﻿NO. 
  1950. 
  CRUSTACEAN 
  PARASITES 
  OF 
  FISH 
  AND 
  CRABS— 
  WILSON. 
  201 
  

  

  ine 
  processes 
  of 
  the 
  oviducts. 
  The 
  true 
  cephalothorax 
  forms 
  about 
  

   two-thirds 
  of 
  this 
  anterior 
  body 
  and 
  is 
  one-half 
  wider 
  than 
  long; 
  

   the 
  second 
  segment 
  is 
  narrowed 
  a 
  little 
  and 
  is 
  quite 
  short; 
  the 
  fused 
  

   third 
  and 
  fourth 
  segments 
  are 
  again 
  narrowed 
  a 
  little, 
  but 
  are 
  rounded 
  

   out 
  posteriorly 
  over 
  the 
  fifth 
  segment, 
  so 
  as 
  to 
  be 
  nearly 
  twice 
  the 
  

   length 
  of 
  the 
  second 
  segment. 
  

  

  A 
  minute 
  eye 
  is 
  plainly 
  visible, 
  placed 
  far 
  forward, 
  very 
  close 
  to 
  

   the 
  anterior 
  margin. 
  

  

  In 
  the 
  hinder 
  portion 
  of 
  the 
  body 
  the 
  fifth 
  segment 
  is 
  abruptly 
  

   narrowed 
  to 
  less 
  tlian 
  half 
  the 
  \vidth 
  of 
  the 
  fused 
  third 
  and 
  fourth 
  

   segments, 
  and 
  is 
  mostly 
  concealed 
  in 
  dorsal 
  view. 
  

  

  The 
  genital 
  segment 
  is 
  a 
  little 
  wider 
  than 
  the 
  fifth 
  segment 
  ante- 
  

   riorly 
  where 
  the 
  egg-strings 
  are 
  attached, 
  but 
  tapers 
  posteriorly. 
  

  

  The 
  abdomen 
  is 
  made 
  up 
  of 
  three 
  long 
  and 
  narrow 
  segments, 
  

   diminishing 
  regularly 
  in 
  size, 
  the 
  basal 
  one 
  the 
  same 
  length 
  as 
  the 
  

   genital 
  segment. 
  The 
  anal 
  laminae 
  are 
  as 
  long 
  as 
  the 
  terminal 
  abdo- 
  

   men 
  segment, 
  and 
  each 
  of 
  them 
  half 
  as 
  wide, 
  tapering 
  posteriorly 
  

   and 
  tipped 
  with 
  an 
  inner 
  seta 
  as 
  long 
  as 
  the 
  entire 
  abdomen, 
  an 
  outer 
  

   one 
  five-eighths 
  as 
  long, 
  and 
  two 
  minute 
  spines 
  at 
  the 
  base 
  on 
  the 
  

   outer 
  margin. 
  

  

  Egg-strings 
  spindle-shaped, 
  slightly 
  swollen 
  at 
  the 
  center, 
  with 
  

   bluntly 
  rounded 
  ends; 
  each 
  is 
  as 
  wide 
  as 
  the 
  genital 
  segment 
  and 
  

   as 
  long 
  as 
  the 
  narrowed 
  posterior 
  body; 
  eggs 
  numerous, 
  arranged 
  

   in 
  six 
  to 
  eight 
  longitudinal 
  rows, 
  about 
  eighteen 
  in 
  each 
  row. 
  

  

  First 
  antenna 
  long 
  and 
  stout, 
  the 
  basal 
  portion 
  not 
  much 
  enlarged, 
  

   but 
  furnished 
  with 
  a 
  dense 
  row 
  of 
  stout 
  setse 
  along 
  the 
  anterior 
  mar- 
  

   gin. 
  Between 
  these 
  antennae 
  on 
  the 
  ventral 
  margin 
  is 
  a 
  stout 
  furca 
  

   pointing 
  backward 
  and 
  composed 
  of 
  two 
  strong 
  spines 
  united 
  by 
  a 
  

   crossbar 
  at 
  their 
  base. 
  

  

  Second 
  antennas 
  large 
  and 
  stout, 
  three-jointed, 
  terminal 
  and 
  basal 
  

   joints 
  the 
  same 
  length, 
  the 
  middle 
  joint 
  less 
  than 
  half 
  as 
  long. 
  The 
  

   terminal 
  joint 
  is 
  corrugated 
  on 
  its 
  ventral 
  surface 
  and 
  tipped 
  with 
  a 
  

   stout 
  claw, 
  as 
  long 
  as 
  the 
  joint 
  itself 
  and 
  well 
  curved, 
  with 
  a 
  bristling 
  

   row 
  of 
  spines 
  of 
  varying 
  lengths 
  around 
  its 
  base. 
  Mouth-parts 
  close 
  

   behind 
  the 
  second 
  antennae; 
  upper 
  lip 
  triangular, 
  one-fifth 
  wider 
  

   than 
  long, 
  a 
  rounded 
  angle 
  turned 
  forward 
  while 
  the 
  lateral 
  margins 
  

   are 
  straight; 
  the 
  lateral 
  angles 
  project 
  as 
  rounded 
  knobs 
  and 
  the 
  

   posterior 
  margui 
  is 
  strongly 
  convex. 
  

  

  Mandibles 
  simple, 
  turned 
  backward 
  beneath 
  the 
  upper 
  lip 
  and 
  

   tipped 
  »with 
  a 
  single 
  straight 
  spme. 
  First 
  maxilla 
  a 
  rounded 
  knob 
  

   armed 
  with 
  three 
  plumose 
  setae 
  which 
  diminish 
  in 
  size 
  from 
  witliin 
  

   outward. 
  Second 
  maxilla 
  short 
  and 
  stout, 
  turned 
  forward 
  and 
  

   armed 
  with 
  a 
  small 
  spine 
  on 
  the 
  posterior 
  margin, 
  and 
  tipped 
  with 
  

   two 
  straight 
  spines, 
  the 
  inner 
  of 
  which 
  is 
  twice 
  the 
  size 
  of 
  the 
  outer. 
  

   Maxillipeds 
  reaching 
  forward 
  outside 
  the 
  other 
  mouth 
  parts 
  nearly 
  

  

  