﻿AQUATIC 
  INSECTS 
  IN 
  THE 
  ADIRONDACKS 
  493 
  

  

  SPECIES 
  OF 
  TETRAGONEURIA 
  

  

  Imagos 
  

  

  <i 
  Frons 
  with 
  a 
  black 
  T-spot 
  abov^e; 
  triangle 
  of 
  hind 
  wings 
  generally 
  without 
  

  

  a 
  cross 
  vein 
  spinigera 
  

  

  <ia 
  Frons 
  without 
  a 
  T-spot 
  above; 
  triangle 
  of 
  hind 
  wings 
  generally 
  traversed 
  by 
  

  

  a 
  cross 
  vein 
  

  

  h 
  Superior 
  appendage 
  of 
  the 
  male 
  not 
  declined 
  at 
  tip, 
  and 
  without 
  superior 
  

  

  ante-apical 
  spine. 
  Hind 
  wings 
  generally 
  with 
  four 
  antenodal 
  cross 
  veins. 
  

  

  c 
  Hind 
  wing 
  with 
  isolated 
  basal 
  streaks 
  which 
  hardly 
  surpass 
  the 
  level 
  of 
  

  

  the 
  first 
  antenodal 
  cross 
  vein 
  cynosura 
  

  

  €0 
  Hind 
  wings 
  with 
  broader, 
  and 
  more 
  confluent 
  markings, 
  reaching 
  the 
  

  

  level 
  of 
  the 
  third 
  or 
  fourth 
  antenodal 
  cross 
  vein 
  semiaquea 
  

  

  2>& 
  The 
  superior 
  appendage 
  of 
  the 
  male 
  strongly 
  declined 
  at 
  the 
  tip 
  beyond 
  a 
  

   superior 
  ante-apical 
  spine 
  ; 
  hind 
  wings 
  generally 
  with 
  five 
  antenodal 
  cross 
  

   veins, 
  some 
  of 
  the 
  anteuodals 
  surrounded 
  by 
  fuscous 
  spots. 
  .. 
  s 
  p 
  i 
  n 
  o 
  s 
  a 
  

  

  Nymphs 
  

  

  a 
  Spines 
  of 
  the 
  ninth 
  abdominal 
  segment 
  strongly 
  divergent, 
  their 
  tips 
  dis- 
  

   tinctly 
  wider 
  apart 
  than 
  their 
  bases 
  on 
  the 
  outer 
  sides 
  spinigera 
  

  

  <a,a 
  Lateral 
  spines 
  of 
  the 
  ninth 
  segment, 
  very 
  slightly 
  or 
  not 
  at 
  all 
  divergent 
  

   & 
  Spines 
  of 
  the 
  ninth 
  abdominal 
  segment 
  longer 
  than.the 
  segment 
  

   c 
  Spines 
  of 
  the 
  ninth 
  segment 
  hardly 
  longer 
  than 
  is 
  the 
  segment 
  on 
  its 
  

  

  dorsal 
  side 
  (fig. 
  20) 
  cynosura 
  

  

  cc 
  Spines 
  of 
  the 
  ninth 
  segment 
  one 
  third 
  to 
  one 
  half 
  longer 
  than 
  is 
  the 
  

  

  segment 
  on 
  its 
  ventral 
  side 
  semiaquea 
  

  

  hh 
  Spines 
  of 
  the 
  ninth 
  segment 
  distinctly 
  shorter 
  than 
  that 
  segment, 
  and 
  

   slightly 
  incurved 
  at 
  tips 
  spinosa, 
  supposition 
  

  

  Tetragoneuria 
  spinigera 
  Selys 
  

  

  1871 
  Tetragon 
  euri 
  a 
  spinigera 
  Selys, 
  Acad. 
  Belg. 
  (2) 
  Bui. 
  31:269 
  

   1897 
  Tetragoneuria 
  spinigera 
  Van 
  Duzee, 
  N. 
  Y. 
  ent. 
  soc. 
  Jour. 
  5:90 
  

  

  (listed 
  from 
  Buffalo) 
  

   1897 
  Tetragon 
  euri 
  a 
  spinigera 
  Calvert, 
  N. 
  Y. 
  ent. 
  soc. 
  Jour. 
  5:95 
  

  

  (listed 
  from 
  Buffalo) 
  

   1900 
  Tetragone 
  u 
  ria 
  spinigera 
  Williamson, 
  Dragon 
  flies 
  Ind. 
  p. 
  311 
  

  

  (description) 
  

   To 
  the 
  above 
  record 
  by 
  Van 
  Duzee 
  of 
  this 
  species 
  from 
  Buffalo 
  

   (repeated 
  by 
  Calvert 
  in 
  his 
  list), 
  I 
  have 
  to 
  add 
  two 
  localities. 
  It 
  was 
  

   exceedingly 
  abundant 
  at 
  Saranac 
  Inn 
  during 
  the 
  month 
  of 
  June, 
  flying 
  

   about 
  the 
  grounds 
  of 
  the 
  hatchery 
  in 
  company 
  with 
  the 
  other 
  two 
  species 
  

   occurring 
  there 
  — 
  flying, 
  also, 
  about 
  every 
  other 
  little 
  clearing 
  in 
  the 
  

   forest, 
  foraging. 
  It 
  was 
  very 
  common 
  toward 
  the 
  mouth 
  of 
  Buttermilk 
  

   creek 
  near 
  Ithaca 
  in 
  June 
  1897. 
  

  

  