﻿the 
  Species 
  of 
  Liinnoria. 
  

  

  387 
  

  

  Notwithstanding 
  tliese 
  many 
  points 
  of 
  resemblance, 
  there 
  

   are, 
  however, 
  some 
  minute 
  characters 
  by 
  which 
  most 
  of 
  the 
  

   species 
  can 
  be 
  distinguished. 
  The 
  most 
  important 
  of 
  these 
  

   seem 
  to 
  me 
  to 
  be 
  the 
  characters 
  of 
  the 
  mandibles 
  and 
  the 
  

   maxilHpeds. 
  The 
  exact 
  relationships 
  of 
  the 
  species 
  seem 
  

   rather 
  difficult 
  to 
  disentangle, 
  but 
  the 
  species 
  may 
  readily 
  be 
  

   distinguished 
  in 
  the 
  following 
  way 
  : 
  — 
  

  

  Ai-tijlcial 
  Key 
  to 
  the 
  Species, 
  

  

  , 
  ) 
  Palp 
  of 
  mandible 
  two-jointed 
  L- 
  segnis. 
  

  

  I 
  Palp 
  of 
  mandible 
  three-jointed. 
  2. 
  

  

  {Epipod 
  of 
  maxilliped 
  shorter 
  than 
  second 
  

   joint 
  L. 
  lignorum, 
  

   E})ipod 
  of 
  maxilliped 
  longer 
  than 
  second 
  

   joint. 
  3. 
  

  

  L. 
  japomca. 
  

   L. 
  andreiosi. 
  

  

  o 
  \ 
  Body 
  with 
  prominent 
  tubercles 
  on 
  pleon 
  .... 
  

   ' 
  I 
  Body 
  without 
  prominent 
  tubercles 
  on 
  pleon. 
  4. 
  

  

  {Peduncle 
  of 
  uropoda 
  shorter 
  than 
  inner 
  ramus. 
  

   Peduncle 
  of 
  uropoda 
  longer 
  than 
  inner 
  

   ramus. 
  6. 
  

  

  r. 
  i 
  Both 
  rami 
  of 
  uropods 
  very 
  short 
  L. 
  antarctica. 
  

  

  ) 
  Inner 
  rami 
  of 
  uropods 
  not 
  very 
  short 
  L. 
  pfefferi. 
  

  

  The 
  order 
  in 
  which 
  the 
  species 
  are 
  given 
  in 
  this 
  artifi- 
  

   cial 
  key 
  does 
  not 
  co'-respond 
  with 
  their 
  true 
  relationships 
  ; 
  

   the 
  following 
  tree 
  represents 
  my 
  idea 
  of 
  their 
  probable 
  origin 
  

   — 
  the 
  position 
  of 
  L. 
  japonica 
  is, 
  however, 
  uncertain, 
  as 
  no 
  

   definite 
  information 
  as 
  to 
  its 
  mouth-parts 
  is 
  available 
  : 
  — 
  

  

  L. 
  segnis. 
  L. 
  antarctica. 
  L. 
  pfefferi. 
  L. 
  andrewsi. 
  L. 
  lignorum. 
  L. 
  japonica. 
  

  

  It 
  is 
  always 
  important 
  to 
  connect 
  the 
  characters 
  by 
  which 
  

   species 
  of 
  a 
  genus 
  are 
  related 
  to 
  one 
  another 
  with 
  their 
  

  

  