﻿4^6 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  NEUROCORDULIA 
  

  

  No 
  species 
  of 
  this 
  genus 
  has 
  been 
  taken 
  within 
  the 
  limits 
  of 
  this 
  state, 
  

   but 
  the 
  following 
  one 
  is 
  regional, 
  being 
  distributed 
  from 
  Massachusetts 
  to 
  

   Indiana. 
  The 
  nymph 
  of 
  the 
  genus 
  is 
  unknown, 
  unless 
  the 
  one 
  described 
  

   below 
  be 
  it. 
  That 
  nymph 
  described 
  and 
  figured 
  by 
  Cabot 
  and 
  indicated 
  

   as 
  belonging 
  possibly 
  to 
  this 
  species, 
  is 
  Libellula 
  pulchella. 
  

  

  Neurocordulia 
  obsoleta 
  Say 
  

  

  1839 
  Libellula 
  obsoleta 
  Say, 
  Acad. 
  nat. 
  sci. 
  Phil. 
  Jour. 
  8: 
  28 
  

  

  1839 
  Libellula 
  polysticta 
  Bnrraeister, 
  Handb. 
  ent. 
  2 
  : 
  856 
  

  

  1861 
  D 
  i 
  dym 
  op 
  s 
  obsoleta 
  Hagen, 
  Synopsis 
  Neur. 
  N. 
  Am. 
  p. 
  136 
  

  

  1873 
  Epitheca 
  "obsoleta 
  Hagen, 
  Bost. 
  soc. 
  nat. 
  hist. 
  Proc. 
  15 
  : 
  269 
  

  

  1863 
  Cordulia 
  modesta 
  Walsh, 
  Ent. 
  soc. 
  Phil 
  . 
  Proc, 
  2 
  : 
  254 
  

  

  1890 
  Epitheca 
  obsoleta 
  Hagen, 
  Psyche, 
  5 
  : 
  369, 
  pi. 
  1, 
  fig. 
  7-9 
  (critical 
  

  

  notes, 
  with 
  figures 
  of 
  the 
  accessory 
  genitalia) 
  

   1893 
  Neurocordulia 
  obsoleta 
  Calvert, 
  Am. 
  ent. 
  soc. 
  Trans. 
  20:252 
  

  

  (description) 
  

   1900 
  Neurocordulia 
  obsoleta 
  Williamson, 
  Dragon 
  flies 
  Ind. 
  p. 
  312 
  

  

  This 
  species 
  seems 
  to 
  be 
  everywhere 
  rare. 
  I 
  have 
  not 
  seen 
  it 
  at 
  

   large. 
  There 
  are 
  very 
  few 
  specimens 
  in 
  collections. 
  It 
  is 
  very 
  different 
  

   in 
  many 
  particulars 
  from 
  all 
  the 
  other 
  Cordulinae, 
  It 
  ' 
  is 
  very 
  desirable 
  

   that 
  some 
  one 
  should 
  rear 
  it. 
  The 
  imago 
  will 
  be 
  easily 
  recognized 
  by 
  

   the 
  characters 
  given 
  in 
  the 
  table. 
  I 
  describe 
  below 
  a 
  nymph 
  from 
  Penn- 
  

   sylvania 
  which 
  probably 
  belongs 
  here. 
  

  

  Nymph. 
  (Not 
  grown) 
  Measures 
  in 
  total 
  length 
  i8 
  mm; 
  abdomen 
  

   Smm; 
  hind 
  femur 
  5 
  mm; 
  width 
  of 
  head 
  5 
  mm, 
  of 
  abdomen 
  8 
  mm; 
  

   length 
  of 
  body 
  without 
  antennae 
  17 
  mm. 
  

  

  A 
  singularly 
  fiat-bodied, 
  short-legged 
  nymph 
  with 
  exceptionally 
  con- 
  

   tracted 
  abdomen, 
  smooth, 
  blackish 
  in 
  color, 
  with 
  traces 
  of 
  paler 
  bands 
  on 
  

   the 
  femora 
  and 
  tibiae. 
  

  

  Head 
  dorsally 
  flattened, 
  with 
  a 
  pair 
  of 
  low, 
  submedian, 
  vertical 
  

   tubercles, 
  and 
  a 
  shelf-like, 
  scurfy 
  pubescent 
  frontal 
  ridge, 
  as 
  long 
  as 
  the 
  

   two 
  basal 
  segments 
  of 
  the 
  antennae 
  ; 
  antennae 
  seven 
  jointed 
  ; 
  joint 
  i 
  

   cylindric, 
  2, 
  globular, 
  these 
  of 
  equal 
  length 
  ; 
  segments 
  3-7 
  slightly 
  decreas- 
  

   ing 
  in 
  length 
  to 
  the 
  conic 
  seventh 
  segment. 
  Hind 
  angles 
  of 
  the 
  head 
  

   obtuse, 
  but 
  prominent 
  posteriorly, 
  overhanging 
  the 
  front 
  of 
  the 
  protho- 
  

   rax 
  ; 
  hind 
  margin 
  of 
  the 
  head 
  excavate 
  between 
  the 
  hind 
  angles. 
  

  

  Labium 
  short 
  and 
  broad, 
  hardly 
  extending 
  posteriorly 
  beyond 
  the 
  

   bases 
  of 
  the 
  fore 
  legs; 
  mentum 
  broadly 
  triangular, 
  contracted 
  at 
  its 
  base, 
  

   concave 
  within, 
  its 
  sharp 
  superolateral 
  margins 
  spinous 
  at 
  both 
  ends; 
  

   median 
  lobe 
  moderately 
  prominent, 
  with 
  a 
  few 
  minute 
  spinules 
  on 
  the 
  

   front 
  border 
  of 
  it, 
  declined 
  ; 
  mental 
  setae 
  eight 
  or 
  nine, 
  the 
  three 
  or 
  four 
  

   innermost 
  ones 
  quite 
  small 
  each 
  side; 
  lateral 
  lobes 
  triangular, 
  concave 
  

   within, 
  its 
  distal 
  border 
  cut 
  in 
  about 
  seven 
  semi-elliptic 
  teeth, 
  each 
  armed 
  

   at 
  its 
  tip 
  with 
  two 
  or 
  three 
  spinules, 
  lateral 
  setae 
  five; 
  movable 
  hook 
  a 
  

   little 
  longer 
  and 
  stronger 
  than 
  the 
  setae, 
  gently 
  arcuate. 
  

  

  There 
  is 
  a 
  distinct 
  occipital 
  ridge 
  on 
  the 
  rear 
  of 
  the 
  head 
  below 
  the 
  

   level 
  of 
  the 
  vertex, 
  closely 
  appHed 
  to 
  a 
  corresponding 
  ridge 
  on 
  the 
  front 
  

  

  