﻿6 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol.. 
  67 
  

  

  KEY 
  TO 
  THE 
  AMERICAN 
  SPECIES 
  OP 
  OSOIUUS 
  LATREILLE 
  

  

  1. 
  Thorax 
  wider 
  posteriorly. 
  The 
  labrum 
  asymmetrical. 
  Length 
  12-15 
  mm. 
  

  

  * 
  asymmetricus 
  Fauvel. 
  

   Thorax 
  not 
  wider 
  posteriorly. 
  The 
  labrum 
  not 
  asymmetrical 
  2 
  

  

  2. 
  Body 
  very 
  densely 
  and 
  conspicuously 
  pubescent. 
  The 
  thorax 
  longer 
  than 
  

  

  wide. 
  Length 
  S 
  mm 
  * 
  hirtulus 
  Fauvel. 
  

  

  Body 
  not 
  conspicuously 
  pubescent 
  3 
  

  

  3. 
  Thorax 
  without 
  a 
  side 
  margin. 
  Head 
  very 
  densely 
  and 
  strongly 
  punctate. 
  

  

  The 
  elytra 
  rugulose. 
  Length 
  4.5-5 
  mm 
  * 
  rugipennis 
  Bernhauer. 
  

  

  Thorax 
  with 
  a 
  side 
  margin 
  4 
  

  

  4. 
  Anterior 
  angles 
  of 
  the 
  clypeus 
  conspicuously 
  produced 
  5 
  

  

  Anterior 
  angles 
  of 
  the 
  clypeus 
  not 
  conspicuously 
  produced 
  7 
  

  

  5. 
  Head 
  alutaceous 
  and 
  subopaque 
  anteriorly, 
  with 
  a 
  definitely 
  marked 
  pos- 
  

  

  terior, 
  highly 
  polished 
  area. 
  The 
  thorax 
  rather 
  densely 
  and 
  finely 
  punc- 
  

   tate, 
  somewhat 
  broader 
  than 
  long. 
  Length 
  6.5 
  mm_* 
  dentatus 
  Bernhauer. 
  

   Head 
  without 
  a 
  sharply 
  defined, 
  posterior, 
  highly 
  polished 
  area 
  6 
  

  

  6. 
  Thorax 
  more 
  coarsely 
  and 
  densely 
  punctate. 
  The 
  abdominal 
  segments 
  

  

  with 
  distinct 
  and 
  rather 
  dense 
  punctuation 
  on 
  the 
  lateral 
  declivity. 
  

  

  Length 
  9.5 
  mm 
  hubbardi, 
  new 
  species 
  

  

  Thorax 
  more 
  finely 
  and 
  sparsely 
  punctate. 
  The 
  abdominal 
  segments 
  with- 
  

   out 
  punctuation 
  on 
  the 
  lateral 
  declivity. 
  Length 
  12-14 
  mm 
  ater 
  Perty. 
  

  

  7. 
  Thorax 
  distinctly 
  longer 
  than 
  broad. 
  The 
  head, 
  thorax, 
  elytra 
  and 
  abdomen 
  

  

  strongly 
  and 
  rather 
  densely 
  punctured. 
  Length 
  3.5 
  mm. 
  

  

  eggersi 
  Bernhauer. 
  

   Thorax 
  not 
  distinctly 
  longer 
  than 
  broad 
  8 
  

  

  8. 
  Thorax 
  with 
  the 
  lateral 
  margins 
  fine 
  throughout 
  9 
  

  

  Thorax 
  with 
  the 
  lateral 
  margins 
  broader 
  and 
  more 
  strongly 
  reflexed 
  

  

  posteriorly 
  42 
  

  

  9. 
  Dorsal 
  segments 
  of 
  the 
  abdomen 
  more 
  or 
  less 
  densely 
  and 
  conspicuous] 
  

  

  punctured 
  10 
  

  

  Dorsal 
  segments 
  of 
  the 
  abdomen 
  more 
  or 
  less 
  sparsely 
  punctured 
  32 
  

  

  10. 
  Clypeus 
  strongly 
  emarginate 
  politus 
  LeConte. 
  

  

  Clypeus 
  truncate 
  or 
  subtruncate 
  11 
  

  

  11. 
  Head 
  distinctly 
  narrower 
  than 
  the 
  thorax. 
  The 
  thorax 
  rather 
  finely 
  

  

  punctate. 
  The 
  sides 
  parallel 
  to 
  behind 
  the 
  middle, 
  with 
  the 
  anterior 
  

   angles 
  prominent. 
  Abdomen 
  without 
  a 
  median 
  smooth 
  stripe. 
  Length 
  

  

  nun 
  parviceps. 
  new 
  species. 
  

  

  Head 
  not 
  narrower 
  than 
  the 
  thorax 
  12 
  

  

  12. 
  Head 
  scabro-rugulose 
  laterally 
  in 
  front 
  of 
  the 
  eyes. 
  The 
  thorax 
  with 
  base 
  

  

  and 
  apex 
  nearly 
  equal, 
  scarcely 
  broader 
  than 
  lung. 
  The 
  elytra 
  indis- 
  

   tinctly 
  punctate. 
  The 
  abdomen 
  with 
  a 
  median 
  smooth 
  stripe. 
  Length 
  

  

  5-0 
  nun 
  * 
  frater 
  Lynch. 
  

  

  Head 
  not 
  scabro-rugulose 
  in 
  front 
  of 
  the 
  eyes 
  13 
  

  

  13. 
  Front 
  of 
  the 
  head 
  more 
  distinctly 
  alutaceous 
  anteriorly 
  14 
  

  

  Front 
  of 
  the 
  head 
  not 
  distinctly 
  alutaceous 
  though 
  sometimes 
  coarsely 
  and 
  

  

  closely 
  punctured 
  22 
  

  

  14. 
  Elytra 
  strongly 
  rugose. 
  Length 
  5.5 
  mm 
  * 
  argentinus 
  Bernhauer. 
  

  

  Elytra 
  more 
  or 
  less 
  sparsely 
  and 
  indistinctly 
  punctate 
  15 
  

  

  15. 
  Size 
  larger. 
  Form 
  broader. 
  Posterior 
  angles 
  of 
  the 
  thorax 
  less 
  obtuse. 
  

  

  Length 
  8-9 
  mm 
  * 
  crassus 
  Sharp. 
  

  

  Size 
  smaller. 
  From 
  narrower, 
  not 
  more 
  than 
  7 
  mm 
  16 
  

  

  