﻿504 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  DOROCORDULiA 
  gen. 
  nov. 
  

  

  Cordulia 
  libera 
  Selys, 
  type 
  

  

  The 
  three 
  species 
  here 
  separated 
  from 
  Somatochlora 
  and 
  placed 
  

   in 
  this 
  new 
  genus 
  differ 
  from 
  Somatochlora 
  by 
  a 
  number 
  of 
  

   important 
  venational 
  and 
  other 
  characters, 
  among 
  which 
  are 
  the 
  following 
  r 
  

  

  1 
  The 
  triangle 
  of 
  the 
  fore 
  wing 
  is 
  open 
  : 
  it 
  is 
  traversed 
  by 
  a 
  cross 
  vein 
  in 
  

  

  Somatochlora. 
  

  

  2 
  There 
  are 
  never 
  more 
  than 
  two 
  complete 
  rows 
  of 
  cells 
  beyond 
  the 
  triangle 
  in 
  

  

  the 
  fore 
  wings 
  : 
  there 
  are 
  more 
  than 
  two 
  in 
  Somatochlora. 
  

  

  3 
  The 
  second 
  cubito-anal 
  cross 
  vein 
  (and, 
  therefore, 
  an 
  internal 
  triangle 
  or 
  sub- 
  

  

  triangle) 
  is 
  wanting 
  in 
  the 
  hind 
  wing 
  ; 
  it 
  is 
  present 
  in 
  Somatochlora. 
  

  

  4 
  There 
  is 
  a 
  long 
  space 
  beyond 
  the 
  single 
  cross 
  vein 
  nnder 
  the 
  stigma: 
  in 
  

  

  Somatochlora 
  the 
  spaces 
  are 
  more 
  nearly 
  equal, 
  and 
  there 
  are 
  often 
  

   two 
  cross 
  veins 
  under 
  the 
  stigma. 
  

  

  The 
  Cordulia 
  lintneri 
  of 
  Hagen 
  may 
  not 
  belong 
  here 
  : 
  in 
  

   fact 
  it 
  may 
  belong 
  in 
  the 
  subfamily 
  Libellulinae. 
  I 
  leave 
  it 
  here 
  beside 
  

   the 
  species 
  with 
  which 
  it 
  has 
  been 
  associated 
  pending 
  farther 
  study, 
  and 
  

   awaiting 
  the 
  discovery 
  of 
  its 
  nymph. 
  It 
  will 
  be 
  found 
  not 
  to 
  agree 
  with 
  

   characters 
  2 
  and 
  4 
  of 
  the 
  above 
  statement. 
  

  

  This 
  genus 
  is 
  more 
  closely 
  allied 
  to 
  Cordulia 
  than 
  to 
  Somat- 
  

   ochlora, 
  but 
  it 
  differs 
  from 
  Cordulia 
  by 
  characters 
  i 
  and 
  2 
  as 
  

   stated 
  above, 
  as 
  well 
  as 
  by 
  the 
  lack 
  of 
  the 
  deep 
  bifurcation 
  of 
  the 
  inferior 
  

   appendage 
  of 
  the 
  male 
  which 
  is 
  characteristic 
  of 
  Cordulia. 
  The 
  

   nymph 
  also, 
  I 
  found 
  much 
  more 
  easy 
  to 
  distinguish 
  from 
  that 
  of 
  

   Somatochlora 
  elongata 
  than 
  from 
  that 
  of 
  Cordulia 
  shurt- 
  

   1 
  e 
  f 
  f 
  i. 
  The 
  nymph 
  is 
  known 
  for 
  the 
  single 
  species 
  D. 
  libera. 
  

  

  Our 
  imagos 
  are 
  readily 
  separable 
  into 
  species 
  by 
  the 
  following 
  key 
  : 
  

  

  a 
  Abdomen 
  with 
  segments 
  7 
  to 
  10 
  spatulately 
  dilated 
  libera 
  

  

  aa 
  Abdomen 
  gradually 
  and 
  very 
  moderately 
  widened 
  at 
  apex 
  

  

  & 
  The 
  articulations 
  of 
  the 
  abdominal 
  segments 
  yellow 
  le 
  pida 
  

  

  && 
  The 
  articulations 
  of 
  the 
  abdominal 
  segments 
  not 
  yellow 
  lintneri 
  

  

  Dorocordulia 
  libera 
  Selys 
  

  

  1871 
  Cordulia 
  libera 
  Selys, 
  Acad. 
  Belg. 
  (2) 
  Bui. 
  21:262 
  

   1895 
  Somatochlora 
  libera 
  Calvert, 
  N. 
  Y. 
  ent. 
  soc. 
  Jour. 
  3 
  : 
  46 
  (listed 
  

   from 
  the 
  CatsMU 
  mountains) 
  

  

  This 
  dainty 
  and 
  beautiful 
  corduline 
  species 
  was 
  not 
  uncommon 
  at 
  

   Saranac 
  Inn. 
  But 
  few 
  specimens 
  were 
  taken, 
  because 
  no 
  special 
  effort 
  

   was 
  made 
  to 
  get 
  them. 
  The 
  imagos 
  obtained 
  were 
  taken 
  when 
  flying, 
  

   with 
  Cordulia 
  shurtleffi 
  about 
  the 
  borders 
  of 
  the 
  bog 
  ponds 
  

   mentioned 
  under 
  the 
  account 
  of 
  that 
  species. 
  They 
  are 
  less 
  swift 
  of 
  

  

  