﻿NO. 
  1953. 
  REVISION 
  OF 
  FAMILY 
  PTYCHOPTERIDJE— 
  ALEXANDER. 
  333 
  

  

  gate, 
  slender, 
  extremely 
  pointed 
  stylets 
  which 
  I 
  believe 
  to 
  be 
  

   homologous 
  with 
  the 
  maxillae 
  of 
  certain 
  other 
  Diptera 
  (Tabanidae); 
  

   at 
  the 
  base 
  of 
  the 
  maxillae, 
  beneath 
  the 
  cl}^eus, 
  arise 
  the 
  elongated 
  

   maxillary 
  palpi 
  (c), 
  which 
  are 
  almost 
  as 
  long 
  as 
  the 
  antennae; 
  these 
  

   palpi 
  are 
  5-segmented; 
  segment 
  1 
  short; 
  2 
  twice 
  as 
  long 
  as 
  1; 
  3 
  

   longer 
  than 
  1 
  and 
  2 
  combined; 
  4 
  and 
  5 
  subequal, 
  longer 
  than 
  2 
  

   but 
  shorter 
  than 
  3 
  ; 
  palpi 
  clothed 
  mth 
  long 
  appressed 
  hairs 
  ; 
  between 
  

   the 
  labrum 
  and 
  labium, 
  there 
  projects 
  an 
  elongated 
  stylet, 
  almost 
  

   as 
  broad 
  as 
  the 
  labrum, 
  which 
  seems 
  to 
  be 
  homologous 
  with 
  the 
  

   hypopharynx 
  (/); 
  the 
  possibiUty 
  exists, 
  however, 
  that 
  it 
  may 
  con- 
  

   sist 
  of 
  the 
  two 
  mandibles 
  closely 
  applied 
  to 
  one 
  another. 
  The 
  

   specimen 
  is 
  unique 
  and 
  I 
  do 
  not 
  care 
  to 
  

   remove 
  the 
  mouth 
  parts. 
  The 
  elon- 
  

   gated 
  labium 
  Qi) 
  apparently 
  2-seg- 
  

   mented, 
  and 
  bearing 
  a 
  pair 
  of 
  broad 
  

   palpi 
  at 
  the 
  tip, 
  arises 
  from 
  the 
  ven- 
  

   tral 
  surface 
  of 
  the 
  head; 
  viewed 
  from 
  

   beneath, 
  the 
  labium 
  is 
  seen 
  to 
  consist 
  

   of 
  a 
  basal 
  and 
  apical 
  piece, 
  the 
  latter 
  

   deeply 
  di^dded 
  by 
  a 
  longitudinal 
  fur- 
  

   row 
  ; 
  the 
  palpi 
  divergent, 
  tjieir 
  margins 
  

   clothed 
  with 
  long, 
  stout 
  hairs; 
  from 
  

   between 
  the 
  palpi 
  there 
  projects 
  out- 
  

   ward 
  a 
  narrow 
  compressed 
  organ 
  {g) 
  ; 
  

   this 
  may 
  (in 
  case 
  the 
  organ 
  (/) 
  de- 
  

   scribed 
  above 
  as 
  possibly 
  being 
  the 
  

   hypopharynx 
  is 
  not 
  this) 
  be 
  the 
  hypo- 
  

   pharynx. 
  In 
  this 
  case 
  the 
  mandibles 
  

   would 
  be 
  present 
  and 
  accounted 
  for 
  in 
  

   the 
  organ 
  described 
  above 
  as 
  the 
  hypo- 
  

   pharynx. 
  

  

  Occipital 
  region 
  narrowed 
  behind, 
  

   broadening 
  to 
  the 
  vertex; 
  vertex 
  nar- 
  

   rowed 
  between 
  the 
  eyes, 
  its 
  sides 
  j^arallel; 
  front 
  encroaching 
  onto 
  the 
  

   inner 
  margui 
  of 
  the 
  eye 
  m 
  a 
  broad, 
  shallow 
  sinus, 
  in 
  which 
  the 
  anten- 
  

   nae 
  (a) 
  are 
  located. 
  Antennae, 
  17-segmented; 
  the 
  scapal 
  segments 
  

   almost 
  smooth 
  or 
  with 
  very 
  small 
  hairs; 
  both 
  segments 
  short, 
  the 
  

   first 
  cylindrical, 
  the 
  second 
  oval, 
  its 
  distal 
  end 
  more 
  enlarged; 
  the 
  

   flagellar 
  segments 
  clothed 
  with 
  dense 
  appressed 
  hairs; 
  basal 
  flageUar 
  

   segments 
  almost 
  subequal; 
  apical 
  segments 
  more 
  elongated. 
  (See 
  

   figs. 
  1 
  and 
  2.) 
  

  

  Mouth-parts 
  yellow, 
  the 
  labium 
  brown; 
  maxillary 
  palpi 
  dark 
  

   brown; 
  clypeus 
  dull 
  brownish 
  gray; 
  antennae 
  dark 
  brown, 
  the 
  cloth- 
  

   ing 
  of 
  hairs 
  on 
  the 
  flagellum 
  rather 
  paler. 
  

  

  Fig. 
  2.— 
  Dorsal 
  aspect 
  of 
  the 
  head 
  of 
  

   Tanyderus 
  patagonicus. 
  o, 
  Antenna; 
  

   6, 
  clypeus; 
  c, 
  maxillary 
  palpus; 
  d, 
  

   labrum; 
  e, 
  maxilla. 
  

  

  