﻿50 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol.. 
  67 
  

  

  into 
  strange 
  country; 
  while 
  with 
  a 
  simple 
  key, 
  after 
  following 
  an 
  

   easy 
  lead 
  to 
  the 
  genus, 
  even 
  if 
  he 
  does 
  find 
  a 
  key 
  grouping 
  a 
  con- 
  

   siderable 
  number 
  of 
  related 
  forms, 
  he 
  will 
  at 
  least 
  be 
  near 
  his 
  destina- 
  

   tion 
  (that 
  is, 
  among 
  forms 
  truly 
  related 
  to 
  that 
  in 
  hand). 
  Winged 
  

   and 
  apterous 
  specimens 
  occur 
  in 
  the 
  same 
  species 
  of 
  Ploiaria, 
  and 
  i( 
  

   requires 
  close 
  observation 
  at 
  times 
  to 
  make 
  certain 
  whether 
  apterous- 
  

   specimens 
  are 
  nymphs 
  or 
  adults. 
  The 
  full 
  development 
  of 
  the 
  geni- 
  

   talia 
  and 
  the 
  three, 
  instead 
  of 
  two, 
  segmented 
  tarsi, 
  however, 
  serve 
  

   to 
  identify 
  adults 
  in 
  such 
  cases. 
  

  

  KEY 
  TO 
  THE 
  SPECIES. 
  

  

  1. 
  Fore 
  trochanters 
  with 
  one 
  or 
  more 
  spines 
  (sometimes 
  merely 
  bristles), 
  usu- 
  

  

  ally 
  set 
  on 
  raised 
  bases 
  (the 
  body 
  of 
  trochanter 
  itself 
  often 
  acutely 
  pro- 
  

   duced 
  ) 
  , 
  never 
  with 
  numerous 
  setae 
  ; 
  fore 
  femur 
  with 
  4 
  to 
  7 
  stout 
  spines 
  

   which 
  are 
  always 
  set 
  on 
  more 
  or 
  less 
  distinctly 
  enlarged 
  and 
  elevated 
  

   bases, 
  standing 
  in 
  line 
  with 
  or 
  almost 
  in 
  line 
  with 
  a 
  larger 
  number 
  of 
  much 
  

   smaller 
  spines 
  or 
  bristles 
  on 
  the 
  posteroventral 
  surface, 
  the 
  longer 
  spines 
  

   sometimes 
  with 
  an 
  outward 
  curvature 
  (fig. 
  80) 
  ; 
  apical 
  antennal 
  segment 
  

   longer 
  than 
  subapical, 
  never 
  shorter 
  than 
  it; 
  length 
  of 
  fore 
  coxa 
  variable 
  

  

  in 
  relation 
  to 
  length 
  of 
  fore 
  tibia 
  (Subgenus 
  Ploiaria) 
  2 
  

  

  Fore 
  trochanters 
  nearly 
  bare 
  or 
  with 
  few 
  to 
  numerous 
  fine 
  hairs, 
  one 
  or 
  two 
  

   of 
  which 
  are 
  sometimes 
  bristle-like 
  ; 
  fore 
  femur 
  with 
  the 
  spines 
  or 
  bristles 
  

   on 
  the 
  posteroventral 
  surface 
  more 
  uniform 
  in 
  length, 
  the 
  larger 
  bristles 
  

   lacking 
  enlarged 
  elevated 
  bases, 
  and 
  almost 
  straight 
  (fig. 
  74) 
  ; 
  apical 
  

   antennal 
  segment 
  shorter 
  than 
  subapical, 
  equal 
  to 
  it 
  only 
  in 
  setulifera; 
  

   fore 
  coxa 
  invariably 
  longer 
  than 
  fore 
  tibia 
  (Subgenus 
  Luteva) 
  16 
  

  

  2. 
  Posterior 
  lobe 
  of 
  head 
  with 
  a 
  prominent 
  median 
  backwardly 
  projecting 
  spine 
  

  

  (fig. 
  S5) 
  3 
  

  

  Posterior 
  lobe 
  of 
  head 
  lacking 
  spine 
  4 
  

  

  3 
  Last 
  tergite 
  of 
  male 
  with 
  a 
  slender, 
  obtuse, 
  strap-shaped 
  process 
  extending 
  

   back 
  over 
  hypopygium 
  and 
  closely 
  adherent 
  to 
  it 
  (fig. 
  86) 
  ; 
  hind 
  margin 
  of 
  

   hypopygium 
  as 
  in 
  figure 
  87; 
  median 
  process 
  of 
  seventh 
  tergite 
  of 
  female 
  

   extending 
  distinctly 
  farther 
  caudad 
  than 
  the 
  acute 
  lateral 
  angles 
  (fig. 
  88). 
  

  

  denticauda, 
  new 
  species 
  (p. 
  63), 
  

   Last 
  tergite 
  of 
  male 
  with 
  a 
  shorter, 
  pointed 
  process 
  (fig. 
  92) 
  ; 
  hind 
  margin 
  

   of 
  hypopygium 
  as 
  in 
  figure 
  91 
  ; 
  median 
  process 
  of 
  seventh 
  tergite 
  of 
  fe- 
  

   male 
  extending 
  but 
  little 
  farther 
  caudad 
  than 
  the 
  rounded 
  lateral 
  angles 
  

   (fig. 
  90) 
  hirticornis 
  (Banks) 
  (p. 
  04). 
  

  

  4. 
  Posterior 
  lobe 
  of 
  head 
  with 
  an 
  erect 
  spinelet 
  at 
  margin 
  of 
  eye 
  on 
  each 
  side 
  

  

  behind 
  constriction 
  reticulata 
  (Baker) 
  (p. 
  63). 
  

  

  Posterior 
  lobe 
  of 
  head 
  not 
  so 
  armed 
  5 
  

  

  5. 
  Posterior 
  lobe 
  of 
  head 
  with 
  a 
  more 
  or 
  less 
  prominent 
  median 
  ridge 
  6 
  

  

  Posterior 
  lobe 
  of 
  head 
  lacking 
  such 
  a 
  ridge 
  7 
  

  

  6. 
  Posterior 
  lobe 
  of 
  head 
  with 
  a 
  slight 
  central 
  elevation 
  anteriorly, 
  and 
  an- 
  

  

  other 
  posteriorly, 
  between 
  which 
  there 
  is 
  a 
  low 
  longitudinal 
  ridge; 
  ante- 
  

   rior 
  lobe 
  of 
  head 
  sulcate 
  behind 
  ; 
  fore 
  coxa 
  little 
  longer 
  than 
  fore 
  tibia 
  ; 
  

   a 
  highly 
  colored 
  species, 
  beak 
  with 
  two 
  dark 
  bands, 
  mid 
  and 
  hind 
  femora 
  

   fuscous 
  apically, 
  each 
  with 
  a 
  subapical 
  pale 
  annulus, 
  the 
  corresponding 
  

   tibiae 
  fuscous 
  basally, 
  with 
  subbasal 
  pale 
  annuli. 
  

  

  granulata, 
  new 
  species 
  (p. 
  57). 
  

   Posterior 
  lobe 
  of 
  head 
  with 
  a 
  more 
  or 
  less 
  distinct 
  median 
  carina. 
  (This 
  

   is 
  true 
  of 
  uniseriata 
  and 
  punctipes 
  which 
  run 
  on 
  other 
  characters 
  be- 
  

   ginning 
  with 
  next 
  couplet 
  7 
  

  

  