﻿398 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  86 
  

  

  Phorids, 
  in 
  relation 
  to 
  the 
  insect 
  fauna 
  as 
  a 
  whole, 
  are 
  prominent 
  on 
  

   Guam 
  both 
  as 
  to 
  species 
  and 
  individuals. 
  The 
  cosmopolitan 
  Megaselia 
  

   scalaris 
  (Loew) 
  was 
  abundant 
  in 
  all 
  inhabited 
  areas 
  and 
  bred 
  freely 
  in 
  

   such 
  diverse 
  materials 
  as 
  green 
  cornstalks, 
  rotting 
  coconuts, 
  carrion, 
  

   and 
  human 
  excrement. 
  It 
  was 
  almost 
  impossible 
  to 
  keep 
  it 
  from 
  con- 
  

   taminating 
  our 
  cultures 
  of 
  other 
  flies, 
  and 
  it 
  bred 
  freely 
  in 
  fresh 
  stools 
  

   under 
  examination 
  for 
  intestinal 
  parasites 
  by 
  the 
  parasitology 
  labora- 
  

   tory. 
  The 
  highly 
  degenerate 
  Ghonocephalus 
  subglaber 
  had 
  the 
  habit 
  

   of 
  swarming 
  on 
  decaying 
  fruit 
  by 
  thousands, 
  and 
  it 
  could 
  nearly 
  always 
  

   be 
  taken 
  in 
  decaying 
  wood. 
  Collections 
  of 
  rotting 
  shells 
  buried 
  just 
  

   beneath 
  the 
  ground 
  surface 
  furnished 
  breeding 
  material 
  for 
  six 
  species 
  

   of 
  phorids, 
  including 
  two 
  of 
  the 
  wingless 
  genus 
  Puliciphora. 
  

  

  The 
  figures 
  are 
  from 
  drawings 
  by 
  the 
  author. 
  For 
  subjects 
  I 
  used 
  

   specimens 
  in 
  dilute 
  alcohol 
  after 
  softening 
  (but 
  not 
  decolorizing) 
  in 
  

   KOH. 
  The 
  genitalia 
  were 
  drawn 
  from 
  dissected 
  specimens 
  in 
  alcohol 
  

   and 
  checked 
  again 
  for 
  accuracy 
  of 
  details 
  with 
  the 
  same 
  specimens 
  

   mounted 
  in 
  euparol. 
  

  

  The 
  holotypes 
  and 
  allotypes 
  of 
  the 
  new 
  species 
  are 
  in 
  the 
  collection 
  

   of 
  the 
  U. 
  S. 
  National 
  Museum. 
  Paratypes 
  will 
  be 
  deposited 
  in 
  the 
  

   California 
  Academy 
  of 
  Sciences, 
  the 
  collection 
  of 
  the 
  Hawaiian 
  Sugar 
  

   Planters' 
  Association, 
  and 
  the 
  author's 
  collection. 
  

  

  Genus 
  MEGASELIA 
  Rondani 
  

  

  MEGASELIA 
  (MEGASELIA) 
  SETIFEMUR, 
  new 
  species 
  

  

  Figure 
  38 
  

  

  Holotype, 
  male. 
  — 
  Length 
  1.2 
  mm.; 
  length 
  of 
  wing 
  1 
  mm.; 
  frons, 
  

   dorsum 
  of 
  thorax, 
  abdomen, 
  and 
  halteres 
  uniformly 
  piceous-brown 
  ; 
  

   pleura, 
  venter 
  of 
  abdomen, 
  and 
  legs 
  pale 
  testaceous 
  except 
  for 
  darker 
  

   apices 
  of 
  hind 
  fermoa. 
  Head: 
  Frontal 
  bristles 
  thick 
  but 
  not 
  long 
  

   (not 
  more 
  than 
  two-thirds 
  as 
  long 
  as 
  width 
  of 
  frons) 
  ; 
  antiales 
  and 
  

   lower 
  frontals 
  close 
  together 
  and 
  both 
  lower 
  than 
  upper 
  supra-anten- 
  

   nals, 
  which 
  are 
  about 
  twice 
  as 
  long 
  and 
  far 
  apart 
  as 
  the 
  lower 
  supra- 
  

   antennals; 
  cheeks 
  with 
  two 
  strong 
  bristles 
  at 
  lower 
  angle 
  and 
  two 
  

   moderate 
  ones 
  at 
  level 
  of 
  antennal 
  insertion 
  ; 
  frontal 
  hair 
  rather 
  sparse 
  

   and 
  long. 
  Thorax: 
  Dorsal 
  hairs 
  short 
  but 
  strong, 
  becoming 
  sparse 
  

   ap.d 
  bristly 
  toward 
  scutellum; 
  posterior 
  edge 
  of 
  scutum 
  with 
  four 
  

   bristles, 
  the 
  outer 
  ones 
  about 
  one-half 
  longer 
  than 
  the 
  irnier 
  ; 
  scutellum 
  

   with 
  a 
  strong 
  inner, 
  apical 
  pair 
  of 
  bristles 
  about 
  as 
  strong 
  as 
  the 
  outer 
  

   scutal 
  ones, 
  and 
  a 
  very 
  weak 
  outer 
  basal 
  pair 
  less 
  than 
  half 
  as 
  long 
  as 
  

   the 
  inner 
  ones 
  ; 
  pleura 
  bare 
  except 
  for 
  three 
  bristles 
  on 
  ventral 
  margin 
  

   of 
  propleuron 
  ; 
  anterior 
  spiracles 
  included 
  in 
  separate 
  sclerites. 
  Legs 
  : 
  

   Of 
  moderate 
  length, 
  the 
  posterior 
  tibiae 
  and 
  tarsi 
  about 
  as 
  long 
  as 
  

   wings; 
  posterior 
  tibiae 
  with 
  a 
  single 
  dorsal 
  row 
  of 
  setae 
  inside 
  the 
  

   dorsal 
  hair 
  fringe 
  ; 
  posterior 
  metatarsi 
  with 
  two 
  inner 
  bristles 
  some- 
  

  

  