﻿236 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  vol.44. 
  

  

  laminse 
  are 
  so 
  short 
  that 
  these 
  masses 
  seem 
  to 
  rest 
  directly 
  upon 
  the 
  

   ventral 
  surface 
  of 
  the 
  abdomen. 
  

  

  First 
  antermse 
  six-jointed, 
  slender, 
  and 
  well 
  armed 
  with 
  setae; 
  sec- 
  

   ond 
  pair 
  stout, 
  with 
  swollen 
  basal 
  joints 
  and 
  short 
  and 
  stout 
  terminal 
  

   claws. 
  First 
  maxillae 
  simple, 
  two-jointed, 
  and 
  tipped 
  with 
  a 
  single 
  

   short 
  and 
  stout 
  spine; 
  second 
  maxillae 
  and 
  maxillipeds 
  with 
  short 
  

   and 
  rather 
  weak 
  terminal 
  claws, 
  and 
  moderately 
  swollen 
  basal 
  joints. 
  

  

  First 
  and 
  second 
  legs 
  very 
  rudimentary, 
  each 
  leg 
  consisting 
  of 
  a 
  

   one-jointed 
  process 
  divided 
  at 
  the 
  tip. 
  In 
  the 
  first 
  legs 
  these 
  processes 
  

   are 
  short 
  and 
  broad, 
  but 
  in 
  the 
  second 
  legs 
  they 
  are 
  narrow 
  and 
  acu- 
  

   rmnate. 
  The 
  third 
  and 
  fourth 
  legs 
  are 
  peculiar 
  and 
  quite 
  different 
  

   from 
  anything 
  thus 
  far 
  found 
  in 
  Lernanthropus. 
  The 
  third 
  pair 
  on 
  

   the 
  outside 
  pass 
  insensibly 
  into 
  the 
  posterior 
  skirts 
  of 
  the 
  third 
  

   segment; 
  in 
  the 
  center 
  is 
  a 
  short 
  plicate 
  portion, 
  and 
  on 
  the 
  inside 
  

   is 
  a 
  long 
  and 
  flattened 
  endopod, 
  pointed 
  at 
  the 
  tip, 
  which 
  reaches 
  

   back 
  beyond 
  the 
  fourth 
  legs 
  to 
  the 
  posterior 
  border 
  of 
  the 
  fourth 
  

   dorsal 
  plate. 
  These 
  legs 
  therefore 
  cover 
  and 
  conceal 
  the 
  fourth 
  pair, 
  

   a 
  condition 
  never 
  found 
  in 
  Lernanthropus. 
  The 
  fourth 
  legs 
  are 
  

   made 
  up 
  of 
  a 
  narrow 
  endopod 
  and 
  a 
  much 
  wider 
  exopod, 
  each 
  

   strongly 
  flattened 
  and 
  enlarged 
  into 
  the 
  shape 
  of 
  a 
  spatula, 
  and 
  fur- 
  

   nished 
  with 
  a 
  narrow 
  tip 
  like 
  a 
  whiplash, 
  attached 
  to 
  the 
  end 
  of 
  the 
  

   endopod 
  and 
  to 
  the 
  iimer 
  margin 
  of 
  the 
  exopod. 
  The 
  function 
  of 
  

   these 
  flagellate 
  portions 
  is 
  difficult 
  to 
  surmise. 
  

  

  Color 
  a 
  uniform 
  yellowish-gray 
  without 
  pigment 
  markings. 
  

  

  Total 
  length, 
  5.75 
  mm. 
  Cephalothorax, 
  1.45 
  mm. 
  long, 
  1.85 
  mm. 
  

   wide. 
  Second 
  thorax 
  segment, 
  2.95 
  mm. 
  mde. 
  Third 
  segment, 
  4 
  

   mm. 
  wide. 
  

  

  iflagellatum, 
  furnished 
  with 
  flagella 
  or 
  whiplashes, 
  alluding 
  to 
  the 
  

   fourth 
  legs.) 
  

  

  This 
  genus 
  may 
  be 
  readily 
  distinguished 
  from 
  Lernanthropus 
  by 
  

   the 
  rostrum 
  and 
  wings 
  of 
  the 
  cephalothorax, 
  by 
  the 
  long 
  endopods 
  

   of 
  the 
  third 
  legs, 
  and 
  by 
  the 
  lash-like 
  tips 
  of 
  the 
  fourth 
  legs. 
  They 
  

   are 
  not 
  at 
  all 
  common, 
  this 
  one 
  lot 
  being 
  all 
  that 
  were 
  found 
  for 
  the 
  

   entire 
  season. 
  

  

  NEMESIS 
  VERSICOLOR, 
  new 
  species. 
  

   Plate 
  38, 
  figs. 
  190-194; 
  plate 
  40. 
  

  

  Host 
  and 
  record 
  of 
  specimens. 
  — 
  A 
  single 
  lot 
  of 
  six 
  specimens, 
  includ- 
  

   ing 
  both 
  sexes, 
  was 
  obtained 
  from 
  the 
  gills 
  of 
  the 
  hammer-head 
  shark, 
  

   Sphyrna 
  zygsena, 
  June 
  17, 
  1910. 
  The 
  females 
  were 
  found 
  on 
  the 
  

   tips 
  of 
  the 
  gill 
  filaments, 
  indiscriminately 
  arranged, 
  while 
  the 
  males 
  

   were 
  attached 
  to 
  the 
  inner 
  surface 
  of 
  the 
  filaments 
  some 
  distance 
  

   from 
  the 
  tips. 
  

  

  Type-specimen.— 
  A 
  female, 
  Cat. 
  No. 
  43602, 
  U.S.N.M. 
  Paratypes, 
  

   Cat. 
  No. 
  42294, 
  U.S.N.M. 
  

  

  