﻿368 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  vol.44. 
  

  

  dusted, 
  labrum 
  distinctly 
  protruding, 
  shining, 
  with 
  slight 
  dusting, 
  

   antennae 
  black, 
  basal 
  joint 
  with 
  numerous 
  hau's 
  and 
  no 
  longer 
  bristle 
  

   above, 
  third 
  joint 
  large, 
  more 
  than 
  twice 
  as 
  large 
  as 
  basal 
  joint, 
  

   rounded, 
  with 
  very 
  close, 
  short 
  pilosity, 
  which 
  is 
  pale 
  yellowish 
  in 
  

   color, 
  arista 
  not 
  longer 
  than 
  breadth 
  of 
  frons, 
  distinctly, 
  but 
  sparsely 
  

   pubescent, 
  cheeks 
  below 
  eyes 
  glossy 
  black, 
  lower 
  hall' 
  opaque, 
  anterior 
  

   bristle 
  very 
  long, 
  those 
  posterior 
  to 
  it 
  gradually 
  decreasing 
  in 
  length, 
  

   cheelvs 
  from 
  mouth 
  margin 
  to 
  lowest 
  part 
  of 
  eyo 
  more 
  than 
  half 
  as 
  

   high 
  as 
  eye 
  — 
  taking 
  both 
  at 
  center 
  of 
  eye 
  — 
  the 
  c^^e 
  is 
  very 
  small 
  as 
  

   compared 
  with 
  hrevisetns, 
  in 
  which 
  species 
  the 
  jowl, 
  or 
  cheek, 
  is 
  not 
  

   more 
  than 
  one-third 
  as 
  high 
  as 
  eye 
  at 
  center; 
  mcsonotum 
  unstripcd, 
  

   slightly 
  gray 
  -dusted, 
  with 
  four 
  regular 
  rows 
  of 
  dorsal 
  setulae, 
  which 
  

   are 
  rather 
  long 
  but 
  hair-like, 
  pleurae 
  glossy 
  black 
  on 
  lower 
  portion, 
  

   subopaque 
  above, 
  scutellum 
  with 
  four 
  moderately 
  long, 
  marginal 
  

   bristles, 
  abdomen 
  shining, 
  basal 
  segment 
  in 
  male 
  as 
  long 
  as 
  next 
  two, 
  

   second 
  to 
  fourth 
  subequal, 
  all 
  segments 
  with 
  lateral, 
  and 
  last 
  two 
  with 
  

   posterior, 
  marginal, 
  hair-like 
  bristles, 
  male 
  hypopygium 
  very 
  large, 
  

   knob-like, 
  with 
  complicated 
  ventral 
  processes, 
  and 
  with 
  numerous 
  

   hairs 
  on 
  the 
  dorsal 
  plate, 
  female 
  abdomen 
  with 
  basal 
  segment 
  only 
  as 
  

   long 
  as 
  one 
  and 
  one-half 
  times 
  second, 
  the 
  others 
  subequal, 
  bristled 
  as 
  

   in 
  male; 
  legs 
  black, 
  covered 
  with 
  very 
  numerous 
  black 
  hairs, 
  fore 
  

   femora 
  dilated, 
  mid-femora 
  normal, 
  with 
  one 
  bristle 
  distinct 
  fi-om 
  

   the 
  hairs 
  at 
  near 
  apical 
  third 
  on 
  anterior 
  surface, 
  mid-tibise 
  with 
  a 
  

   similar 
  bristle 
  situated 
  as 
  on 
  femora, 
  two 
  preapical 
  bristles 
  — 
  one 
  

   antero- 
  and 
  one 
  postero-dorsal 
  — 
  as 
  well 
  as 
  the 
  apical 
  spurs, 
  hind 
  

   femora 
  normal 
  in 
  size, 
  with 
  2-3 
  bristles 
  more 
  distinct 
  than 
  the 
  hairs 
  

   on 
  the 
  center 
  of 
  the 
  dorsal 
  surface, 
  hind 
  tibiae 
  slightly 
  shorter 
  than 
  

   femora, 
  with 
  one 
  long 
  doi-sal 
  bristle 
  at 
  apical 
  fourth, 
  one 
  on 
  almost 
  

   the 
  ventral 
  surface 
  at 
  near 
  the 
  apical 
  third, 
  and 
  a 
  long 
  thorn-like 
  

   curved 
  apical 
  spine, 
  basal 
  joint 
  of 
  hind 
  tarsi 
  much 
  dilated, 
  two- 
  

   thirds 
  as 
  long 
  as 
  second 
  basal, 
  which 
  is 
  less 
  distinctly 
  dilated 
  than 
  

   basal; 
  wings 
  yellowish-brown, 
  veins 
  brown, 
  from 
  humeral 
  vein 
  to 
  

   end 
  of 
  first 
  vein 
  one-third 
  as 
  long 
  as 
  from 
  end 
  of 
  first 
  vein 
  to 
  end 
  of 
  

   second 
  and 
  distinctly 
  longer 
  than 
  from 
  end 
  of 
  second 
  to 
  end 
  of 
  

   third; 
  small 
  cross 
  vein 
  not 
  upright 
  but 
  sloped 
  outward 
  at 
  upper 
  

   extremity, 
  distinctly 
  beyond 
  end 
  of 
  first 
  vein 
  and 
  at 
  less 
  than 
  one- 
  

   third 
  from 
  base 
  of 
  discal 
  cell, 
  third 
  and 
  fourth 
  veins 
  slightly 
  con- 
  

   vergent 
  toward 
  apices, 
  fifth 
  vein 
  reaching 
  half 
  way 
  from 
  cross 
  vein 
  

   to 
  wing 
  margin; 
  halteres 
  dusk}^ 
  yellow. 
  

  

  Length, 
  2 
  mm. 
  

  

  One 
  female, 
  Ungava 
  Bay, 
  one 
  female 
  and 
  one 
  male. 
  Fort 
  Chimo, 
  

   Labrador 
  (L. 
  M. 
  Turner). 
  

  

  A 
  male 
  from 
  the 
  District 
  of 
  Columbia, 
  standing 
  as 
  vitnpennis 
  

   Meigen 
  in 
  collection, 
  may 
  belong 
  to 
  this 
  species. 
  It 
  diiTers 
  from 
  the 
  

   above 
  description 
  in 
  having 
  the 
  tibiae 
  and 
  tarsi 
  yellow 
  and 
  seems 
  to 
  

  

  