﻿NO. 
  1950. 
  CRUSTACEAN 
  PARASITES 
  OF 
  FISH 
  AND 
  CRABS—WILSON. 
  237 
  

  

  Female. 
  — 
  General 
  body 
  form 
  oval, 
  two 
  and 
  one-half 
  times 
  as 
  long 
  

   as 
  wide, 
  narrowed 
  a 
  little 
  anteriorly 
  and 
  much 
  more 
  posteriorly. 
  

  

  Cephalothorax 
  covered 
  by 
  a 
  carapace 
  which 
  is 
  slightly 
  longer 
  than 
  

   wide 
  and 
  only 
  two-thirds 
  of 
  the 
  width 
  of 
  the 
  second 
  segment, 
  with 
  a 
  

   knob 
  on 
  each 
  lateral 
  margin 
  just 
  in 
  front 
  of 
  the 
  center. 
  Second, 
  tliird, 
  

   and 
  fourth 
  segments 
  each 
  covered 
  Avith 
  a 
  semicircular 
  carapace 
  

   which 
  extends 
  around 
  the 
  sides 
  of 
  the 
  body 
  to 
  the 
  ventral 
  surface, 
  

   the 
  three 
  carapaces 
  all 
  about 
  the 
  same 
  size. 
  Fifth 
  segment 
  narrowed 
  

   to 
  half 
  the 
  width 
  of 
  the 
  fourth 
  and 
  covered 
  on 
  the 
  dorsal 
  surface 
  only 
  

   with 
  a 
  carapace, 
  which 
  is 
  transversely 
  elliptical 
  and 
  does 
  not 
  reach 
  

   the 
  posterior 
  margin 
  of 
  the 
  segment. 
  Genital 
  segment 
  one-third 
  

   narrower 
  than 
  the 
  fifth 
  segment, 
  nearly 
  twice 
  as 
  wide 
  as 
  long, 
  with 
  

   the 
  egg-strings 
  attached 
  close 
  to 
  the 
  lateral 
  margins. 
  

  

  Abdomen 
  less 
  than 
  half 
  the 
  width 
  of 
  the 
  genital 
  segment 
  and 
  about 
  

   the 
  same 
  length, 
  made 
  up 
  of 
  three 
  joints, 
  the 
  terminal 
  of 
  which 
  is 
  as 
  

   long 
  as 
  the 
  two 
  basal 
  together. 
  Anal 
  laminae 
  oval 
  in 
  outline, 
  two- 
  

   thirds 
  as 
  long 
  as 
  th© 
  entire 
  abdomen, 
  each 
  tipped 
  with 
  four 
  short 
  

   spines. 
  

  

  Egg-cases 
  the 
  same 
  width 
  as 
  the 
  abdomen, 
  and 
  from 
  one 
  to 
  one 
  

   and 
  two-thirds 
  times 
  the 
  length 
  of 
  the 
  body; 
  eggs 
  large, 
  from 
  25 
  

   to 
  40 
  in 
  each 
  case. 
  

  

  First 
  antennae 
  slender 
  and 
  many-jointed, 
  tapering 
  gradually 
  to 
  

   the 
  tip, 
  and 
  attached 
  to 
  the 
  anterior 
  margin 
  of 
  the 
  head 
  close 
  to 
  the 
  

   dorsal 
  surface. 
  Second 
  antennae 
  four-jointed, 
  the 
  terminal 
  joint 
  a 
  

   long 
  sickle-shaped 
  claw; 
  the 
  tliird 
  and 
  fourth 
  joints 
  project 
  nearly 
  

   their 
  length 
  in 
  front 
  of 
  the 
  anterior 
  margin 
  of 
  the 
  head, 
  and 
  form 
  

   important 
  accessory 
  attachment 
  organs. 
  

  

  The 
  second 
  maxillae 
  are 
  two-jointed, 
  the 
  joints 
  about 
  the 
  same 
  

   length, 
  the 
  terminal 
  one 
  with 
  two 
  projections 
  at 
  the 
  tip 
  on 
  the 
  an- 
  

   terior 
  margin, 
  each 
  elliptical 
  in 
  outline, 
  and 
  about 
  as 
  long 
  as 
  the 
  

   terminal 
  joint 
  is 
  wide. 
  Maxillipeds 
  very 
  large 
  and 
  sickle-shaped, 
  

   projecting 
  their 
  entire 
  length 
  t)eyond 
  the 
  margin 
  of 
  the 
  carapace, 
  

   two-jointed, 
  the 
  terminal 
  joint 
  a 
  claw 
  which 
  is 
  slightly 
  shorter 
  than 
  

   the 
  basal 
  joint. 
  The 
  tip 
  of 
  this 
  claw 
  is 
  stained 
  a 
  deep 
  red 
  as 
  though 
  

   with 
  blood. 
  

  

  The 
  first 
  pair 
  of 
  legs 
  is 
  considerably 
  modified 
  in 
  form; 
  the 
  basal 
  

   joint 
  of 
  the 
  exopod 
  is 
  curved 
  inward, 
  narrowed 
  at 
  the 
  base 
  and 
  

   enlarged 
  at 
  the 
  tip 
  into 
  a 
  broad 
  spatula, 
  with 
  the 
  tiny 
  terminal 
  

   joint 
  attached 
  to 
  the 
  center 
  of 
  the 
  terminal 
  margin. 
  The 
  endopod 
  

   is 
  made 
  up 
  of 
  three 
  parts; 
  the 
  outer 
  of 
  these 
  is 
  very 
  narrow, 
  longer 
  

   than 
  the 
  others, 
  sickle-shaped, 
  and 
  curves 
  outward 
  over 
  the 
  basal 
  

   joint 
  of 
  the 
  exopod, 
  with 
  a 
  row 
  of 
  long 
  cylindrical 
  teeth 
  along 
  the 
  

   concave 
  and 
  convex 
  margins; 
  the 
  other 
  two 
  parts 
  are 
  shorter 
  and 
  

   stouter 
  and 
  are 
  covered 
  with 
  short 
  spines. 
  The 
  second, 
  tliird, 
  and 
  

   fourth 
  legs 
  are 
  biramose, 
  the 
  rami 
  are 
  two-jointed, 
  and 
  the 
  terminal 
  

  

  