﻿m 
  1972. 
  yEW 
  DIPTERA 
  OF 
  THE 
  GENVS 
  FASCIA— 
  MALLOCH. 
  629 
  

  

  than 
  its 
  apical 
  width 
  from 
  mouth 
  margin; 
  arista 
  bare; 
  face 
  gra}' 
  

   dusted. 
  Mesonotum 
  with 
  acrostical 
  bristles 
  3-rowed 
  from 
  fourth 
  

   pair, 
  only 
  1 
  pair 
  of 
  presutural 
  dorso-centrals. 
  Abdomen 
  elongate, 
  

   shaped 
  and 
  colored 
  much 
  as 
  in 
  serena 
  Fallen; 
  hypopygium 
  of 
  mod- 
  

   erate 
  size, 
  with 
  apical 
  depression, 
  symmetrical. 
  Fore 
  legs 
  of 
  normal 
  

   shape 
  and 
  bristling. 
  Mid 
  femora 
  very 
  noticeably 
  constricted 
  on 
  

   apical 
  fourth; 
  antero-ventral 
  surface 
  with 
  a 
  row 
  of 
  bristles, 
  the 
  

   first 
  6 
  long 
  and 
  widely 
  spaced, 
  reaching 
  to 
  middle, 
  then 
  there 
  is 
  a 
  

   row 
  of 
  about 
  9 
  much 
  shorter 
  and 
  closer 
  placed 
  bristles, 
  which 
  decrease 
  

   rapidly 
  in 
  size 
  to 
  beginning 
  of 
  constriction, 
  where 
  they 
  cease, 
  the 
  

   last 
  3-4 
  are 
  duplicated, 
  the 
  constricted 
  portion 
  is 
  entirely 
  bare 
  except 
  

   for 
  4-5 
  very 
  minute 
  bristles 
  at 
  apex; 
  the 
  postero-ventral 
  surface 
  has 
  

   much 
  longer, 
  wider-spaced 
  bristles, 
  which 
  become 
  shorter, 
  but 
  

   stronger, 
  from 
  base 
  to 
  constriction, 
  the 
  constricted 
  part 
  bare, 
  and 
  4-5 
  

   bristles 
  rather 
  longer 
  than 
  those 
  on 
  antero-ventral 
  surface 
  at 
  

   apex; 
  posterior 
  surface 
  with 
  long 
  curled 
  bristles. 
  Mid 
  tibia 
  thick- 
  

   ened 
  on 
  apical 
  half, 
  the 
  pubescence 
  on 
  ventral 
  surface 
  distinct 
  on 
  

   thickened 
  portion; 
  bristling, 
  normal; 
  mid 
  metatarsus 
  with 
  a 
  group 
  

   of 
  short 
  bristles 
  forming 
  a 
  fasciculus 
  at 
  base. 
  Hind 
  femora 
  bare 
  on 
  

   ventral 
  surfaces 
  except 
  for 
  1-2 
  bristles 
  on 
  apical 
  third 
  of 
  antero- 
  

   ventral 
  surface, 
  and 
  4-5 
  on 
  same 
  part 
  of 
  postero-ventral 
  surface. 
  

   Hind 
  tibiae 
  with 
  2 
  dorsal, 
  1 
  antero-dorsal, 
  and 
  1 
  antero-ventral 
  

   bristles. 
  Last 
  section 
  of 
  fourth 
  vein 
  barely 
  more 
  than 
  twice 
  as 
  long 
  

   as 
  penultimate 
  section, 
  outer 
  cross-vein 
  at 
  about 
  one-half 
  its 
  own 
  

   length 
  from 
  end 
  of 
  fifth 
  vein. 
  Under 
  scale 
  of 
  calyptrse 
  very 
  slightly 
  

   larger 
  than 
  upper. 
  

  

  Length 
  3-4 
  mm. 
  

  

  Type.— 
  Csit. 
  No. 
  15427, 
  U.S.N.M. 
  

  

  This 
  species 
  has 
  the 
  fasciculus 
  at 
  base 
  of 
  mid 
  metatarsus 
  so 
  weak 
  

   that 
  it 
  is 
  easily 
  overlooked. 
  It, 
  however, 
  belongs 
  to 
  the 
  same 
  group 
  

   as 
  aerea 
  Zetterstedt 
  and 
  armata 
  Meigen. 
  It 
  is 
  more 
  closely 
  allied 
  to 
  

   umbrosa 
  Stein, 
  but 
  the 
  description 
  of 
  that 
  species 
  gives 
  a 
  series 
  of 
  10 
  

   bristles 
  on 
  the 
  posterior 
  femur 
  instead 
  of 
  the 
  4-5 
  which 
  occur 
  in 
  all 
  

   the 
  specimens 
  before 
  me. 
  There 
  are 
  also 
  some 
  minor 
  differences 
  

   between 
  this 
  species 
  and 
  the 
  description 
  given 
  by 
  Stein 
  for 
  umhrosa, 
  

   which 
  prevent 
  me 
  identifying 
  this 
  species 
  with 
  his. 
  

  

  Type-locality. 
  — 
  White 
  Mountains, 
  New 
  Hampshire 
  (Morrison 
  0, 
  

   three 
  males, 
  

  

  Ainsworth, 
  British 
  Columbia, 
  one 
  male 
  (R, 
  P. 
  Currie); 
  Humboldt 
  

   County, 
  California, 
  one 
  male 
  (H. 
  S, 
  Barber). 
  The 
  last-mentioned 
  

   two 
  specimens 
  have 
  the 
  halteres 
  yellowish, 
  which 
  is 
  probably 
  

   due 
  to 
  their 
  being 
  rather 
  immature, 
  A 
  number 
  of 
  specimens 
  

   which 
  are 
  standing 
  in 
  the 
  collection 
  as 
  Homalomyia 
  jlavibasis 
  Stein, 
  

   belong 
  to 
  setMops; 
  the 
  localities 
  are 
  Virgins 
  Bay, 
  Popolf 
  Island, 
  Muirs 
  

   Inlet, 
  and 
  Sitka, 
  Alaska 
  (Harriman 
  Alaska 
  Expedition, 
  T. 
  Kincaid). 
  

  

  