﻿AQUATIC 
  INSECTS 
  IN 
  THE 
  ADIRONDACKS 
  481 
  

  

  Imagos 
  

  

  '<a 
  Dorsal 
  surface 
  oftlie 
  head 
  with 
  the 
  occipat 
  larger 
  than 
  the 
  vertex; 
  sub- 
  

   triangle 
  of 
  the 
  fore 
  wings 
  usually 
  divided 
  by 
  a 
  cross 
  vein 
  ; 
  four 
  to 
  six 
  cross 
  

   veins 
  in 
  the 
  space 
  above 
  the 
  bridge 
  {see 
  fig. 
  9) 
  Didymops 
  

  

  ua 
  Dorsal 
  surface 
  of 
  the 
  head 
  with 
  the 
  occiput 
  much 
  smaller 
  than 
  the 
  vertex 
  ; 
  

   subtriaugle 
  of 
  the 
  fore 
  wings 
  generally 
  open; 
  two 
  or 
  three 
  cross 
  veins 
  in 
  

   the 
  space 
  above 
  the 
  bridge 
  Macromia 
  

  

  Nymphs 
  

  

  a 
  Head 
  hardly 
  as 
  wide 
  across 
  the 
  eyes 
  as 
  across 
  the 
  bulging 
  hind 
  angles 
  ; 
  

   lateral 
  spines 
  not 
  incurved, 
  those 
  of 
  the 
  ninth 
  abdominal 
  segment 
  hardly 
  

   surpassed 
  by 
  the 
  tips 
  of 
  the 
  appendages 
  ; 
  dorsum 
  of 
  the 
  lOth^abdominal 
  seg- 
  

   ment 
  with 
  no 
  trace 
  of 
  a 
  dorsal 
  hook 
  Didymops 
  

  

  <ia 
  Head 
  widest 
  across 
  the 
  eyes 
  ; 
  spines 
  of 
  the 
  ninth 
  abdominal 
  segment 
  shorter, 
  

   not 
  nearly 
  reaching 
  the 
  level 
  of 
  the 
  apices 
  of 
  the 
  appendages 
  ; 
  dorsum 
  of 
  

   the 
  10th 
  segment 
  with 
  a 
  very 
  rudimentary 
  dorsal 
  hook 
  .Macromia 
  

  

  DIDYMOPS 
  

  

  There 
  is 
  a 
  single 
  species. 
  

  

  Didymops 
  transversa 
  Say 
  

  

  1839 
  Libellula 
  transversa 
  Say, 
  Acad. 
  nat. 
  sei. 
  Phil. 
  Jour. 
  8:19 
  

   1861 
  Didymops 
  transversa 
  Hagen, 
  Synopsis 
  Neur. 
  N. 
  Am. 
  p. 
  135 
  

   1875 
  Macromia 
  transversa 
  Hagen, 
  Bost. 
  soc. 
  nat. 
  hist. 
  Proc. 
  18 
  : 
  57 
  

  

  (full 
  bibliography, 
  and 
  distribution) 
  

   1890 
  Macromia 
  transversa 
  Cabot, 
  Immature 
  state 
  Odon. 
  pt 
  3, 
  p. 
  14-16, 
  

   pi. 
  1, 
  fig. 
  3 
  (full 
  bibliography, 
  description 
  of 
  nymph 
  and 
  distribution) 
  

   1893 
  Didymops 
  transversa 
  Calvert, 
  Am. 
  ent. 
  soc. 
  Trans. 
  20:250 
  (de- 
  

   scription) 
  

  

  1899 
  Didymops 
  transversa 
  Kellicott, 
  Odon. 
  Ohio, 
  p. 
  88 
  (description) 
  

  

  1900 
  Didymops 
  transversa 
  Williamson, 
  Dragon 
  flies 
  Ind. 
  p. 
  307 
  (de- 
  

  

  scription) 
  

  

  This 
  is 
  a 
  common 
  species 
  in 
  woodland 
  streams 
  and 
  ponds, 
  in 
  water 
  

   of 
  a 
  little 
  depth, 
  in 
  shaded 
  pools, 
  etc., 
  where 
  there 
  is 
  litde 
  vegetation. 
  

   It 
  was 
  not 
  very 
  common 
  at 
  Saranac 
  Inn, 
  but 
  nymphs 
  were 
  taken 
  in 
  the 
  

   borders 
  of 
  Little 
  Clear 
  pond 
  and 
  creek, 
  and 
  exuviae 
  were 
  found 
  along 
  the 
  

   eastern 
  shore 
  of 
  Lake 
  Clear, 
  hung 
  up 
  in 
  the 
  bushes, 
  or 
  attached 
  to 
  large 
  

   rocks 
  several 
  yards 
  from 
  the 
  water's 
  edge. 
  Imagos 
  were 
  observed 
  only 
  

   about 
  the 
  borders 
  of 
  the 
  larger 
  bodies 
  of 
  water. 
  They 
  could 
  always 
  be 
  

   seen 
  darting 
  in 
  and 
  out 
  of 
  the 
  edges 
  of 
  the 
  woods 
  on 
  the 
  fragrant 
  shores 
  

   of 
  Little 
  Green 
  pond. 
  

  

  Nymph. 
  (PI. 
  i8, 
  fig. 
  8) 
  Measures 
  in 
  total 
  length, 
  ^27 
  mm, 
  $ 
  29 
  

   mm; 
  abdomen 
  19mm; 
  hind 
  femur 
  11 
  mm; 
  width 
  of 
  head 
  7 
  mm, 
  of 
  

   abdomen 
  13 
  mm. 
  Body 
  flat, 
  thin 
  edged, 
  with 
  legs 
  wide 
  apart 
  at 
  bases 
  

   and 
  sprawling. 
  Color 
  yellowish 
  below, 
  mottled 
  brownish 
  above, 
  the 
  

  

  