﻿NO, 
  1950. 
  CRUSTACEAN 
  PARASITES 
  OF 
  FISH 
  AND 
  CRABS— 
  WILSON. 
  209 
  

  

  margin 
  straight, 
  deeply 
  incised 
  at 
  the 
  center; 
  lateral 
  areas 
  very 
  wide; 
  

   lateral 
  lobes 
  also 
  wide 
  and 
  short, 
  curved 
  strongly 
  inward 
  and 
  almost 
  

   squarely 
  truncated 
  at 
  the 
  ends 
  ; 
  median 
  lobe 
  a 
  little 
  more 
  than 
  one- 
  

   third 
  the 
  width 
  of 
  the 
  carapace, 
  with 
  projecting 
  corners 
  which 
  overlap 
  

   the 
  lateral 
  lobes, 
  and 
  an 
  emarginate 
  posterior 
  border. 
  Eye 
  minute, 
  

   one-third 
  the 
  length 
  of 
  the 
  carapace 
  behind 
  the 
  anterior 
  margin. 
  

   Free 
  segment 
  short, 
  two-sevenths 
  the 
  width 
  of 
  the 
  carapace; 
  genital 
  

   segment 
  acorn-shaped, 
  three-fourths 
  the 
  length 
  and 
  half 
  the 
  width 
  of 
  

   the 
  carapace, 
  with 
  wide 
  and 
  bluntly 
  rounded 
  posterior 
  lobes. 
  

  

  Abdomen 
  one-jointed, 
  three-sevenths 
  of 
  the 
  width 
  and 
  a 
  little 
  more 
  

   than 
  half 
  the 
  length 
  of 
  the 
  genital 
  segment; 
  anal 
  laminae 
  minute, 
  

   widely 
  separated, 
  each 
  tipped 
  with 
  four 
  short 
  setae. 
  

  

  Egg-tubes 
  three-fourths 
  the 
  width 
  of 
  the 
  abdomen 
  and 
  a 
  little 
  more 
  

   than 
  half 
  the 
  length 
  of 
  the 
  body. 
  

  

  Terminal 
  joints 
  of 
  the 
  first 
  antennae 
  very 
  slender, 
  much 
  longer 
  than 
  

   the 
  basal 
  joints, 
  ten 
  times 
  as 
  long 
  as 
  wide. 
  Second 
  antennae 
  rather 
  

   slender, 
  with 
  a 
  long 
  terminal 
  claw 
  bent 
  at 
  a 
  right 
  angle 
  near 
  the 
  tip. 
  

   Maxillary 
  hooks 
  short 
  and 
  nearly 
  straight, 
  with 
  a 
  strongly 
  inflated 
  

   base; 
  first 
  maxillae 
  short 
  and 
  triangular, 
  with 
  a 
  small 
  secondary 
  

   spine 
  near 
  the 
  center 
  of 
  the 
  inner 
  margin. 
  Maxillipeds 
  with 
  a 
  stout 
  

   terminal 
  claw 
  fully 
  as 
  long 
  as 
  the 
  moderately 
  inflated 
  basal 
  joint 
  and 
  

   strongly 
  curved. 
  Furca 
  with 
  an 
  exceptionally 
  broad, 
  three-lobed 
  

   base 
  and 
  the 
  short 
  rami 
  curved 
  so 
  as 
  to 
  form 
  together 
  a 
  half 
  circle. 
  

   First 
  swimming 
  legs 
  with 
  a 
  very 
  rudimentary 
  one-jointed 
  endopod, 
  

   and 
  with 
  short 
  plumose 
  setae 
  on 
  the 
  terminal 
  joint 
  of 
  the 
  exopod; 
  

   second 
  legs 
  with 
  medium-sized 
  spines 
  on 
  the 
  exopod, 
  whose 
  second 
  

   joint 
  carries 
  an 
  exceptionally 
  wide 
  rowing 
  seta; 
  rami 
  of 
  third 
  legs 
  

   close 
  together, 
  the 
  spine 
  on 
  the 
  exopod 
  long 
  and 
  stout 
  and 
  bent 
  into 
  

   a 
  half 
  circle; 
  fourth 
  legs 
  four-jointed 
  with 
  five 
  spines 
  subequal 
  in 
  

   length. 
  

  

  Cement 
  glands 
  situated 
  far 
  forward 
  in 
  the 
  genital 
  segment 
  and 
  

   inclined 
  outward, 
  the 
  divisions 
  of 
  the 
  glandular 
  portion 
  showing 
  like 
  

   a 
  string 
  of 
  beads 
  through 
  their 
  center. 
  

  

  Color 
  a 
  clear 
  cartilage-gray, 
  very 
  translucent 
  except 
  toward 
  the 
  

   margin, 
  with 
  ten 
  small 
  circular 
  pigment 
  spots 
  of 
  dark 
  bluish-purple 
  

   on 
  the 
  dorsal 
  surface 
  of 
  the 
  carapace, 
  arranged 
  in 
  pairs. 
  

  

  Total 
  length, 
  4 
  mm. 
  Carapace, 
  1.75 
  mm. 
  long, 
  2 
  mm. 
  wide. 
  

   Genital 
  segment, 
  1.3 
  mm. 
  long, 
  1 
  mm. 
  wide. 
  Abdomen, 
  0.8 
  mm. 
  

   long, 
  0.5 
  mm. 
  wide. 
  Egg-strings 
  2.25 
  mm. 
  long, 
  0.33 
  mm. 
  wide. 
  

  

  2Iale. 
  — 
  Carapace 
  in 
  all 
  respects 
  similar 
  to 
  that 
  of 
  the 
  female, 
  but 
  

   proportionally 
  larger; 
  free 
  segment 
  longer 
  and 
  contracted 
  into 
  a 
  

   neck 
  anteriorly 
  and 
  posteriorly; 
  genital 
  segment 
  barrel-shaped, 
  with 
  

   moderately 
  curved 
  sides 
  and 
  small 
  posterior 
  lobes 
  closely 
  approxi- 
  

   mated 
  to 
  the 
  sides 
  of 
  the 
  abdomen, 
  which 
  latter 
  is 
  almost 
  as 
  wide 
  as 
  

   69077°— 
  Proc.N.M.vol.44— 
  13 
  14 
  

  

  