﻿AQUATIC 
  INSECTS 
  IN 
  THE 
  ADIRONDACKS 
  48/ 
  

  

  margin 
  of 
  the 
  prothorax. 
  The 
  dorsal 
  shield 
  of 
  the 
  prothorax 
  farther 
  

   l30unded 
  on 
  the 
  posterior 
  side 
  by 
  a 
  transverse 
  ridge, 
  which 
  curves 
  forward 
  

   at 
  its 
  ends 
  to 
  terminate 
  in 
  a 
  pair 
  of 
  prominent 
  lateral 
  processes 
  ; 
  there 
  is 
  

   also 
  an 
  obtuse 
  supra-coxal 
  process 
  each 
  side 
  which 
  extends 
  forward 
  close 
  

   beside 
  the 
  head 
  halfway 
  from 
  the 
  hind 
  angles 
  of 
  the 
  head 
  to 
  the 
  eyes. 
  

  

  Body 
  depressed 
  ; 
  legs 
  smooth, 
  wide 
  apart, 
  the 
  three 
  pairs 
  successively- 
  

   more 
  remote 
  from 
  each 
  other 
  at 
  base, 
  the 
  middle 
  and 
  hind 
  femora 
  each 
  

   with 
  a 
  superior 
  ridge, 
  the 
  fore 
  and 
  middle 
  tibiae 
  each 
  with 
  a 
  ridge, 
  start- 
  

   ing 
  at 
  its 
  base 
  exteriorly 
  (dorsally) 
  and 
  at 
  once 
  curving 
  to 
  extend 
  down 
  

   its 
  anterior 
  face; 
  tarsi 
  three-jointed, 
  the 
  third 
  joint 
  about 
  as 
  long 
  as 
  the 
  

   two 
  basal 
  together, 
  the 
  claw 
  short 
  and 
  stout, 
  about 
  as 
  long 
  as 
  the 
  basal 
  

   joint. 
  

  

  Abdomen 
  flat, 
  suborbicular, 
  granulate, 
  with 
  a 
  row 
  of 
  oval 
  smooth 
  scars 
  

   midway 
  between 
  the 
  median 
  line 
  and 
  the 
  lateral 
  margin 
  each 
  side 
  on 
  

   segments 
  4-8; 
  wing 
  cases 
  reaching 
  but 
  to 
  the 
  middle 
  of 
  the 
  fourth 
  

   abdommal 
  segment 
  (the 
  nymph 
  is 
  apparently 
  not 
  grown); 
  there 
  is 
  a 
  row 
  

   of 
  conspicuous 
  dorsal 
  hooks 
  starting 
  from 
  between 
  the 
  wing 
  cases 
  and 
  end- 
  

   ing 
  on 
  segment 
  9 
  ; 
  strongly 
  flattened 
  laterally, 
  not 
  hooked 
  at 
  all, 
  but 
  erect, 
  

   and 
  rounded 
  on 
  tips, 
  highest 
  on 
  the 
  sixth 
  segment; 
  ventral 
  sutures 
  wide 
  

   apart, 
  shghtly 
  convergent 
  posteriorly, 
  disappearing 
  on 
  the 
  ninth 
  segment; 
  

   basal 
  abdominal 
  segments 
  extremely 
  contracted, 
  segment 
  i 
  telescoped 
  by 
  

   the 
  metathorax, 
  visible 
  only 
  in 
  the 
  middle 
  of 
  the 
  ventral 
  side 
  ; 
  genitalia 
  

   ( 
  $ 
  ) 
  visible 
  at 
  the 
  midventral 
  apex 
  of 
  segment 
  2; 
  lateral 
  spines 
  on 
  8 
  and 
  

   9, 
  long 
  and 
  sharp, 
  divergent 
  on 
  8, 
  parallel 
  on 
  9 
  and 
  as 
  long 
  as 
  the 
  

   segment, 
  greatly 
  surpassing 
  the 
  appendages 
  ; 
  segment 
  9 
  excavate 
  above 
  

   between 
  the 
  lateral 
  spines, 
  to 
  inclose 
  the 
  annular 
  loth 
  segment 
  and 
  the 
  

   appendages, 
  one 
  half 
  as 
  long 
  on 
  the 
  middorsal 
  as 
  on 
  the 
  midventral 
  line 
  ; 
  

   inferior 
  appendages 
  about 
  as 
  long 
  as 
  segment 
  9 
  is 
  on 
  the 
  dorsal 
  side, 
  the 
  

   superior 
  and 
  the 
  laterals 
  successively 
  shorter, 
  the 
  latter 
  a 
  little 
  longer 
  

   than 
  half 
  the 
  inferiors 
  ; 
  segment 
  10 
  about 
  half 
  the 
  dorsal 
  length 
  of 
  the 
  

   ninth 
  segment 
  ; 
  inferior 
  apical 
  and 
  lateral 
  margins 
  of 
  the 
  ninth 
  segment 
  

   fringed 
  with 
  long 
  hairs. 
  

  

  A 
  single 
  nymph 
  1, 
  sent 
  me 
  by 
  Dr 
  Calvert, 
  from 
  the 
  collection 
  of 
  the 
  

   Academy 
  of 
  natural 
  sciences 
  of 
  Philadelphia, 
  bearing 
  the 
  label, 
  

   *'H. 
  C. 
  Borden, 
  Pa. 
  Oct. 
  26, 
  '95 
  ". 
  

  

  The 
  flat 
  abdomen 
  with 
  erect 
  blunt 
  dorsal 
  hooks 
  and 
  smooth 
  lateral 
  scars, 
  

   and 
  the 
  elongate 
  third 
  tarsal 
  segment 
  recall 
  Hagenius, 
  while 
  the 
  

   broad 
  mask- 
  shaped 
  labium, 
  the 
  vertical 
  tubercles 
  and 
  the 
  frontal 
  ridge 
  

   recall 
  Epicordulia. 
  The 
  transverse 
  occipital 
  ridge, 
  the 
  curving 
  

   carina 
  on 
  the 
  fore 
  and 
  middle 
  tibiae, 
  and 
  the 
  extreme 
  abbreviation 
  of 
  the 
  

   basal 
  abdominal 
  segments 
  are 
  characters 
  which 
  I 
  do 
  not 
  recall 
  having 
  

   observed 
  in 
  any 
  other 
  nymphs 
  whatever. 
  

  

  1 
  Since 
  the 
  above 
  was 
  written 
  I 
  have 
  received 
  exuviae 
  from 
  Dr 
  Calvert, 
  taken 
  at 
  White 
  lake 
  in 
  

   the 
  Catskills, 
  and 
  from 
  E. 
  B. 
  Williamson, 
  taken 
  at 
  Nashville 
  Tenn., 
  of 
  this 
  same 
  species. 
  The 
  

   ■length 
  of 
  the 
  nymyh 
  when 
  grown 
  is 
  21 
  mm. 
  I 
  now 
  feel 
  quite 
  certain 
  that 
  these 
  belong 
  to 
  Neu- 
  

   rocordulia. 
  

  

  