﻿2 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol.67 
  

  

  collections 
  of 
  the 
  Boston 
  Society, 
  Museum 
  of 
  Comparative 
  Zoology, 
  

   and 
  Field 
  Museum 
  of 
  Natural 
  History 
  have 
  been 
  examined 
  also 
  by 
  

   one 
  of 
  the 
  authors 
  during 
  the 
  progress 
  of 
  the 
  work. 
  

  

  THE 
  GROUP 
  TREATED. 
  

   (Subfamily 
  Ploiariinae; 
  Family 
  Reduviidae.) 
  

  

  Insects 
  of 
  the 
  subfamily 
  Ploiariinae, 
  in 
  common 
  with 
  all 
  other 
  

   Reduviidae, 
  have 
  a 
  longitudinal 
  groove 
  between 
  the 
  fore 
  coxae 
  

   which 
  is 
  invariably 
  microscopically 
  transversely 
  striate, 
  and 
  in 
  which 
  

   the 
  tip 
  of 
  the 
  beak 
  generally 
  lies 
  when 
  at 
  rest. 
  This 
  groove 
  is 
  called 
  

   by 
  some 
  writers 
  a 
  " 
  stridulatory 
  groove 
  " 
  but 
  whether 
  it 
  is 
  really 
  so 
  

   we 
  are 
  unable 
  to 
  say. 
  However, 
  it 
  is 
  highly 
  characteristic, 
  as 
  it 
  is 
  

   not 
  present 
  in 
  any 
  other 
  family 
  of 
  Heteroptera 
  known 
  to 
  us 
  except 
  

   the 
  Phymatidae. 
  

  

  Absence 
  of 
  ocelli, 
  and 
  j)resence 
  of 
  anteriorly 
  opening 
  coxal 
  cavities, 
  

   and 
  of 
  usually 
  very 
  elongate 
  fore 
  coxae 
  are 
  the 
  principal 
  distinguish- 
  

   ing 
  characters 
  of 
  the 
  Ploiariinae 
  but 
  neither 
  is 
  sufficient 
  in 
  itself 
  for 
  

   their 
  recognition. 
  The 
  Saicinae 
  also 
  lack 
  ocelli 
  but 
  the 
  fore 
  coxae 
  

   are 
  less 
  elongate 
  than 
  in 
  most 
  Ploiariinae, 
  the 
  beak 
  is 
  armed 
  with 
  

   upwardly 
  directed 
  spines 
  and 
  the 
  lower 
  surface 
  of 
  the 
  head 
  is 
  pro- 
  

   vided 
  with 
  two 
  or 
  more 
  strong 
  bristles. 
  These 
  spines 
  and 
  bristles 
  

   are 
  absent 
  in 
  the 
  Ploiariinae. 
  The 
  Bactrodinae 
  look 
  considerably 
  like 
  

   Ploiariinae 
  but 
  differ 
  structurally 
  from 
  them 
  in 
  characters 
  more 
  im- 
  

   portant 
  even 
  than 
  do 
  the 
  Saicinae. 
  The 
  Bactrodinae 
  have 
  less 
  elon- 
  

   gate 
  coxae 
  than 
  most 
  Ploiariinae, 
  possess 
  ocelli, 
  and 
  the 
  head 
  is 
  in- 
  

   serted 
  not 
  on 
  the 
  front 
  or 
  at 
  most 
  on 
  the 
  anterior 
  margin 
  of 
  the 
  

   prothorax 
  but 
  on 
  the 
  dorsum 
  of 
  that 
  sclerite 
  distinctly 
  posterior 
  to 
  

   the 
  front 
  margin. 
  

  

  Expressing 
  the 
  most 
  characteristic 
  differences 
  between 
  these 
  sub- 
  

   families 
  in 
  key 
  form 
  we 
  have 
  : 
  

  

  1. 
  Anterior 
  coxal 
  cavities 
  opening 
  straight 
  downward 
  ; 
  ocelli 
  none 
  ; 
  underside 
  

  

  of 
  head 
  with 
  downwardly 
  projecting, 
  and 
  beak 
  with 
  upwardly 
  projecting, 
  

  

  bristles 
  or 
  spines 
  Saicinae. 
  

  

  Anterior 
  coxal 
  cavities 
  opening 
  forward 
  and 
  downward 
  ; 
  bead 
  and 
  beak 
  

   without 
  such 
  armature 
  2 
  

  

  2. 
  Ocelli 
  absent 
  ; 
  head 
  scarcely 
  pedicillate, 
  lower 
  anterior 
  border 
  of 
  prothorax 
  

  

  scarcely 
  produced 
  beyond 
  upper 
  margin, 
  on 
  which 
  the 
  head 
  is 
  inserted. 
  

  

  Ploiariinae. 
  

   Ocelli 
  present 
  ; 
  head 
  pedicillate 
  ; 
  lower 
  anterior 
  border 
  of 
  prothorax 
  produced 
  

   distinctly 
  beyond 
  the 
  upper 
  margin, 
  behind 
  which 
  the 
  head 
  is 
  inserted. 
  

  

  Bactrodinae. 
  

  

  The 
  antennae 
  in 
  Ploiariinae 
  are 
  very 
  long 
  and 
  slender, 
  4-seg- 
  

   mented, 
  sometimes 
  with 
  a 
  pseudo-suture 
  near 
  apex 
  of 
  fourth 
  seg- 
  

   ment 
  which 
  is 
  often 
  pointed 
  and 
  more 
  or 
  less 
  angulate 
  or 
  curved; 
  

   the 
  beak 
  is 
  elongate, 
  curved 
  downward 
  and 
  backward, 
  usually 
  

  

  