﻿462 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  bodies 
  of 
  water. 
  Prof. 
  Herrick 
  of 
  the 
  Agricultural 
  college 
  of 
  Mississippi 
  

   found 
  it 
  transforming 
  abundantly 
  on 
  the 
  shore 
  of 
  Canandaigua 
  lake 
  at 
  

   the 
  natural 
  science 
  camp 
  in 
  June 
  1897. 
  I 
  have 
  found 
  it 
  at 
  Ithaca 
  and 
  

   at 
  Saranac 
  Inn; 
  at 
  the 
  latter 
  place 
  only 
  in 
  Little 
  Clear 
  pond, 
  near 
  the 
  

   outlet. 
  That 
  was 
  during 
  the 
  week 
  which 
  included 
  June 
  30. 
  The 
  

   nymphs 
  were 
  crawHng 
  up 
  out 
  of 
  rather 
  deep 
  water 
  on 
  stumps 
  and 
  logs 
  

   on 
  the 
  bank 
  to 
  transform. 
  

  

  A 
  big 
  pine 
  stump 
  that 
  stood 
  partly 
  in 
  the 
  water, 
  halfway 
  between 
  the 
  

   outlet 
  and 
  the 
  cold 
  water 
  pipe, 
  seemed 
  a 
  favorite 
  place 
  of 
  transformation. 
  

   It 
  was 
  fajrly 
  dotted 
  over 
  with 
  exuviae, 
  most 
  of 
  which 
  were 
  several 
  feet 
  

   above 
  the 
  water. 
  No 
  imagos 
  were 
  seen, 
  excepting 
  the 
  few 
  that 
  were 
  

   bred. 
  

  

  Nymph. 
  (PI. 
  18, 
  fig. 
  i) 
  Total 
  length 
  33 
  mm; 
  abdomen 
  22 
  mm 
  

   hind 
  femur 
  7 
  mm; 
  width 
  of 
  head 
  6 
  mm, 
  of 
  abdomen 
  7 
  mm. 
  

  

  Body 
  elongate, 
  httle 
  depressed, 
  little 
  hairy; 
  color 
  dirty 
  brownish^ 
  

   becoming 
  clear 
  brown 
  on 
  the 
  apex 
  of 
  the 
  abdomen 
  ; 
  some 
  darker 
  mark- 
  

   ings 
  on 
  the 
  sides 
  of 
  the 
  thorax 
  and 
  at 
  the 
  lateral 
  margins 
  of 
  the 
  abdo- 
  

   men, 
  and 
  across 
  the 
  base 
  of 
  the 
  dorsum 
  of 
  the 
  middle 
  abdominal 
  

   segments. 
  

  

  Head 
  cordate 
  in 
  outline, 
  the 
  hind 
  margin 
  being 
  broadly 
  emarginate 
  ; 
  

   antennae 
  long, 
  considerably 
  surpassing 
  the 
  tip 
  of 
  the 
  labrum, 
  and 
  

   upturned 
  beyond 
  the 
  end 
  of 
  it; 
  first 
  segment 
  twice 
  as 
  large 
  as 
  the 
  second^ 
  

   both 
  globular 
  ; 
  third 
  segment 
  narrowly 
  cylindric, 
  more 
  than 
  twice 
  as 
  long 
  

   as 
  the 
  two 
  basal 
  ones 
  together, 
  bearing 
  the 
  minute, 
  rudimentary, 
  

   globular, 
  fourth 
  segment 
  on 
  its 
  upturned 
  lip 
  ; 
  burrowing 
  hooks 
  well 
  

   developed. 
  

  

  Abdomen 
  narrowed 
  beyond 
  the 
  sixth 
  segment 
  rather 
  regularly; 
  dorsal 
  

   hook 
  on 
  segments 
  2-9 
  regularly 
  increasing 
  in 
  size 
  and 
  sharpness, 
  and 
  

   regularly 
  increasingly 
  declined 
  posteriorly, 
  that 
  on 
  segment 
  9 
  being 
  a 
  

   direct 
  continuation 
  of 
  the 
  sharp 
  middorsal 
  ridge 
  of 
  the 
  segment, 
  black 
  

   tipped, 
  lateral 
  spines 
  on 
  segments 
  6-9 
  increasing 
  in 
  size 
  posteriorly, 
  those 
  

   of 
  the 
  ninth 
  segment 
  reaching 
  the 
  level 
  of 
  the 
  middle 
  of 
  the 
  loth 
  seg- 
  

   ment; 
  the 
  eighth 
  segment 
  is 
  a 
  third 
  longer 
  than 
  the 
  loth; 
  the 
  ninth 
  

   segment 
  is 
  two 
  and 
  one 
  half 
  times 
  as 
  long 
  as 
  the 
  loth; 
  the 
  superior 
  and 
  

   inferior 
  appendages 
  are 
  somewhat 
  longer 
  than 
  the 
  loth 
  segment, 
  but 
  the 
  

   laterals 
  are 
  about 
  equal 
  to 
  it, 
  being 
  about 
  one 
  fourth 
  shorter 
  than 
  the 
  

   other 
  appendages. 
  

  

  The 
  mentum 
  of 
  the 
  labium 
  is 
  rather 
  regularly 
  widened 
  anteriorly, 
  with 
  

   a 
  straight 
  front 
  border; 
  lateral 
  lobes 
  strongly 
  arcuate, 
  with 
  end 
  hook, 
  

   distinctly 
  more 
  prominent 
  than 
  the 
  nine 
  or 
  ten 
  coarse, 
  angulately 
  serrate 
  

   teeth 
  before 
  it 
  on 
  the 
  inner 
  margin. 
  

  

  Subfamily 
  aeschninae: 
  

   This 
  group 
  includes 
  the 
  largest, 
  fleetest, 
  and 
  most 
  voracious 
  of 
  our 
  

   dragon 
  flies. 
  Many 
  of 
  them 
  are 
  common 
  and 
  very 
  well 
  known. 
  Most 
  

   of 
  the 
  species 
  are 
  marked 
  with 
  bright 
  blues 
  and 
  greens. 
  They 
  roam 
  far 
  

   from 
  water, 
  and 
  often 
  find 
  their 
  way 
  into 
  houses 
  in 
  warm 
  weather. 
  Several, 
  

   species 
  are 
  commonly 
  seen 
  coursing 
  over 
  lawns 
  in 
  the 
  evening 
  twilight. 
  

  

  