 
  a 
  short 
  basal 
  portion, 
  an 
  exopod 
  two-thirds 
  as 
  long 
  as 
  the 
  entire 
  

   body, 
  and 
  an 
  endopod 
  reduced 
  to 
  a 
  mere 
  knob 
  on 
  the 
  inner 
  margin 
  

   of 
  the 
  basal 
  portion 
  at 
  its 
  tip. 
  

  

  Fourth 
  legs 
  as 
  long 
  as 
  the 
  entire 
  body, 
  basal 
  portion 
  projecting 
  well 
  

   beyond 
  the 
  lateral 
  marguis; 
  rami 
  about 
  the 
  same 
  size 
  and 
  length. 
  

  

  Total 
  length, 
  not 
  including 
  the 
  legs, 
  2.75 
  mm.; 
  including 
  the 
  legs, 
  

   4 
  mm. 
  Cephalothorax, 
  0.95 
  mm. 
  long, 
  0.75 
  mm. 
  wide. 
  Posterior 
  

   body, 
  0.75 
  mm. 
  wide, 
  1.8 
  mm. 
  long. 
  Fourth 
  legs, 
  2.5 
  mm. 
  long. 
  

  

  Color 
  of 
  both 
  sexes, 
  a 
  dark 
  yellowish-gray, 
  without 
  pigment 
  mark- 
  

   ings 
  of 
  any 
  sort. 
  

  

  (giganteus, 
  of 
  large 
  size.) 
  

  

  Hitherto 
  there 
  have 
  been 
  but 
  two 
  descriptions 
  of 
  this 
  species, 
  both 
  

   made 
  from 
  the 
  same 
  (single) 
  female; 
  to 
  these 
  is 
  now 
  added 
  the 
  pres- 
  

   ent 
  description 
  and 
  drawings 
  from 
  an 
  abundance 
  of 
  living 
  material, 
  

   taken 
  on 
  new 
  hosts 
  and 
  in 
  a 
  different 
  locality 
  and 
  including 
  for 
  the 
  

   first 
  time 
  the 
  male 
  sex. 
  We 
  thus 
  get 
  acquainted 
  with 
  the 
  variations 
  

   m 
  size 
  and 
  structure 
  and 
  the 
  relative 
  proportions 
  of 
  the 
  male. 
  

  

  The 
  species 
  is 
  readily 
  distinguished 
  by 
  its 
  size, 
  b}^ 
  the 
  narrow 
  ceph- 
  

   alothorax 
  with 
  its 
  sides 
  projecting 
  in 
  front 
  of 
  the 
  anterior 
  margin, 
  by 
  

   the 
  short 
  projections 
  of 
  the 
  dorsal 
  shield 
  opposite 
  the 
  bases 
  of 
  the 
  

   third 
  legs, 
  by 
  the 
  very 
  long 
  and 
  narrow 
  fourth 
  legs, 
  which 
  reach 
  far 
  

   behind 
  the 
  dorsal 
  shield 
  of 
  the 
  fourth 
  segment, 
  and 
  by 
  the 
  thread- 
  

   like 
  fifth 
  legs, 
  curved 
  like 
  parenthesis 
  marks. 
  The 
  species 
  is 
  still 
  

   among 
  the 
  largest 
  in 
  the 
  genus 
  and 
  is 
  one 
  of 
  the 
  few 
  instances 
  where 
  

   the 
  original 
  "giant" 
  has 
  retained 
  its 
  prestige. 
  

  

  