﻿DESCRIPTIONS 
  OF 
  NEW 
  SPECIES 
  OF 
  MIERICAN 
  FLIES 
  OF 
  

   THE 
  FAMILY 
  BORBORID^. 
  

  

  By 
  J. 
  R. 
  Malloch, 
  

  

  Of 
  the 
  Bureau 
  of 
  Entomology 
  , 
  United 
  States 
  Department 
  of 
  Agriculture. 
  

  

  The 
  Borboridse 
  are 
  small 
  flies 
  which 
  have 
  been 
  much 
  neglected 
  by 
  

   systematists. 
  Even 
  in 
  Europe, 
  where 
  the 
  Diptera 
  have 
  been 
  most 
  

   thoroughly 
  studied, 
  the 
  species 
  of 
  this 
  family 
  are 
  but 
  imperfectly 
  

   known. 
  When 
  carefully 
  studied 
  the 
  species 
  of 
  this 
  group 
  present 
  

   good 
  generic 
  and 
  specific 
  characters, 
  and 
  it 
  is 
  hoped 
  that 
  the 
  follow- 
  

   ing 
  descriptions 
  will 
  contribute 
  to 
  a 
  better 
  understanding 
  of 
  the 
  

   group. 
  

  

  APTILOTUS 
  BOREALIS, 
  new 
  species. 
  

  

  Female. 
  — 
  Black, 
  shining; 
  frons 
  subopaque; 
  lateral, 
  ocellar 
  and 
  

   vertical 
  bristles 
  as 
  in 
  the 
  species 
  of 
  Limosina, 
  center 
  rows 
  consisting 
  

   of 
  one 
  strong, 
  cruciate 
  pair 
  and 
  an 
  upper, 
  and 
  lower 
  pair 
  of 
  much 
  

   smaller, 
  hairlike 
  bristles, 
  frons 
  as 
  long 
  in 
  center 
  as 
  three-fourths 
  its 
  

   central 
  breadth, 
  anterior 
  outline 
  centrally 
  produced, 
  basal 
  joint 
  of 
  

   antennae 
  black, 
  apical 
  joint 
  brown, 
  the 
  bristles 
  on 
  basal 
  joint 
  strong, 
  

   pubescence 
  on 
  apical 
  joint 
  pale, 
  arista 
  brown, 
  pubescent, 
  one-third 
  

   longer 
  than 
  breadth 
  of 
  frons 
  at 
  center, 
  face 
  black, 
  subopaque, 
  raised 
  

   almost 
  ridgelike 
  longitudinally 
  in 
  center, 
  in 
  profile 
  concave, 
  the 
  

   mouth 
  margin 
  produced, 
  labrum 
  protruding, 
  mouth 
  opening 
  large, 
  

   palpi 
  small, 
  proboscis 
  not 
  much 
  reduced 
  in 
  size, 
  cheeks 
  black, 
  opaque, 
  

   below 
  center 
  of 
  eye 
  more 
  than 
  half 
  as 
  high 
  as 
  eye 
  height, 
  anterior 
  

   bristle 
  strong, 
  posterior 
  bristles 
  weak 
  and 
  hairlike; 
  thorax 
  short, 
  sub- 
  

   quadrate, 
  very 
  slightly 
  longer 
  and 
  narrower 
  than 
  head, 
  bristles 
  on 
  

   mcsonotum 
  of 
  moderate 
  length, 
  in 
  regular 
  rows, 
  one 
  distinct 
  pair 
  of 
  

   dorso-central 
  macrochaetse, 
  a 
  very 
  strong 
  bristle 
  on 
  the 
  lateral 
  mar- 
  

   gins 
  at 
  posterior 
  fourth, 
  lateral 
  margins 
  with 
  several 
  weaker 
  bristles 
  

   antcriorl)', 
  pleurae 
  opaque 
  black, 
  the 
  pleural 
  bristle, 
  so 
  very 
  conspicu- 
  

   ous 
  in 
  Limosina, 
  very 
  much 
  reduced 
  in 
  size, 
  scutellum 
  two-fifths 
  as 
  

   long 
  as 
  mesonotum, 
  distinctly 
  narrower, 
  regularly 
  rounded, 
  with 
  four 
  

   marginal, 
  subequal, 
  equidistant 
  bristles, 
  five 
  visible 
  abdominal 
  dorsal 
  

   segments, 
  the 
  basal 
  segment 
  as 
  in 
  Borborus 
  and 
  Limosina, 
  very 
  short 
  

  

  Proceedings 
  U. 
  S. 
  National 
  Museum, 
  Vol. 
  44-No. 
  1958. 
  

  

  361 
  

  

  