﻿•218 
  PROCEEDiyGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  vol.44. 
  

  

  and 
  at 
  right 
  angles 
  to 
  the 
  body 
  axis, 
  and 
  appearing 
  in 
  dorsal 
  view 
  

   just 
  behind 
  the 
  posterior 
  lobes 
  of 
  the 
  carapace; 
  the 
  endopod 
  is 
  carried 
  

   at 
  right 
  angles 
  to 
  the 
  exopod, 
  or 
  parallel 
  to 
  the 
  body 
  axis. 
  Third 
  

   legs 
  reduced 
  far 
  more 
  than 
  is 
  usual 
  in 
  the 
  genus, 
  the 
  spine 
  on 
  the 
  exopod 
  

   straight 
  instead 
  of 
  curved, 
  the 
  terminal 
  joint 
  with 
  four 
  spines 
  but 
  

   only 
  a 
  single 
  seta; 
  the 
  endopod 
  contains 
  but 
  one 
  partial 
  joint, 
  which 
  is 
  

   fused 
  to 
  the 
  basal 
  plate. 
  Foui'th 
  legs 
  stout 
  and 
  of 
  the 
  usual 
  pattern, 
  

   three-jointed, 
  the 
  inner 
  terminal 
  spuie 
  two 
  and 
  a 
  half 
  times 
  as 
  long 
  as 
  

   the 
  other 
  four 
  which 
  are 
  about 
  equal. 
  Fifth 
  legs 
  present 
  just 
  in 
  

   front 
  of 
  the 
  posterior 
  corners 
  of 
  the 
  genital 
  segment, 
  the 
  endopod 
  

   represented 
  by 
  a 
  single 
  spine, 
  the 
  exopod 
  by 
  a 
  papilla 
  tipped 
  with 
  two 
  

   spines. 
  

  

  Color 
  a 
  light 
  cartilage-gray, 
  exceptionally 
  translucent 
  and 
  orna- 
  

   mented 
  on 
  the 
  dorsal 
  surface 
  of 
  the 
  carapace 
  with 
  a 
  few 
  scattered 
  and 
  

   irregular 
  spots 
  of 
  purple 
  pigment. 
  

  

  Total 
  length, 
  2.15 
  mm. 
  Carapace, 
  0.95 
  mm. 
  long, 
  0.75 
  mm. 
  wide. 
  

   Genital 
  segment, 
  0.9 
  mm. 
  long, 
  0.6 
  mm. 
  wide. 
  Egg-strings, 
  0.8 
  mm. 
  

   long, 
  0.28 
  mm. 
  wide. 
  

  

  Male. 
  — 
  General 
  form 
  narrow 
  and 
  elongate; 
  carapace 
  exactly 
  like 
  

   that 
  of 
  the 
  female, 
  but 
  the 
  posterior 
  body 
  much 
  narrower. 
  Lunules 
  

   larger 
  and 
  semicircular; 
  eye 
  farther 
  back 
  in 
  the 
  carapace; 
  posterior 
  

   sinuses 
  even 
  shallower 
  than 
  in 
  the 
  female. 
  

  

  Genital 
  segment 
  barrel-shaped, 
  considerably 
  less 
  than 
  half 
  the 
  

   width 
  of 
  the 
  carapace 
  and 
  just 
  about 
  half 
  the 
  length. 
  

  

  Abdomen 
  two-thirds 
  as 
  wide 
  and 
  three-fifths 
  as 
  long 
  as 
  the 
  genital 
  

   segment; 
  anal 
  lamina3 
  large, 
  each 
  tipped 
  with 
  three 
  medium-sized 
  

   setae 
  and 
  two 
  short 
  spines 
  on 
  the 
  outer 
  margin. 
  

  

  Appendages 
  like 
  those 
  of 
  the 
  female, 
  with 
  the 
  following 
  exceptions: 
  

   The 
  first 
  antennas 
  reach 
  fully 
  to 
  the 
  lateral 
  margins 
  of 
  the 
  carapace; 
  

   the 
  terminal 
  claw 
  on 
  the 
  second 
  pair 
  has 
  the 
  usual 
  accessory 
  spines 
  

   and 
  corrugated 
  surfaces 
  found 
  in 
  the 
  male 
  sex 
  ; 
  the 
  maxillary 
  hook 
  is 
  

   enormously 
  enlarged, 
  so 
  that 
  it 
  is 
  larger 
  than 
  the 
  claw 
  on 
  the 
  second 
  

   antenna; 
  the 
  basal 
  joint 
  of 
  the 
  maxilliped 
  is 
  much 
  swollen, 
  and 
  is 
  

   armed 
  with 
  a 
  stout 
  spine 
  on 
  its 
  inner 
  margin, 
  which 
  interlocks 
  with 
  

   the 
  tip 
  of 
  the 
  terminal 
  claw 
  ; 
  the 
  accessory 
  spine 
  on 
  the 
  latter 
  claw 
  is 
  

   close 
  to 
  the 
  base 
  instead 
  of 
  near 
  the 
  tip. 
  

  

  Color 
  as 
  in 
  the 
  female. 
  

  

  Total 
  length, 
  1.6 
  mm. 
  Carapace, 
  0.8 
  mm. 
  long, 
  0.6 
  mm. 
  wide. 
  

   Genital 
  segment, 
  0.4 
  mm. 
  long, 
  0.25 
  mm. 
  wide. 
  

  

  (enormis, 
  irregular, 
  unusual.) 
  

  

  This 
  little 
  Caligus 
  is 
  irregular 
  in 
  many 
  respects, 
  such 
  as 
  the 
  extreme 
  

   reduction 
  of 
  the 
  maxillary 
  hooks 
  in 
  the 
  female 
  and 
  their 
  enormous 
  

   enlargement 
  in 
  the 
  male; 
  in 
  the 
  almost 
  complete 
  obliteration 
  of 
  the 
  

   lunules 
  in 
  the 
  female; 
  in 
  the 
  great 
  reduction 
  of 
  the 
  maxillae 
  in 
  both 
  

   sexes; 
  in 
  the 
  absence 
  of 
  a 
  furca; 
  in 
  the 
  lack 
  of 
  plumose 
  setae 
  on 
  the 
  first 
  

  

  