﻿NEARCTIC 
  PERISCELIDAE 
  — 
  STURTEVANT 
  555 
  

  

  Exotic 
  Periscelidae 
  

  

  Two 
  current 
  keys 
  to 
  the 
  genera 
  of 
  Periscelidae 
  are 
  confused 
  ; 
  the 
  key 
  

   for 
  the 
  North 
  American 
  forms 
  given 
  by 
  Curran 
  (1934, 
  p. 
  323), 
  and 
  the 
  

   key 
  for 
  the 
  genera 
  of 
  the 
  world 
  by 
  Malloch 
  (1932, 
  p. 
  266). 
  My 
  own 
  

   familiarity 
  with 
  exotic 
  forms 
  is 
  limited 
  to 
  a 
  single 
  damaged 
  specimen 
  

   from 
  Colombia 
  in 
  the 
  collection 
  of 
  Cornell 
  University, 
  However, 
  

   this 
  specimen 
  roused 
  my 
  suspicions 
  of 
  the 
  validity 
  of 
  one 
  of 
  the 
  major 
  

   characters 
  used 
  in 
  these 
  keys. 
  As 
  a 
  result, 
  at 
  my 
  request 
  C. 
  W. 
  

   Sabrosky 
  has 
  kindly 
  examined 
  the 
  type 
  specimens 
  of 
  Marbenia 
  

   pecidiaris 
  Malloch, 
  Neoscutops 
  rotundipennis 
  MaUoch, 
  Scutops 
  fasci- 
  

   pennis 
  CoquiUett, 
  and 
  S. 
  maculipennis 
  MaUoch 
  (all 
  USNM) 
  and 
  re- 
  

   ports 
  that 
  in 
  all 
  these 
  the 
  costa 
  reaches 
  only 
  to 
  the 
  third 
  vein. 
  

  

  This 
  is 
  the 
  case 
  also 
  with 
  Periscelis 
  (contrary 
  to 
  Curran's 
  key), 
  

   which 
  means 
  that 
  the 
  first 
  separation 
  given 
  by 
  him 
  is 
  nonexistent 
  if 
  

   Cyamops 
  is 
  removed 
  from 
  the 
  family. 
  A 
  further 
  conclusion 
  then 
  be- 
  

   comes 
  evident: 
  Panamenia 
  Curran 
  is 
  a 
  synonym 
  of 
  Scviops 
  CoquiUett, 
  

   and 
  P. 
  chapmani 
  is 
  doubtfully 
  distinct 
  from 
  ^S. 
  fascipennis 
  CoquiUett. 
  

   The 
  above-mentioned 
  specimen 
  from 
  Colombia 
  is 
  also 
  a 
  Scutops, 
  prob- 
  

   ably 
  best 
  referred 
  to 
  S. 
  fascipennis, 
  though 
  the 
  wing 
  pattern 
  is 
  slightly 
  

   different. 
  

  

  The 
  account 
  by 
  Malloch 
  (1932) 
  is 
  confused 
  in 
  that 
  he 
  says 
  he 
  had 
  

   not 
  seen 
  the 
  European 
  Microperiscelis 
  (Myodris), 
  whereas 
  the 
  genotype 
  

   is 
  annulata, 
  mth 
  which 
  he 
  was 
  familiar. 
  I 
  think 
  it 
  was 
  Periscelis 
  that 
  

   he 
  had 
  not 
  seen. 
  As 
  indicated 
  above, 
  I 
  do 
  not 
  think 
  that 
  Myodris 
  is 
  

   valid. 
  The 
  first 
  separation 
  in 
  MaUoch's 
  key 
  is 
  based 
  on 
  the 
  anterior 
  

   curvature 
  of 
  the 
  auxUiary 
  vein, 
  and 
  he 
  places 
  Scutops 
  in 
  the 
  section 
  

   without 
  such 
  curvature, 
  which 
  is 
  contrary 
  to 
  the 
  notes 
  of 
  Melander 
  

   (1913a, 
  p. 
  167) 
  on 
  the 
  type 
  specimen 
  of 
  S 
  . 
  fascipennis 
  , 
  the 
  genotype. 
  

   It 
  may 
  also 
  be 
  noted 
  that 
  utilization 
  of 
  this 
  character 
  makes 
  Periscelis 
  

   occidentalis, 
  on 
  MaUoch's 
  key, 
  run 
  to 
  the 
  neighborhood 
  of 
  Marbenia, 
  

   a 
  genus 
  that 
  seems 
  to 
  me 
  doubtfully 
  distinct 
  from 
  Periscelis, 
  though 
  I 
  

   am 
  not 
  prepared 
  to 
  insist 
  on 
  the 
  point 
  without 
  seeing 
  Marbenia. 
  

  

  In 
  view 
  of 
  the 
  above 
  it 
  seems 
  desirable 
  to 
  present 
  a 
  revised 
  key 
  to 
  

   the 
  genera 
  of 
  the 
  world, 
  even 
  though 
  I 
  have 
  seen 
  only 
  two 
  of 
  the 
  five. 
  

  

  Key 
  to 
  the 
  genera 
  of 
  Periscelidae 
  of 
  the 
  world 
  

  

  (Modified 
  from 
  Malloch, 
  1932) 
  

  

  1 
  . 
  Face 
  hairy 
  over 
  entire 
  surface 
  2 
  

  

  Face 
  bare 
  in 
  central 
  area 
  3 
  

  

  2. 
  Eyes 
  on 
  conspicuous 
  stalks 
  Diopsosoma 
  Malloch 
  

  

  Eyes 
  not 
  on 
  stalks 
  Neoscutops 
  Malloch 
  

  

  3. 
  Face 
  conspicuously 
  flattened, 
  more 
  or 
  less 
  shield-shaped, 
  and 
  extending 
  forward 
  

  

  below 
  the 
  antennae 
  Scutops 
  CoquiUett 
  

  

  Face 
  without 
  a 
  projecting 
  shield-shaped 
  area 
  4 
  

  

  