﻿NO. 
  1950. 
  CRUSTACEAN 
  PARASITES 
  OF 
  FISH 
  AND 
  CRABS— 
  WILSON. 
  205 
  

  

  Uterine 
  processes 
  of 
  the 
  oviducts 
  filling 
  the 
  posterior 
  fourth 
  of 
  the 
  

   cephalothorax 
  and 
  the 
  second, 
  third, 
  and 
  fourth 
  segments, 
  sending 
  a 
  

   branch 
  out 
  into 
  the 
  base 
  of 
  each 
  of 
  the 
  swimming 
  legs. 
  

  

  Color 
  a 
  dark 
  gray, 
  the 
  cephalothorax 
  nearly 
  transparent, 
  the 
  

   uterine 
  processes 
  snow-white. 
  

  

  Total 
  length, 
  1.25 
  mm. 
  Cephalothorax, 
  0.5 
  mm. 
  long, 
  0.45 
  mm. 
  

   wide. 
  Free 
  thorax, 
  0.5 
  mm. 
  long, 
  0.25 
  mm. 
  wide. 
  Egg-strings, 
  1.5 
  

   mm. 
  long, 
  0.1 
  mm. 
  wide. 
  

  

  (uniseriatus, 
  arranged 
  in 
  a 
  single 
  series, 
  alluding 
  to 
  the 
  eggs.) 
  

  

  The 
  present 
  genus 
  was 
  created 
  by 
  Brian 
  in 
  1906 
  for 
  some 
  parasites 
  

   which 
  had 
  been 
  obtained 
  from 
  the 
  eye 
  of 
  "■ 
  Clwpea 
  alosa.^' 
  The 
  

   naming 
  of 
  the 
  genus 
  was 
  unfortunate 
  in 
  every 
  particular. 
  The 
  name 
  

   Eucanthus 
  given 
  by 
  Claus 
  had 
  been 
  preoccupied 
  many 
  years 
  before 
  

   for 
  a 
  genus 
  of 
  coleoptera 
  and 
  hence 
  can 
  not 
  stand. 
  We 
  thus 
  have 
  a 
  

   Pseudoeucanthus 
  but 
  no 
  Eucanthus. 
  

  

  Again, 
  Claus's 
  genus 
  was 
  distinguished 
  from 
  Bomolochus 
  by 
  the 
  

   presence 
  of 
  maxillary 
  hooks 
  and 
  by 
  the 
  normal 
  position 
  of 
  the 
  maxil- 
  

   lipeds 
  behind 
  the 
  other 
  mouth 
  parts. 
  Brian's 
  genus 
  shows 
  neither 
  of 
  

   these 
  peculiarities 
  but 
  has 
  the 
  mouth 
  parts 
  like 
  those 
  of 
  Bomolochus, 
  

   and 
  might 
  far 
  better 
  have 
  been 
  called 
  Pseudohomolochus. 
  Indeed, 
  

   while 
  it 
  is 
  easily 
  distinguished 
  from 
  Eucanthus 
  (Anchistrotos) 
  , 
  what 
  it 
  

   really 
  demands 
  is 
  a 
  better 
  separation 
  from 
  Bomolochus. 
  This 
  may 
  be 
  

   stated 
  as 
  follows: 
  First 
  antennae 
  neither 
  enlarged 
  nor 
  curved 
  at 
  the 
  

   base 
  and 
  destitute 
  of 
  tactile 
  setse; 
  maxillipeds 
  without 
  plumose 
  setse 
  

   or 
  accessory 
  spines; 
  exopod 
  segments 
  of 
  the 
  second, 
  third, 
  and 
  fourth 
  

   legs 
  fused 
  and 
  only 
  the 
  terminal 
  joint 
  armed 
  with 
  plumose 
  setse; 
  

   single 
  ramus 
  of 
  the 
  fifth 
  legs 
  longer 
  and 
  wider 
  than 
  any 
  of 
  the 
  others; 
  

   each 
  anal 
  lamina 
  tipped 
  with 
  a 
  single-jointed 
  seta 
  and 
  small 
  spines; 
  

   genital 
  segment 
  very 
  short 
  and 
  carrying 
  rudimentary 
  sixth 
  legs; 
  eggs 
  

   very 
  large, 
  in 
  two 
  rows 
  only 
  or 
  even 
  mostly 
  uniseriate, 
  forming 
  

   strings 
  similar 
  to 
  those 
  in 
  the 
  Caligidse 
  and 
  unlike 
  the 
  rest 
  of 
  the 
  

   ErgasiUdse. 
  

  

  These 
  specimens, 
  obtained 
  and 
  examined 
  alive, 
  enable 
  us 
  to 
  

   decide 
  all 
  those 
  points 
  in 
  Brian's 
  original 
  description 
  which 
  needed 
  

   confirmation 
  or 
  correction.^ 
  

  

  1 
  . 
  There 
  are 
  four 
  free 
  segments 
  in 
  front 
  of 
  the 
  genital 
  segment 
  as 
  

   in 
  Bomolochus. 
  The 
  first 
  of 
  these, 
  really 
  the 
  second 
  thorax 
  segment, 
  

   is 
  very 
  short 
  and 
  narrower 
  than 
  the 
  third 
  segment. 
  This 
  segment 
  

   is 
  not 
  indicated 
  in 
  Brian's 
  figures 
  or 
  description. 
  

  

  2. 
  This 
  genus 
  possesses 
  first 
  maxillae 
  similar 
  to 
  those 
  in 
  the 
  other 
  

   genera 
  of 
  the 
  family. 
  

  

  3. 
  The 
  specimen 
  figured 
  by 
  Brian 
  as 
  a 
  "male(?)" 
  was 
  really 
  a 
  

   female 
  without 
  egg-strings. 
  

  

  I 
  See 
  Proc. 
  U. 
  S. 
  Nat. 
  Mus., 
  vol. 
  39, 
  p. 
  381. 
  

  

  