﻿AQUATIC 
  INSECTS 
  IN 
  THE 
  ADIRONDACKS 
  435 
  

  

  flowing 
  or 
  clear 
  water; 
  abundantly 
  represented 
  throughout 
  New 
  York 
  

   state. 
  The 
  nymphs 
  are 
  burrowers 
  in 
  the 
  beds 
  of 
  streams 
  and 
  ponds. 
  

   The 
  females 
  oviposit 
  unattended 
  by 
  the 
  males, 
  and 
  liberate 
  their 
  eggs 
  in 
  

   the 
  water 
  during 
  flight 
  by 
  descending 
  repeatedly 
  and 
  striking 
  the 
  surface 
  

   of 
  the 
  water 
  with 
  the 
  tip 
  of 
  the 
  abdomen. 
  The 
  eggs 
  have 
  a 
  scanty 
  

   envelop 
  of 
  gelatin 
  ; 
  they 
  tend 
  apart 
  in 
  falling, 
  to 
  he 
  scattered 
  on 
  the 
  

   bottom, 
  where 
  they 
  are 
  at 
  once 
  hidden 
  by 
  the 
  silt 
  which 
  adheres 
  to 
  the 
  

   gelatin. 
  The 
  following 
  key 
  will 
  serve 
  for 
  the 
  separation 
  of 
  the 
  genera 
  

   likely 
  to 
  be 
  found 
  within 
  our 
  limits. 
  

  

  KEY 
  TO 
  GENERA 
  

  

  Imagos 
  

   -a 
  Basal 
  subcostal 
  cross 
  vein 
  (see 
  fig. 
  9) 
  present 
  ; 
  a 
  linear 
  or 
  spatalate, 
  

   median, 
  sternal 
  process 
  on 
  the 
  first 
  abdominal 
  segment; 
  legs 
  very 
  short, 
  

   the 
  hind 
  femora 
  hardly 
  reaching 
  the 
  apex 
  of 
  the 
  first 
  abdominal 
  seg- 
  

   ment 
  Progomphus 
  

  

  4ia 
  No 
  basal 
  subcostal 
  cross 
  vein 
  ; 
  no 
  median 
  sternal 
  process 
  on 
  the 
  first 
  

   abdominal 
  segment 
  ; 
  legs 
  longer, 
  the 
  hind 
  femora 
  reaching 
  or 
  surpassing 
  

   the 
  middle 
  of 
  the 
  second 
  abdominal 
  segment 
  

   & 
  Hind 
  wings 
  with 
  a 
  distinct 
  anal 
  loop 
  (see 
  fig. 
  18 
  a) 
  consisting 
  of 
  several 
  

   cells 
  

   c 
  Anal 
  loop 
  normally 
  consisting 
  of 
  three 
  cells 
  ; 
  first 
  and 
  fifth 
  antenodal 
  cross 
  

   veins 
  matched 
  in 
  position 
  and 
  hypertrophied 
  ; 
  stigma 
  broad 
  with 
  both 
  

   sides 
  convex; 
  triangles 
  not 
  traversed 
  by 
  cross 
  vein 
  s.O 
  phi 
  ogomphus 
  

   CQ 
  Anal 
  loop 
  consisting 
  normally 
  of 
  four 
  cells 
  ; 
  first 
  and 
  seventh 
  antenodel 
  

   cross 
  veins 
  matched 
  in 
  position 
  and 
  hypertrophied; 
  stigma 
  long 
  and 
  

   narrow 
  with 
  parallel 
  sides; 
  each 
  triangle 
  divided 
  by 
  a 
  cross 
  vein 
  

  

  Hagenius 
  p. 
  440 
  

  

  €>6 
  Hind 
  wings 
  with 
  no 
  distinct 
  anal 
  loop, 
  or 
  with 
  one 
  consisting 
  of 
  a 
  single 
  cell 
  

  

  c 
  Triangle 
  of 
  the 
  fore 
  wing 
  one 
  third 
  shorter 
  than 
  that 
  of 
  the 
  hind 
  wing 
  ; 
  

  

  generally 
  a 
  single 
  cell 
  between 
  the 
  bases 
  of 
  veins 
  A2 
  and 
  A3 
  ..Lanthus 
  

  

  cc 
  Triangle 
  of 
  the 
  fore 
  wing 
  less 
  tlian 
  one 
  fourth 
  shorter 
  than 
  that 
  of 
  the 
  

  

  hind 
  wing 
  ; 
  generally, 
  two 
  or 
  more 
  cells 
  between 
  A3 
  and 
  A3 
  at 
  their 
  origin 
  

  

  d! 
  Hind 
  femora 
  naked, 
  or 
  with 
  numerous 
  short 
  spines 
  

  

  Gomphus, 
  seris.lat. 
  p. 
  443 
  

   dd 
  Hind 
  femora 
  with 
  five 
  to 
  seven 
  long, 
  strong 
  spines 
  

  

  Dromogomphusp. 
  461 
  

  

  n 
  Middle 
  legs 
  more 
  approximate 
  at 
  the 
  base 
  than 
  are 
  the 
  fore 
  legs; 
  fourth 
  seg- 
  

   ment 
  of 
  the 
  antenna 
  slender, 
  erect, 
  about 
  as 
  long 
  as 
  the 
  third 
  segment 
  is 
  

   wide 
  ; 
  10th 
  abdominal 
  segment 
  about 
  as 
  long 
  as 
  the 
  ninth 
  

  

  Progomphus 
  

  

  4ia 
  Middle 
  legs 
  not 
  more 
  (usually 
  less) 
  approkimate 
  than 
  the 
  fore 
  legs 
  at 
  base 
  ; 
  

  

  the 
  fourth 
  segment 
  of 
  the 
  antenna 
  a 
  mere 
  rudiment, 
  orbicular 
  or 
  discoid, 
  

  

  much 
  shorter 
  than 
  the 
  third 
  segment 
  is 
  wide; 
  10th 
  abdominal 
  segment 
  

  

  much 
  shorter 
  than 
  the 
  ninth 
  

  

  