﻿NO, 
  1950. 
  CRUST 
  A 
  CEAN 
  PARASITES 
  OF 
  FISH 
  AND 
  CRABS— 
  WILSON. 
  211 
  

  

  median 
  lobe 
  half 
  the 
  diameter 
  of 
  the 
  carapace, 
  with 
  a 
  nearly 
  straight 
  

   posterior 
  margin 
  on 
  a 
  level 
  with 
  the 
  tips 
  of 
  the 
  lateral 
  lobes. 
  

  

  Free 
  segment 
  short, 
  about 
  one-fourth 
  the 
  width 
  of 
  the 
  carapace; 
  

   genital 
  segment 
  shaped 
  like 
  a 
  broad 
  acorn 
  with 
  a 
  slightly 
  reentrant 
  

   posterior 
  margin, 
  three-fourths 
  the 
  size 
  of 
  the 
  carapace, 
  without 
  

   lobes 
  or 
  fifth 
  legs. 
  

  

  Abdomen 
  two-jointed, 
  basal 
  joint 
  considerably 
  the 
  longer; 
  one- 
  

   third- 
  the 
  width 
  and 
  five-sevenths 
  the 
  length 
  of 
  the 
  genital 
  segment; 
  

   anal 
  laminae 
  short 
  and 
  wide, 
  each 
  tipped 
  mth 
  five 
  setae. 
  

  

  Of 
  the 
  appendages 
  the 
  maxillary 
  hooks 
  have 
  an 
  inflated 
  circular 
  

   base 
  and 
  a 
  long 
  and 
  strongly 
  curved 
  ramus. 
  First 
  maxillae 
  slender 
  

   and 
  extending 
  considerably 
  beyond 
  the 
  tip 
  of 
  the 
  mouth; 
  rudi- 
  

   mentary 
  endopods 
  present, 
  each 
  tipped 
  with 
  a 
  single 
  spine. 
  

  

  Mouth 
  tube 
  very 
  short 
  and 
  wide, 
  in 
  fact 
  almost 
  circular 
  in 
  ventral 
  

   outline. 
  Terminal 
  claw 
  of 
  maxillipeds 
  less 
  than 
  two-fifths 
  of 
  the 
  

   length 
  of 
  the 
  basal 
  joint, 
  stout 
  and 
  strongly 
  curved, 
  with 
  a 
  spine 
  on 
  

   its 
  inner 
  margin. 
  Furca 
  long 
  and 
  narrow, 
  contracted 
  at 
  the 
  base 
  

   of 
  the 
  rami, 
  which 
  are 
  slender, 
  bluntly 
  rounded 
  and 
  curved 
  like 
  

   parenthesis 
  marks. 
  First 
  swimming 
  legs 
  short 
  and 
  stout, 
  with 
  two 
  

   spines 
  on 
  the 
  ventral 
  surface 
  of 
  the 
  basal 
  joint 
  at 
  the 
  distal 
  end 
  and 
  

   one 
  on 
  the 
  posterior 
  margin; 
  rami 
  of 
  second 
  legs 
  equal 
  in 
  length, 
  

   the 
  spines 
  on 
  the 
  exopod 
  slender 
  and 
  weak; 
  rami 
  of 
  third 
  legs 
  well 
  

   separated, 
  short 
  and 
  wide; 
  fourth 
  legs 
  three-jointed 
  with 
  five 
  sub- 
  

   equal 
  spines. 
  Cement 
  glands 
  divergent, 
  with 
  their 
  bases 
  close 
  to 
  

   the 
  midline, 
  the 
  beaded 
  portion 
  narrow 
  and 
  extending 
  through 
  the 
  

   center 
  of 
  the 
  gland. 
  

  

  Color 
  a 
  uniform 
  cartilage-gray 
  without 
  pigment 
  marks 
  of 
  any 
  sort. 
  

  

  Total 
  length, 
  4.16 
  mm. 
  Carapace, 
  1.83 
  mm. 
  long, 
  1.6 
  mm. 
  wide. 
  

   Genital 
  segment, 
  1.25 
  mm. 
  long, 
  1 
  mm. 
  wide. 
  Abdomen, 
  0.92 
  mm. 
  

   long, 
  0.35 
  mm. 
  wide. 
  

  

  Male. 
  — 
  Carapace 
  similar 
  in 
  aU 
  respects 
  to 
  that 
  of 
  the 
  female, 
  but 
  

   proportionally 
  larger, 
  the 
  medium 
  lobe 
  projecting 
  a 
  little 
  behind 
  the 
  

   lateral 
  lobes; 
  genital 
  segment 
  barrel-shaped, 
  with 
  strongly 
  convex 
  

   sides 
  and 
  straight 
  anterior 
  and 
  posterior 
  margins 
  ; 
  both 
  the 
  fifth 
  and 
  

   the 
  sixth 
  legs 
  present, 
  the 
  former 
  just 
  behind 
  the 
  center 
  of 
  the 
  lateral 
  

   margin 
  and 
  tipped 
  with 
  a 
  single 
  spine, 
  the 
  latter 
  farther 
  back 
  and 
  

   more 
  prominent, 
  tipped 
  with 
  two 
  spines. 
  

  

  Basal 
  abdomen 
  joint 
  considerably 
  shorter 
  than 
  the 
  terminal; 
  anal 
  

   laminae 
  long 
  and 
  wide, 
  each 
  tipped 
  with 
  four 
  setae. 
  

  

  Second 
  antennse 
  with 
  a 
  swoUen 
  and 
  corrugated 
  basal 
  joint 
  and 
  an 
  

   exceptionally 
  short 
  and 
  stubby 
  terminal 
  claw; 
  maxiUary 
  hooks 
  en- 
  

   larged 
  so 
  that 
  they 
  are 
  longer 
  and 
  stouter 
  than 
  the 
  entire 
  second 
  

   antennae. 
  Maxillipeds 
  with 
  a 
  strongly 
  swoUen 
  basal 
  joint 
  armed 
  

   with 
  five 
  large 
  saw 
  teeth 
  on 
  its 
  inner 
  margin, 
  against 
  which 
  the 
  

   terminal 
  claw 
  shuts 
  when 
  closed. 
  

  

  