﻿NO. 
  1950. 
  CRUSTACEAN 
  PARASITES 
  OF 
  FISH 
  AND 
  CRABS— 
  WILSON. 
  199 
  

  

  face 
  above 
  the 
  bases 
  of 
  the 
  two 
  finger 
  processes. 
  The 
  whole 
  ventral 
  

   surface 
  of 
  the 
  joint 
  itself 
  and 
  that 
  of 
  the 
  two 
  processes 
  are 
  covered 
  

   with 
  diagonal 
  corrugations. 
  

  

  The 
  upper 
  lip 
  is 
  one-half 
  wider 
  than 
  long, 
  with 
  convex 
  anterior 
  and 
  

   posterior 
  margins, 
  prominent 
  lateral 
  angles, 
  and 
  a 
  small 
  rounded 
  

   process 
  at 
  the 
  center 
  of 
  the 
  posterior 
  margin. 
  It 
  is 
  further 
  orna- 
  

   mented 
  on 
  the 
  ventral 
  surface 
  with 
  a 
  wide 
  ridge, 
  curving 
  inward 
  from 
  

   each 
  lateral 
  angle, 
  then 
  backward 
  to 
  the 
  posterior 
  margin, 
  and 
  then 
  

   inward 
  again 
  to 
  the 
  median 
  process. 
  

  

  The 
  mandibles 
  are 
  turned 
  backward 
  along 
  the 
  posterior 
  margin 
  of 
  

   the 
  lip 
  and 
  terniinate 
  in 
  a 
  straight 
  and 
  slender 
  spine. 
  

  

  The 
  first 
  maxillge 
  are 
  each 
  armed 
  with 
  three 
  setse, 
  the 
  two 
  inner 
  

   ones 
  close 
  together 
  and 
  the 
  same 
  length, 
  the 
  outer 
  one 
  removed 
  a 
  

   little 
  ways 
  from 
  them 
  and 
  only 
  one-fifth 
  as 
  long. 
  

  

  The 
  second 
  maxillae 
  are 
  rather 
  slender, 
  the 
  terminal 
  joint 
  being 
  

   inclined 
  forward 
  and 
  ending 
  in 
  a 
  single 
  smooth 
  spine. 
  The 
  maxilli- 
  

   peds 
  have 
  a 
  triangular 
  basal 
  joint 
  and 
  a 
  stout 
  terminal 
  claw 
  armed 
  

   with 
  a 
  small 
  and 
  slender 
  seta 
  on 
  the 
  inner 
  margin 
  of 
  the 
  proximal 
  

   curve 
  and 
  a 
  large 
  accessory 
  spine 
  on 
  the 
  outer 
  margin 
  of 
  the 
  distal 
  

   curve; 
  the 
  basal 
  joint 
  carries 
  two 
  stout 
  spines 
  close 
  together 
  at 
  the 
  

   center 
  of 
  its 
  inner 
  margin, 
  the 
  anterior 
  one 
  twice 
  the 
  size 
  of 
  the 
  

   posterior. 
  

  

  The 
  first 
  swimming 
  legs 
  have 
  a 
  two-jointed 
  exopod 
  and 
  a 
  three- 
  

   jointed 
  endopod; 
  the 
  second, 
  third, 
  and 
  fourth 
  legs 
  have 
  three- 
  

   jointed 
  rami, 
  with 
  the 
  spines 
  and 
  setae 
  arranged 
  as 
  follows: 
  Second 
  

   exopod, 
  I— 
  0, 
  I— 
  1, 
  III— 
  5; 
  endopod, 
  0—1, 
  0—2, 
  II— 
  3. 
  Third 
  exo- 
  

   pod, 
  I— 
  0, 
  II— 
  1, 
  II— 
  6; 
  endopod, 
  0—1,0— 
  2, 
  II— 
  2. 
  Fourth 
  exopod, 
  

   I— 
  0, 
  1— 
  1, 
  0—5; 
  endopod, 
  0—1, 
  0—1, 
  0—3. 
  

  

  Color 
  a 
  translucent 
  cartilage 
  gray, 
  oviducts 
  white, 
  egg-strings 
  light 
  

   gray. 
  

  

  Total 
  length, 
  2.28 
  mm. 
  Cephalothorax, 
  0.6 
  mm. 
  long, 
  1 
  mm. 
  wide. 
  

   Free 
  and 
  genital 
  segments, 
  1 
  mm. 
  long. 
  Abdomen, 
  0.9 
  mm. 
  long. 
  

   Egg-strings, 
  2.10 
  mm. 
  long. 
  

  

  (attenuatus, 
  very 
  slender, 
  alluding 
  to 
  the 
  first 
  antennae, 
  abdomen, 
  

   and 
  egg-strings.) 
  

  

  This 
  species 
  is 
  readily 
  distinguished 
  by 
  the 
  great 
  length 
  and 
  slender- 
  

   ness 
  of 
  its 
  first 
  antennae, 
  abdomen, 
  and 
  egg-strings, 
  by 
  the 
  armature 
  

   of 
  the 
  terminal 
  joint 
  of 
  the 
  second 
  antennae, 
  and 
  by 
  the 
  peculiar 
  shape 
  

   and 
  ornamentation 
  of 
  the 
  upper 
  lip. 
  

  

  It 
  is 
  not 
  at 
  all 
  a 
  common 
  species, 
  since 
  it 
  was 
  found 
  on 
  only 
  one 
  

   of 
  the 
  many 
  scorpion 
  fish 
  examined; 
  it 
  is, 
  of 
  course, 
  possible 
  that 
  this 
  

   is 
  not 
  its 
  regular 
  host, 
  but 
  it 
  was 
  not 
  found 
  on 
  any 
  of 
  the 
  other 
  fish 
  

   examined 
  during 
  the 
  season 
  of 
  1910. 
  

  

  