﻿2 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  67 
  

  

  in 
  having 
  the 
  costa 
  thickened 
  and 
  provided 
  with 
  a 
  fracture 
  (forming 
  

   what 
  are 
  called 
  embolium 
  and 
  cuneus). 
  

  

  Upon 
  consideration 
  it 
  becomes 
  apparent, 
  however, 
  that 
  having 
  

   characters 
  in 
  common 
  does 
  not 
  necessarily 
  imply 
  relationship. 
  The 
  

   eternal 
  question 
  of 
  taxonomy 
  arises, 
  as 
  to 
  whether 
  characters 
  are 
  of 
  

   phyletic 
  significance 
  or 
  are 
  mere 
  parallelisms. 
  The 
  antennal 
  and 
  

   chaetotactic 
  characters 
  so 
  similar 
  in 
  Cryptostemmatids 
  and 
  Lycto- 
  

   corids 
  may 
  be 
  only 
  parallel 
  adaptations 
  in 
  groups 
  frequenting 
  similar 
  

   environments. 
  On 
  the 
  other 
  hand, 
  the 
  excessive 
  development 
  of 
  

   the 
  coxae 
  in 
  Cryptostemmatids 
  which 
  has 
  resulted 
  in 
  great 
  diminu- 
  

   tion 
  in 
  size 
  of 
  the 
  pleura 
  and 
  conceivably 
  may 
  have 
  had 
  to 
  do 
  with 
  

   lack 
  of 
  metapleural 
  ostioles, 
  itself 
  is 
  an 
  adaptive 
  character 
  in 
  these 
  

   jumping 
  insects. 
  However, 
  when 
  we 
  note 
  that 
  the 
  Schizopterids 
  

   also 
  have 
  no 
  ostioles 
  (although 
  their 
  pleura 
  are 
  well 
  developed) 
  and 
  

   agree 
  with 
  the 
  Cryptostemmatids, 
  not 
  only 
  in 
  the 
  more 
  ordinary 
  

   tarsal, 
  rostral, 
  and 
  antennal 
  details, 
  but 
  also 
  in 
  peculiar 
  venational 
  

   characters, 
  we 
  must 
  conclude 
  that 
  the 
  two 
  groups, 
  though 
  dis- 
  

   tinct, 
  yet 
  are 
  more 
  closely 
  related 
  to 
  each 
  other 
  than 
  to 
  the 
  remain- 
  

   ing 
  known 
  Heteroptera. 
  

  

  How 
  high 
  a 
  rank 
  they 
  should 
  be 
  given 
  in 
  a 
  general 
  scheme 
  of 
  

   classification 
  is 
  a 
  matter 
  impossible 
  to 
  decide 
  satisfactorily 
  until 
  the 
  

   characters 
  of 
  all 
  Heteroptera 
  have 
  been 
  more 
  closely 
  scrutinized 
  and 
  

   evaluated. 
  We 
  content 
  ourselves 
  for 
  the 
  present, 
  therefore, 
  in 
  say- 
  

   ing 
  that 
  the 
  more 
  distinctive 
  characters 
  of 
  the 
  group 
  are: 
  absence 
  

   of 
  metapleural 
  ostioles, 
  possession 
  of 
  only 
  5 
  or 
  6 
  exposed 
  ventral 
  

   segments, 
  and 
  the 
  characteristic 
  texture 
  and 
  venation 
  of 
  the 
  wings. 
  

   The 
  fore 
  wings 
  may 
  be 
  entirely 
  coriaceous 
  or 
  entirely 
  membranous 
  

   but 
  hardly 
  ever 
  are 
  so 
  differentiated 
  in 
  texture 
  that 
  a 
  definite 
  mem- 
  

   brane 
  can 
  be 
  recognized. 
  The 
  definite 
  venation 
  of 
  the 
  basal 
  part 
  of 
  

   the 
  fore 
  wings, 
  and 
  the 
  extension 
  of 
  one 
  or 
  two 
  longitudinal 
  veins 
  

   entirely 
  to 
  the 
  apical 
  margin, 
  are 
  distinctive. 
  The 
  hind 
  wings 
  have 
  

   more 
  or 
  less 
  incised 
  margins, 
  simple 
  longitudinal 
  veins, 
  and 
  so 
  far 
  as 
  

   observed 
  no 
  cross 
  veins 
  (figs. 
  5-7, 
  47). 
  The 
  less 
  significant 
  charac- 
  

   ters 
  of 
  antennae, 
  beak, 
  and 
  tarsi, 
  already 
  mentioned, 
  in 
  connection 
  

   with 
  the 
  small 
  size 
  of 
  the 
  insect's, 
  are 
  useful 
  for 
  ordinary 
  recogni- 
  

   tion 
  of 
  the 
  group. 
  

  

  KEY 
  TO 
  THE 
  SUBFAMILIES 
  

  

  1. 
  Propleurum 
  normal 
  to 
  reduced 
  in 
  size, 
  never 
  swollen 
  anteriorly 
  below 
  eyes; 
  

   coxae 
  greatly 
  developed, 
  occupying 
  pleural 
  spaces 
  so 
  that 
  only 
  the 
  pro- 
  

   plerum 
  is 
  near 
  normal 
  size, 
  metapleurum 
  almost 
  suppressed 
  ; 
  anterior 
  

   width 
  of 
  scutellum 
  over 
  one-half 
  that 
  of 
  hind 
  margin 
  of 
  pronotum 
  ; 
  costa 
  

   of 
  fore 
  wing 
  with 
  a 
  definite 
  fracture 
  in 
  macropterous 
  forms 
  ; 
  vein 
  along 
  

   hind 
  margin 
  of 
  clavus 
  crossing 
  clavus 
  obliquely 
  some 
  distance 
  before 
  

   apex 
  ; 
  one 
  or 
  two 
  free 
  veins 
  in 
  apex 
  of 
  wing 
  of 
  macropterous 
  forms 
  

   (figs. 
  1-4, 
  8-9) 
  ; 
  head 
  usually 
  more 
  porrect 
  and 
  less 
  deeply 
  set 
  into 
  the 
  

  

  