﻿6 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  67 
  

  

  C. 
  2 
  Head 
  not 
  prominently 
  narrowed 
  posteriorly 
  ; 
  posterior 
  femora 
  nearly 
  

   reaching 
  or 
  passing 
  abdominal 
  apex 
  ; 
  head 
  between 
  antenniferous 
  

   tubercles 
  distinctly 
  spinous 
  or 
  tuberculous. 
  

  

  METAPTERARIA. 
  

   Ischnonyctes. 
  

  

  The 
  criticisms 
  of 
  Stal's 
  definitions 
  of 
  the 
  tribes 
  mostly 
  apply 
  to 
  

   Distant's 
  efforts 
  also; 
  and 
  the 
  lack 
  of 
  contrast 
  in 
  the 
  characters 
  as- 
  

   signed 
  to 
  the 
  last 
  two 
  tribes 
  is 
  even 
  more 
  apparent. 
  The 
  truth 
  is 
  

   that 
  the 
  exact 
  nature 
  of 
  important 
  characters 
  has 
  been 
  overlooked 
  

   and 
  an 
  attempt 
  made 
  to 
  define 
  tribes 
  upon 
  criteria 
  not 
  acceptable 
  

   even 
  for 
  the 
  differentiation 
  of 
  genera. 
  In 
  our 
  view 
  attempting 
  to 
  

   recognize 
  tribes 
  of 
  Ploiariinae 
  is 
  no 
  more 
  likely 
  at 
  the 
  present 
  

   moment 
  to 
  elucidate 
  the 
  relationships 
  of 
  the 
  genera, 
  than 
  one 
  would 
  

   be 
  led 
  to 
  suppose 
  from 
  the 
  futile 
  attempts 
  of 
  the 
  past. 
  

  

  CHARACTERS 
  USED 
  FOR 
  THE 
  RECOGNITION 
  OF 
  GENERA. 
  

  

  In 
  arriving 
  at 
  decisions 
  as 
  to 
  what 
  groups 
  constitute 
  valid 
  genera 
  

   and 
  subgenera 
  we 
  have 
  used 
  as 
  our 
  criteria 
  characters 
  that 
  appear 
  

   to 
  us 
  to 
  be 
  of 
  phylogenetic 
  value, 
  and 
  in 
  our 
  arrangement 
  have 
  in- 
  

   dicated 
  what 
  are 
  in 
  our 
  opinion 
  evolutionary 
  steps 
  insofar 
  as 
  the 
  

   available 
  material 
  has 
  permitted. 
  

  

  We 
  have 
  used 
  the 
  wing 
  venation 
  to 
  a 
  greater 
  extent 
  than 
  has 
  

   previously 
  been 
  attempted 
  in 
  this 
  group, 
  and 
  this 
  character 
  has 
  

   proved 
  very 
  useful 
  in 
  the 
  alignment 
  of 
  related 
  forms. 
  As 
  noted 
  above 
  

   the 
  structure 
  ®f 
  the 
  fore 
  legs 
  and 
  their 
  armatures, 
  and 
  especially 
  the 
  

   segmentation 
  and 
  form 
  of 
  the 
  fore 
  tarsi, 
  have 
  been 
  used 
  to 
  an 
  even 
  

   greater 
  extent 
  than 
  in 
  preceding 
  works 
  upon 
  this 
  subfamily, 
  but 
  

   these 
  characters 
  have 
  invariably 
  been 
  correlated 
  with 
  venational 
  and 
  

   other 
  structural 
  characters 
  in 
  the 
  final 
  analysis 
  before 
  assigning 
  any 
  

   particular 
  species 
  to 
  a 
  genus 
  or 
  subgenus. 
  

  

  In 
  our 
  work 
  on 
  this 
  and 
  other 
  groups 
  we 
  have 
  endeavored 
  to 
  

   utilize 
  as 
  generic 
  indices 
  characters 
  which 
  appear 
  to 
  us 
  to 
  indicate 
  

   a 
  common 
  origin 
  for 
  the 
  included 
  species, 
  and 
  slight 
  departures 
  from 
  

   the 
  general 
  rule 
  such 
  as 
  we 
  find 
  in 
  Ploiaria 
  and 
  Ghilianella., 
  we 
  have 
  

   not 
  considered 
  as 
  sufficient 
  grounds 
  for 
  elevating 
  the 
  divergent 
  forms 
  

   to 
  full 
  generic 
  status. 
  Had 
  we 
  failed 
  to 
  find 
  the 
  intermediate 
  sub- 
  

   genus 
  Ploeodon.yx, 
  linking 
  GhUianella 
  s.s. 
  and 
  Lissonyx 
  we 
  would 
  

   very 
  probably 
  have 
  considered 
  the 
  latter 
  as 
  a 
  valid 
  genus 
  but 
  with 
  

   an 
  intermediate 
  form 
  present 
  it 
  is 
  undesirable 
  to 
  give 
  to 
  these 
  closely 
  

   related 
  segregates 
  the 
  same 
  rank 
  as 
  we 
  accord 
  to 
  such 
  distinctly 
  

   separated 
  genera 
  as 
  Gardena 
  and 
  Emesaya. 
  

  

  In 
  the 
  case 
  of 
  the 
  last 
  two 
  genera 
  there 
  is 
  a 
  striking 
  similarity 
  in 
  

   wing 
  venation 
  accompanying 
  a 
  great 
  dissimilarity 
  in 
  the 
  structure 
  

   of 
  the 
  fore 
  legs, 
  the 
  tarsi 
  of 
  Gardena 
  being 
  of 
  the 
  generalized 
  simple 
  

   type, 
  while 
  those 
  of 
  Einesaya 
  are 
  heavily 
  chitinized 
  and 
  subfused. 
  

  

  