﻿NEARCTIC 
  PERISCELIDAE 
  — 
  STURTEVANT 
  557 
  

  

  to 
  first 
  vein; 
  distal 
  costal 
  break 
  represented 
  at 
  least 
  by 
  a 
  definite 
  

   weakening; 
  tibiae 
  without 
  preapicals. 
  

  

  The 
  antennal 
  structm-e 
  suggests 
  that 
  of 
  the 
  Periscelidae, 
  but 
  that 
  

   family 
  is 
  easily 
  distinguished 
  from 
  the 
  Anthomyzidae 
  by 
  its 
  long 
  first 
  

   vein; 
  complete 
  absence 
  of 
  distal 
  costal 
  break; 
  divergent 
  postverticals. 
  

  

  The 
  members 
  of 
  tliis 
  family 
  are 
  sometimes 
  treated 
  as 
  belonging 
  to 
  

   the 
  Opomyzidae, 
  which 
  differ 
  in 
  having 
  presutural 
  dorsocentrals, 
  

   hairy 
  mesopleura, 
  divergent 
  postverticals, 
  and 
  no 
  true 
  vibrissae. 
  

   The 
  only 
  Nearctic 
  genus 
  of 
  Opomyzidae 
  known 
  to 
  me 
  is 
  Geomyza, 
  

   which 
  has 
  a 
  large 
  oral 
  bristle 
  that 
  might 
  be 
  considered 
  a 
  vibrissa 
  were 
  

   it 
  not 
  situated 
  some 
  distance 
  behind 
  the 
  anterior 
  end 
  of 
  the 
  row 
  of 
  

   oral 
  hairs. 
  The 
  remaining 
  genera 
  listed 
  by 
  Curran 
  (1934) 
  under 
  this 
  

   family 
  and 
  not 
  included 
  in 
  the 
  key 
  below 
  make 
  up 
  the 
  family 
  Tethini- 
  

   dae. 
  (See 
  Melander, 
  1951, 
  p. 
  187.) 
  

  

  Key 
  to 
  the 
  Nearctic 
  genera 
  of 
  Anthomyzidae 
  

  

  1. 
  Upper 
  occiput 
  convex; 
  posterior 
  margin 
  of 
  wing 
  usually 
  absent, 
  making 
  wing 
  

  

  very 
  narrow 
  Mutiloptera 
  Coquillett 
  

  

  Upper 
  occiput 
  concave; 
  wing 
  complete 
  except 
  sometimes 
  with 
  reduced 
  anal 
  

   angle 
  2 
  

  

  2. 
  Postverticals 
  small 
  ; 
  2 
  or 
  3 
  reclinate 
  orbitals 
  3 
  

  

  Postverticals 
  absent; 
  usually 
  only 
  one 
  conspicuous 
  reclinate 
  orbital; 
  proclinate 
  

   orbitals 
  present 
  or 
  absent 
  4 
  

  

  3. 
  Second 
  vein 
  sinuate; 
  marginal 
  cell 
  at 
  level 
  of 
  posterior 
  crossvein 
  less 
  than 
  

  

  half 
  width 
  of 
  submarginal 
  Ischnomyia 
  Loew 
  

  

  Second 
  vein 
  greatly 
  curved; 
  marginal 
  cell 
  at 
  level 
  of 
  posterior 
  crossvein 
  more 
  

   than 
  half 
  width 
  of 
  submarginal 
  Anthomyza 
  Fallen 
  

  

  4. 
  Yellow 
  species; 
  anal 
  angle 
  of 
  wing 
  rudimentary 
  Stenoniicra 
  Coquillett 
  

  

  Blackish; 
  anal 
  angle 
  well 
  developed 
  5 
  

  

  5. 
  Arista 
  pubescent 
  or 
  short-plumose 
  (branches 
  not 
  longer 
  than 
  length 
  of 
  third 
  

  

  antennal 
  segment); 
  no 
  comb 
  of 
  short 
  spines 
  on 
  first 
  femur; 
  no 
  proclinate 
  

  

  orbital 
  Mumetopia 
  Melander 
  

  

  Arista 
  long 
  plumose 
  (branches 
  longer 
  than 
  length 
  of 
  third 
  antennal 
  segment) 
  ; 
  

   a 
  comb 
  of 
  short, 
  close-set 
  spines 
  on 
  distal 
  inner 
  flexor 
  surface 
  of 
  first 
  femur; 
  

   a 
  proclinate 
  orbital 
  Cyamops 
  Melander 
  

  

  I 
  have 
  not 
  seen 
  Mutiloptera, 
  which 
  is 
  perhaps 
  an 
  opomyzid. 
  Of 
  

   the 
  other 
  genera, 
  the 
  above 
  key 
  is 
  based 
  on 
  examination 
  of 
  the 
  indi- 
  

   cated 
  number 
  of 
  species 
  (some 
  Neotropical 
  or 
  Palearctic) 
  of 
  the 
  follow- 
  

   ing 
  genera: 
  Ischnomyia, 
  2; 
  Anthomyza, 
  6; 
  Stenomicra, 
  1; 
  Mumetopia, 
  

   3; 
  Cyamops, 
  2. 
  

  

  Genus 
  Cyamops 
  Melander, 
  1913 
  

  

  Brues 
  and 
  Melander 
  (1932) 
  and 
  Curran 
  (1934) 
  included 
  Cyamops 
  

   in 
  the 
  Periscelidae. 
  This 
  genus 
  was 
  described 
  as 
  a 
  "geomyzid," 
  and 
  

   seems 
  to 
  me 
  best 
  placed 
  in 
  the 
  Anthomyzidae, 
  close 
  to 
  Mumetopia. 
  

  

  In 
  the 
  keys 
  iu 
  both 
  the 
  above 
  works 
  the 
  Periscelidae 
  are 
  separated 
  

   from 
  the 
  Anthomyzidae 
  (treated 
  as 
  part 
  of 
  the 
  Opomyzidae 
  by 
  

  

  