﻿NO. 
  1980. 
  CRUSTACEAN 
  PARASITES 
  OF 
  FISH 
  AND 
  CRABS— 
  WILSON. 
  247 
  

  

  legs 
  visible 
  doreally. 
  Fifth 
  segment 
  forming 
  a 
  short 
  and 
  blunt 
  lobe 
  

   on 
  either 
  side 
  of 
  the 
  genital 
  segment 
  posteriorly, 
  the 
  tip 
  of 
  the 
  lobe 
  

   just 
  reaching 
  the 
  posterior 
  margm 
  of 
  the 
  opening 
  of 
  the 
  oviduct. 
  

   Fused 
  sixth 
  segment 
  and 
  abdomen 
  semielliptical, 
  about 
  the 
  same 
  

   length 
  and 
  width, 
  which 
  is 
  one-third 
  that 
  of 
  the 
  fifth 
  segment. 
  Anal 
  

   laminae 
  minute 
  and 
  widely 
  separated, 
  each 
  tipped 
  with 
  three 
  setae. 
  

  

  Egg-strings 
  half 
  the 
  entire 
  length, 
  and 
  half 
  the 
  width 
  of 
  the 
  fifth 
  

   segment, 
  about 
  twenty 
  eggs 
  in 
  each 
  strmg. 
  

  

  First 
  antennae 
  short, 
  their 
  basal 
  jomts 
  fused 
  into 
  a 
  sort 
  of 
  rostrum, 
  

   projecting 
  from 
  the 
  center 
  of 
  the 
  anterior 
  margin, 
  but 
  curved 
  over 
  

   ventrally 
  so 
  as 
  to 
  be 
  concealed 
  beneath 
  the 
  carapace. 
  They 
  are 
  

   apparently 
  made 
  up 
  of 
  only 
  three 
  jomts, 
  the 
  terminal 
  of 
  which 
  carries 
  

   all 
  the 
  spines. 
  Second 
  antennae 
  with 
  a 
  stout 
  and 
  strongly 
  curved 
  

   terminal 
  claw, 
  half 
  the 
  length 
  of 
  the 
  basal 
  joint. 
  Mouth 
  tube 
  wide 
  

   and 
  very 
  bluntly 
  rounded 
  at 
  the 
  tip 
  so 
  as 
  to 
  be 
  nearly 
  circular 
  in 
  

   ventral 
  outline. 
  The 
  two 
  terminal 
  joints 
  of 
  the 
  maxillipeds 
  are 
  

   longer 
  than 
  the 
  stout 
  basal 
  joint, 
  and 
  are 
  tipped 
  with 
  a 
  curved 
  claw, 
  

   which 
  has 
  an 
  accessory 
  spine 
  at 
  the 
  center 
  of 
  its 
  inner 
  margin. 
  There 
  

   is 
  also 
  a 
  short 
  curved 
  spine 
  projecting 
  from 
  the 
  top 
  of 
  a 
  small 
  papilla 
  

   on 
  the 
  ventral 
  surface 
  of 
  the 
  head 
  between 
  the 
  base 
  of 
  the 
  maxilliped 
  

   and 
  the 
  midlme. 
  This 
  is 
  not 
  the 
  rudiment 
  of 
  the 
  maxilla 
  since 
  it 
  is 
  

   behind 
  the 
  chitin 
  rib 
  which 
  supports 
  the 
  maxilliped. 
  

  

  Smmming 
  legs 
  with 
  two-jointed 
  exopods 
  and 
  one-jointed 
  endopods, 
  

   and 
  with 
  a 
  stout 
  spine 
  on 
  the 
  basal 
  joint 
  inside 
  of 
  the 
  endopod. 
  Both 
  

   rami 
  of 
  the 
  first 
  pair 
  are 
  tipped 
  with 
  four 
  spines; 
  the 
  exopod 
  of 
  the 
  

   second 
  pair 
  has 
  two, 
  the 
  endopod 
  three. 
  

  

  The 
  ovaries 
  and 
  oviducts 
  extend 
  the 
  entire 
  length 
  of 
  the 
  third, 
  

   fourth, 
  and 
  fifth 
  thorax 
  segments; 
  the 
  maturing 
  eggs 
  are 
  orange-brown 
  

   in 
  color; 
  the 
  cement 
  glands 
  are 
  close 
  to 
  the 
  midline 
  inside 
  of 
  the 
  ovi- 
  

   ducts, 
  and 
  are 
  one-fourth 
  the 
  length 
  of 
  the 
  latter, 
  with 
  a 
  short 
  

   glandular 
  portion. 
  

  

  Color 
  of 
  the 
  head 
  yellowish-gray, 
  translucent; 
  free 
  thorax 
  brownish- 
  

   yellow; 
  genital 
  segment 
  a 
  deeper 
  brown; 
  oviducts 
  and 
  egg-strings 
  

   medium 
  orange-brown 
  ; 
  lateral 
  margins 
  of 
  the 
  free 
  thorax 
  and 
  genital 
  

   segment 
  with 
  an 
  olive-green 
  tinge; 
  central 
  line 
  over 
  the 
  intestine 
  

   yellow, 
  bordered 
  with 
  orange. 
  In 
  many 
  specimens 
  the 
  muscles 
  of 
  

   the 
  head 
  and 
  free 
  thorax 
  are 
  deep 
  red, 
  showing 
  prominently 
  through 
  

   the 
  translucent 
  carapace 
  and 
  dorsal 
  epidermis. 
  

  

  Total 
  length, 
  2.33 
  mm. 
  Carapace, 
  0.26 
  mm. 
  long 
  and 
  wide. 
  First 
  

   and 
  second 
  thorax 
  segments, 
  0.33 
  mm. 
  long, 
  0.39 
  mm. 
  wide. 
  Third, 
  

   fourth, 
  and 
  fifth 
  segments, 
  1.75 
  mm. 
  long, 
  0.33 
  mm. 
  wide. 
  Egg- 
  

   strings, 
  1.2 
  mm. 
  long. 
  

  

  (linearis, 
  narrow, 
  thread-like.) 
  

  

  This 
  species 
  is 
  radically 
  different 
  from 
  all 
  the 
  others 
  that 
  have 
  been 
  

   obtained 
  in 
  several 
  particulars. 
  The 
  most 
  striking 
  peculiarity 
  is 
  the 
  

  

  