﻿art. 
  1 
  AMERICAN 
  PLOIARIINAE 
  McATEE 
  AND 
  MALLOCH 
  91 
  

  

  nately 
  been 
  able 
  through 
  the 
  kindness 
  of 
  Dr. 
  E. 
  Bergroth 
  to 
  examine 
  

   the 
  types 
  of 
  his 
  species, 
  aid 
  which 
  has 
  been 
  of 
  the 
  utmost 
  value 
  in 
  

   the 
  study 
  of 
  the 
  present 
  genus. 
  

  

  However, 
  inability 
  to 
  inspect 
  other 
  type 
  specimens 
  can 
  not 
  be 
  per- 
  

   mitted 
  to 
  prevent 
  a 
  revision 
  of 
  the 
  genus 
  which 
  proves 
  to 
  be 
  richer 
  in 
  

   species 
  than 
  has 
  previously 
  been 
  suspected. 
  This 
  latter 
  fact 
  in 
  itself 
  

   insures 
  that 
  few 
  of 
  our 
  species 
  will 
  prove 
  identical 
  with 
  the 
  older 
  

   ones, 
  while 
  the 
  total 
  to 
  be 
  discovered 
  in 
  neotropical 
  regions 
  can 
  only 
  

   be 
  indicated 
  by 
  an 
  estimate 
  so 
  large 
  that 
  it 
  would 
  be 
  considered 
  ab- 
  

   surd 
  by 
  many 
  entomologists. 
  

  

  KEY 
  TO 
  THE 
  SPECIES. 
  

  

  Males. 
  

  

  1. 
  Mesothorax 
  distinctly 
  longer 
  than 
  prothorax 
  ; 
  shape 
  of 
  abdomen 
  various- 
  2 
  

   Mesothorax 
  little 
  if 
  any 
  longer 
  than 
  prothorax 
  ; 
  abdomen 
  gradually 
  widen- 
  

   ing 
  from 
  base 
  20 
  

  

  2. 
  Abdomen 
  with 
  an 
  abrupt 
  bulbous 
  swelling 
  behind 
  middle 
  (figs. 
  196, 
  

  

  201) 
  3 
  

  

  Abdomen 
  without 
  bulbous 
  swelling 
  (figs. 
  169, 
  210) 
  14 
  

  

  3. 
  Spine 
  between 
  antennae 
  well 
  developed, 
  acute 
  ; 
  head 
  and 
  prothorax 
  usually 
  

  

  distinctly 
  granulose 
  ; 
  elaspers 
  of 
  hypopygium 
  with 
  upper 
  and 
  lower 
  mar- 
  

   gins 
  in 
  most 
  species 
  without 
  a 
  rounded 
  subapical 
  notch 
  above 
  or 
  below 
  ; 
  

  

  metathorax 
  usually 
  much 
  attenuated 
  anteriorly 
  4 
  

  

  Spine 
  between 
  antennae 
  not 
  developed, 
  a 
  mere 
  wart, 
  blunt 
  ; 
  head 
  and 
  pro- 
  

   thorax 
  but 
  little 
  granulose 
  ; 
  elaspers 
  of 
  hypopygium 
  long, 
  obtriangular 
  

   with 
  at 
  least 
  the 
  upper 
  margin 
  notched 
  13 
  

  

  4. 
  Hypopygium 
  with 
  a 
  large 
  apical 
  hook 
  like 
  process 
  which 
  has 
  an 
  emargina- 
  

  

  tion 
  or 
  concavity 
  on 
  each 
  side 
  of 
  hook, 
  not 
  entirely 
  filled 
  by 
  the 
  elaspers 
  

  

  (figs. 
  193, 
  194, 
  200) 
  12 
  

  

  Hypopygium 
  with 
  a 
  small 
  apical 
  process 
  which 
  is 
  visible 
  only 
  under 
  high 
  

   magnification, 
  the 
  upper 
  margin 
  of 
  hypopygium 
  but 
  little 
  concave, 
  the 
  

   elaspers 
  entirely 
  filling 
  the 
  space 
  between 
  the 
  margin 
  and 
  the 
  process 
  

   (fig. 
  197) 
  5 
  

  

  5. 
  Fifth 
  tergite 
  bearing 
  a 
  pair 
  of 
  strongly 
  divergent 
  long 
  conical 
  horns, 
  equal 
  in 
  

  

  length 
  to 
  entire 
  bulbosity 
  (fig. 
  205) 
  mirabilis, 
  new 
  species 
  (p. 
  124). 
  

  

  Fifth 
  tergite 
  without 
  such 
  horns 
  6 
  

  

  6. 
  Seventh 
  tergite 
  short, 
  sixth 
  entirely 
  incorporated 
  into 
  the 
  bulbosity 
  which 
  

  

  thus 
  appears 
  almost 
  terminal 
  (fig. 
  201) 
  7 
  

  

  Seventh 
  tergite 
  long, 
  sixth 
  not 
  wholly 
  incorporated 
  into 
  bulbosity 
  which 
  is 
  

   distinctly 
  subterminal 
  8 
  

  

  7. 
  Sixth 
  tergite 
  more 
  than 
  half 
  as 
  long 
  as 
  fifth, 
  provided 
  with 
  a 
  smaller 
  ele- 
  

  

  vation 
  similar 
  in 
  shape 
  to 
  that 
  of 
  fifth 
  (fig. 
  201). 
  

  

  filiventris 
  Spinola 
  (p. 
  123). 
  

   Sixth 
  tergite 
  less 
  than 
  half 
  as 
  long 
  as 
  fifth, 
  without 
  elevations. 
  

  

  atriclava 
  Bergroth 
  (p. 
  123). 
  

  

  8. 
  Widest 
  part 
  of 
  bulbosity 
  in 
  fourth 
  segment 
  ; 
  top 
  of 
  abdomen 
  with 
  2 
  distinct 
  

  

  longitudinal 
  lines 
  of 
  gray 
  hairs 
  globifera 
  Bergroth 
  (p. 
  110). 
  

  

  Widest 
  part 
  of 
  bulbosity 
  in 
  fifth 
  segment 
  9 
  

  

  9. 
  Fifth 
  tergite 
  lacking 
  subangulate 
  ridged 
  elevations; 
  sixth 
  trisinuate 
  poste- 
  

  

  riorly 
  claviventris 
  Bergroth 
  (p. 
  109). 
  

  

  Fifth 
  tergite 
  with 
  subangulate 
  ridged 
  elevations; 
  sixth 
  slightly 
  convex 
  

   posteriorly 
  10 
  

  

  