﻿AQUATIC 
  INSECTS 
  IN 
  THE 
  ADIRONDACKS 
  S^S 
  

  

  The 
  nymph, 
  Uke 
  that 
  of 
  the 
  preceding 
  and 
  that 
  of 
  the 
  following 
  

   species 
  (the 
  only 
  differences 
  that 
  I 
  have 
  observed 
  between 
  these 
  I 
  have 
  

   already 
  stated 
  in 
  a 
  footnote 
  to 
  the 
  nymph 
  table) 
  has 
  nine 
  lateral 
  setae, 
  

   and 
  12 
  mentals, 
  of 
  which 
  the 
  fifth 
  (counting 
  from 
  the 
  side) 
  is 
  longest; 
  

   the 
  dorsal 
  hooks 
  on 
  segments 
  4-8 
  are 
  low, 
  less 
  considerable 
  in 
  length 
  

   than 
  the 
  segments 
  which 
  bear 
  them, 
  but 
  sharp 
  ; 
  the 
  lateral 
  spines 
  of 
  the 
  

   eighth 
  and 
  ninth 
  segments 
  are 
  less 
  developed, 
  and 
  follow 
  in 
  their 
  external 
  

   contour 
  the 
  incurvate 
  lines 
  of 
  the 
  posteriorly 
  narrowing 
  abdomen 
  ; 
  the 
  

   lateral 
  appendages 
  are 
  half 
  as 
  long 
  as 
  the 
  inferiors, 
  which 
  are 
  distinctly 
  

   longer 
  then 
  the 
  superior. 
  

  

  Sympetrum 
  obtrusum 
  Hagen 
  

  

  Figure 
  30 
  

  

  1867 
  Diplax 
  obtrusa 
  Hagen, 
  Stett. 
  ent. 
  zeit. 
  28 
  : 
  95 
  

  

  1893 
  Diplax 
  obtrusa 
  Calvert, 
  Am. 
  ent. 
  soc. 
  Trans. 
  20:264 
  (description 
  and 
  

   figure) 
  

  

  1899 
  Diplax 
  obtrusa 
  Kellicotfc, 
  Odon. 
  Ohio, 
  p. 
  109 
  (description 
  and 
  figure) 
  

  

  1900 
  Diplax 
  obtrusa 
  Williamson, 
  Dragon 
  flies 
  Ind. 
  p. 
  323 
  (description) 
  

  

  For 
  this 
  and 
  the 
  two 
  foregoing 
  species 
  I 
  have 
  hardly 
  thought 
  it 
  worth 
  

   while 
  to 
  state 
  the 
  distribution 
  in 
  detail, 
  it 
  is 
  so 
  general 
  throughout 
  the 
  

   state, 
  whenever 
  any 
  collecting 
  has 
  been 
  done. 
  

  

  Sympetrum 
  albifrons 
  Charpentier 
  

  

  Figure 
  30 
  

  

  1841 
  Libellula 
  albifrons 
  Charpentier, 
  Lib. 
  Europ. 
  p. 
  81, 
  pi. 
  11, 
  fig. 
  3 
  

   1861 
  Diplax 
  albifrons 
  Hagen, 
  Synopsis 
  Neur. 
  N. 
  Am. 
  p. 
  177 
  

   1900 
  Sympetrum 
  albifrons 
  Williamson, 
  Dragon 
  flies 
  Ind. 
  p. 
  323 
  (descrip- 
  

   tion) 
  

  

  Not 
  yet 
  found 
  in 
  the 
  state 
  ; 
  nymph 
  unknown. 
  

  

  Sympetrum 
  corruptum 
  Hagen 
  

  

  1861 
  Mesothemis 
  oorrupta 
  Hagen, 
  Synopsis 
  Neur. 
  N. 
  Am. 
  p. 
  171 
  

  

  1893 
  Diplax 
  corrupta 
  Calvert, 
  Am. 
  ent. 
  soc. 
  Trans. 
  20:264 
  (description) 
  

  

  1897 
  Diplax 
  corrupta 
  Calvert, 
  N. 
  Y. 
  ent. 
  soc. 
  Jour. 
  5:95 
  (listed 
  from 
  

  

  Staten 
  Island) 
  

   1897 
  Diplax 
  corrupta 
  Van 
  Duzee, 
  N. 
  Y. 
  ent. 
  soc. 
  Jour. 
  5:91 
  (listed 
  from 
  

  

  Lake 
  Erie) 
  

  

  1899 
  Diplax 
  corrupta 
  Kellicott, 
  Odon. 
  Ohio, 
  p. 
  Ill 
  (description) 
  

  

  1900 
  Diplax 
  corrupta 
  Williamson, 
  Dragon 
  flies 
  lad. 
  p. 
  324 
  (description) 
  

  

  This 
  species 
  is 
  inuch 
  niore 
  common 
  westward 
  ; 
  its 
  nymph 
  is 
  unknown, 
  

  

  