﻿NO. 
  1950. 
  CRUSTACEAX 
  PARASITES 
  OF 
  FISH 
  AXD 
  CRABS— 
  WILSOX. 
  197 
  

  

  joint 
  and 
  a 
  rather 
  slender, 
  strongly 
  curved 
  terminal 
  claw, 
  with 
  a 
  

   long 
  accessory 
  spine 
  at 
  the 
  posterior 
  curve 
  of 
  the 
  S. 
  

  

  First 
  summing 
  legs 
  with 
  a 
  two-jointed 
  exopod 
  and 
  a 
  three-jointed 
  

   endopod, 
  the 
  remaining 
  legs 
  with 
  three-jointed 
  rami, 
  the 
  arrange- 
  

   ment 
  of 
  the 
  spines 
  and 
  setae 
  as 
  follows: 
  Second 
  exopod, 
  I 
  — 
  0, 
  I 
  — 
  1, 
  

   II— 
  5; 
  endopod, 
  0—1, 
  0—2, 
  II— 
  3. 
  Third 
  exopod, 
  I— 
  0, 
  I— 
  1, 
  

   III— 
  5; 
  endopod, 
  I— 
  1, 
  1—2, 
  1—3. 
  Fourth 
  exopod, 
  1—0, 
  I— 
  1, 
  

   II 
  — 
  5; 
  endopod, 
  — 
  1, 
  — 
  1, 
  I 
  — 
  2. 
  Fifth 
  legs 
  two-jointed, 
  the 
  basal 
  

   joint 
  much 
  shorter 
  than 
  the 
  termmal 
  and 
  at 
  an 
  angle 
  with 
  the 
  latter, 
  

   which 
  is 
  tipped 
  with 
  three 
  spines 
  of 
  equal 
  length. 
  

  

  Color 
  a 
  translucent 
  cartilage 
  gray, 
  the 
  ovaries, 
  oviducts, 
  and 
  ex- 
  

   ternal 
  egg-cases 
  white. 
  

  

  Total 
  length, 
  2.45 
  mm. 
  Carapace, 
  0.65 
  mm. 
  long, 
  1.3 
  mm. 
  wide. 
  

   Free 
  segments, 
  1 
  mm. 
  long. 
  Egg-strings, 
  1.45 
  mm. 
  long. 
  

  

  Male. 
  — 
  General 
  body 
  form 
  wider 
  than 
  usual; 
  carapace 
  trans- 
  

   versely 
  elhptical, 
  one-half 
  Avider 
  than 
  long, 
  forming 
  a 
  blunt 
  point 
  on 
  

   each 
  lateral 
  and 
  on 
  the 
  frontal 
  margin. 
  Second, 
  third, 
  fourth, 
  and 
  

   fifth 
  thorax 
  segments 
  the 
  same 
  length 
  but 
  diminishing 
  regularly 
  in 
  

   "width, 
  and 
  leaving 
  the 
  whole 
  of 
  the 
  swimming 
  legs 
  visible 
  in 
  dorsal 
  

   view. 
  Genital 
  segment 
  the 
  same 
  wddth 
  as 
  the 
  fourth 
  segment, 
  

   elongate 
  acorn-shaped, 
  with 
  a 
  squarely 
  truncated 
  posterior 
  border 
  

   and 
  prominent 
  well-rounded 
  posterior 
  corners. 
  

  

  Abdomen 
  half 
  the 
  width 
  of 
  the 
  genital 
  segment 
  and 
  much 
  shorter, 
  

   two-jointed, 
  the 
  joints 
  equal; 
  anal 
  laminae 
  quadrilateral, 
  a 
  little 
  longer 
  

   than 
  wide 
  and 
  armed 
  as 
  in 
  the 
  female. 
  

  

  Basal 
  portion 
  of 
  the 
  first 
  antennae 
  narrower 
  and 
  straighter 
  than 
  in 
  

   the 
  female; 
  second 
  antennae 
  and 
  mouth 
  parts 
  the 
  same 
  except 
  the 
  

   maxillipeds. 
  These 
  are 
  in 
  normal 
  position 
  behind 
  the 
  other 
  mouth 
  

   parts 
  and 
  are 
  three-jointed; 
  the 
  second 
  joint 
  is 
  stout 
  with 
  its 
  posterior 
  

   margin 
  swollen 
  into 
  a 
  pad 
  entirely 
  covered 
  with 
  short 
  spines 
  which 
  

   increase 
  in 
  size 
  toward 
  the 
  distal 
  end; 
  the 
  terminal 
  claw 
  is 
  slender, 
  

   three-fourths 
  the 
  length 
  of 
  the 
  second 
  joint, 
  slightly 
  curved, 
  and 
  

   armed 
  along 
  its 
  umer 
  margin 
  with 
  a 
  row 
  of 
  minute 
  saw 
  teeth, 
  which 
  

   shut 
  down 
  against 
  the 
  spiny 
  pad 
  on 
  the 
  second 
  joint. 
  

  

  S\\imming 
  legs 
  jointed 
  as 
  in 
  the 
  female 
  but 
  quite 
  differently 
  armed; 
  

   the 
  basal 
  exopod 
  joint 
  of 
  the 
  first 
  pair 
  carries 
  a 
  very 
  large 
  and 
  flat- 
  

   tened 
  plumose 
  seta 
  on 
  its 
  outer 
  margin; 
  the 
  terminal 
  exopod 
  joint 
  

   of 
  the 
  second, 
  third, 
  and 
  fourth 
  pairs 
  is 
  armed 
  with 
  two 
  medium 
  

   spines 
  on 
  the 
  outer 
  margin 
  and 
  a 
  third 
  tmce 
  the 
  length, 
  or 
  even 
  more, 
  

   at 
  the 
  tip 
  ; 
  the 
  fifth 
  legs 
  are 
  smaller 
  than 
  in 
  the 
  female 
  but 
  similarly 
  

   two-jointed. 
  

  

  Color 
  the 
  same 
  but 
  lacldng 
  the 
  white 
  of 
  the 
  female 
  rej^roductive 
  

   oi^ans, 
  so 
  that 
  the 
  male 
  appears 
  considerably 
  darker. 
  

  

  Total 
  length, 
  1.10 
  mm. 
  Carapace, 
  0.36 
  mm. 
  long, 
  0.52 
  mm. 
  wide. 
  

   Free 
  thorax, 
  0.28 
  mm. 
  long. 
  

  

  (vcodpoc, 
  slow 
  or 
  sluggish.) 
  • 
  

  

  