﻿ART.l 
  AMERICAN 
  PI.OIARIINAE 
  McATEE 
  AND 
  MALLOCH 
  67 
  

  

  Characters 
  common 
  to 
  all 
  the 
  American 
  species 
  besides 
  those 
  

   mentioned 
  in 
  the 
  generic 
  key 
  are: 
  head 
  lacking 
  spines, 
  prothorax 
  

   (measurements 
  taken 
  on 
  dorsum) 
  twice 
  or 
  more 
  than 
  twice 
  as 
  long 
  

   as 
  meso- 
  and 
  meta-thoraces 
  taken 
  together 
  (even 
  in 
  wingless 
  forms) 
  ; 
  

   the 
  anterior 
  division 
  of 
  prothorax 
  is 
  trumpet-shaped 
  with 
  a 
  low 
  

   tubercle 
  each 
  side 
  in 
  front 
  and 
  expands 
  posteriorly 
  in 
  the 
  winged 
  

   forms 
  into 
  a 
  capacious, 
  inverted, 
  scoop-shaped, 
  highly 
  polished 
  

   portion 
  which 
  completely 
  covers 
  the 
  mesothorax, 
  hind 
  margin 
  usu- 
  

   ally 
  somewhat 
  concave 
  with 
  a 
  slight 
  median 
  swelling, 
  but 
  there 
  are 
  

   notable 
  departures 
  from 
  this 
  character 
  in 
  some 
  species; 
  mesopleura 
  

   and 
  mesosternum 
  highly 
  polished, 
  either 
  subnude 
  or 
  with 
  a 
  bare 
  

   stripe 
  in 
  front 
  of 
  coxa; 
  hind 
  margins 
  of 
  sternites 
  2-6 
  in 
  both 
  sexe? 
  

   more 
  or 
  less 
  emarginate 
  medianly 
  and 
  arcuate 
  laterally, 
  most 
  pro- 
  

   nouncedly 
  so 
  on 
  6; 
  sixth 
  sternite 
  in 
  males 
  visible 
  from 
  above, 
  form- 
  

   ing 
  apparently 
  an 
  almost 
  complete 
  body 
  ring; 
  in 
  most 
  species 
  it 
  is 
  

   overlaid 
  dorsally 
  by 
  a 
  flap-like 
  process 
  of 
  sixth 
  tergite; 
  the 
  ninth 
  

   sternite 
  also 
  is 
  largely 
  exposed 
  dorsally, 
  where 
  it 
  is 
  divided 
  by 
  a 
  

   broad 
  V-shaped 
  cleft 
  open 
  posteriorly 
  (fig. 
  97, 
  and 
  others) 
  ; 
  the 
  

   surface 
  of 
  hypopygial 
  segments 
  is 
  polished; 
  all 
  of 
  the 
  legs 
  and 
  the 
  

   antennae 
  exceed 
  the 
  body 
  in 
  length; 
  antennae 
  of 
  males 
  with 
  abun- 
  

   dant 
  long 
  hairs 
  decreasing 
  in 
  length 
  and 
  erectness 
  distally; 
  espe- 
  

   cially 
  from 
  middle 
  of 
  second 
  segment; 
  wing 
  venation 
  as 
  in 
  figure 
  

   94; 
  fore 
  tibia 
  and 
  tarsus 
  as 
  in 
  figure 
  95. 
  

  

  Coloration 
  in 
  the 
  genus 
  is 
  very 
  uniform, 
  the 
  species 
  being 
  chiefly 
  

   castaneous, 
  darkest 
  on 
  front 
  legs, 
  prothorax, 
  and 
  genitalia; 
  the 
  

   mid 
  and 
  hind 
  trochanters 
  and 
  knees 
  are 
  stramineous, 
  the 
  pale 
  base 
  

   of 
  tibia 
  being 
  more 
  or 
  less 
  interrupted 
  by 
  fuscous; 
  the 
  tegmina 
  and 
  

   wings 
  in 
  most 
  cases 
  are 
  dusky 
  hyaline, 
  whitish 
  at 
  base. 
  

  

  KEY 
  TO 
  THE 
  SPECIES. 
  

  

  Males. 
  

  

  1. 
  Cylindrical 
  part 
  of 
  prothorax 
  silicate 
  in 
  center 
  of 
  dorsum 
  posteriorly 
  ; 
  hind 
  

  

  lobe 
  usually 
  transversely 
  wrinkled 
  anteriorly 
  2 
  

  

  Prothorax 
  without 
  sulcus 
  ; 
  hind 
  lobe 
  usually 
  not 
  distinctly 
  wrinkled 
  8 
  

  

  2. 
  Hind 
  margin 
  of 
  hypopygium 
  more 
  or 
  less 
  sinuate 
  or 
  emarginate 
  in 
  middle 
  

  

  (figs. 
  96, 
  9S, 
  102, 
  104) 
  ; 
  sixth 
  tergite 
  with 
  a 
  longer 
  slender 
  process 
  (figs. 
  

  

  97, 
  108) 
  3 
  

  

  Hind 
  margin 
  of 
  hypopygium 
  practically 
  straight 
  (fig. 
  105) 
  ; 
  7th 
  tergite 
  with 
  

   a 
  shorter, 
  and 
  usually 
  more 
  rounded 
  process 
  (figs. 
  109, 
  112) 
  4 
  

  

  3. 
  Supero-posterior 
  angles 
  of 
  hypopygium 
  strongly 
  produced, 
  projecting 
  when 
  

  

  viewed 
  from 
  behind, 
  much 
  above 
  hind 
  margin 
  ; 
  median 
  process 
  of 
  seventh 
  

   tergite 
  elongate, 
  but 
  falling 
  considerably 
  short 
  of 
  apex 
  of 
  hypopygium 
  (fig. 
  

   97) 
  ; 
  hind 
  margin 
  of 
  pronotum 
  concave, 
  with 
  a 
  slight 
  median 
  swelling. 
  

  

  americana 
  Champion 
  (p. 
  69). 
  

  

  