﻿PROCEEDINGS 
  OF 
  THE 
  UNITED 
  STATES 
  NATIONAL 
  MUSEUM 
  

  

  SMITHSONIAN 
  INSTITUTION 
  

   U. 
  S. 
  NATIONAL 
  MUSEUM 
  

  

  VoL 
  103 
  Wwhington 
  : 
  1954 
  No. 
  3332 
  

  

  NEARCTIC 
  FLIES 
  OF 
  THE 
  FAMILY 
  PERISCELIDAE 
  

  

  (DIPTERA) 
  AND 
  CERTAIN 
  ANTHOMYZIDAE 
  

  

  REFERRED 
  TO 
  THE 
  FAMILY 
  

  

  By 
  A. 
  H. 
  Sturtevant 
  ^ 
  

  

  The 
  family 
  Periscelidae 
  was 
  not 
  recognized 
  by 
  earlier 
  authors, 
  its 
  

   species 
  being 
  assigned 
  to 
  varying 
  ones 
  of 
  the 
  other 
  acalypterate 
  

   families. 
  Even 
  when 
  it 
  is 
  recognized 
  as 
  a 
  distinct 
  group 
  there 
  is 
  no 
  

   agreement 
  as 
  to 
  what 
  genera 
  should 
  be 
  included. 
  My 
  own 
  studies 
  

   have 
  convinced 
  me 
  that 
  the 
  family 
  is 
  best 
  limited 
  (as 
  concerns 
  the 
  

   Nearctic 
  region) 
  to 
  the 
  single 
  genus 
  Periscelis. 
  (Nearctic 
  species 
  

   have 
  been 
  assigned 
  to 
  the 
  genera 
  Microperiscelis 
  and 
  Sphyroperiscelis, 
  

   not 
  here 
  recognized 
  as 
  distinct.) 
  

  

  There 
  are 
  included 
  here 
  a 
  few 
  notes 
  on 
  exotic 
  Periscelidae, 
  with 
  a 
  

   list 
  (including 
  references) 
  of 
  the 
  known 
  species 
  of 
  the 
  world 
  and 
  a 
  key 
  

   to 
  the 
  known 
  genera. 
  I 
  have 
  included 
  Cyamops 
  since 
  it 
  has 
  been 
  

   included 
  in 
  recent 
  accounts. 
  I 
  have 
  also 
  included 
  Stenomicra, 
  which 
  

   has 
  been 
  referred 
  here 
  but 
  neglected 
  by 
  some 
  recent 
  students. 
  In 
  order 
  

   to 
  place 
  these 
  two 
  genera 
  I 
  have 
  added 
  a 
  discussion 
  of 
  the 
  Anthomy- 
  

   zidae, 
  with 
  a 
  key 
  to 
  the 
  Nearctic 
  genera 
  of 
  that 
  family. 
  

  

  The 
  following 
  abbreviations 
  have 
  been 
  used 
  in 
  designating 
  locations 
  

   of 
  type 
  specimens: 
  AMNH, 
  for 
  American 
  Museum 
  of 
  Natural 
  History; 
  

   and 
  USNM, 
  for 
  U. 
  S. 
  National 
  Museum. 
  

  

  I 
  California 
  Institute 
  of 
  Technology, 
  Pasadena, 
  Calif. 
  

  

  290839—54- 
  551 
  

  

  