﻿438 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  ing, 
  the 
  females 
  seemed 
  to 
  remain 
  less 
  of 
  the 
  time 
  in 
  the 
  vicinity 
  of 
  the 
  

   water. 
  The 
  female 
  makes 
  a 
  succession 
  of 
  sweeps 
  back 
  and 
  forth 
  near 
  

   the 
  head 
  of 
  some 
  little 
  riffle, 
  striking 
  the 
  water, 
  after 
  short 
  flights, 
  again 
  

   and 
  again 
  near 
  the 
  same 
  place, 
  leaving 
  her 
  eggs 
  in 
  it. 
  

  

  Imagos, 
  living 
  and 
  mature, 
  are 
  of 
  a 
  rich, 
  deep 
  green 
  color 
  with 
  the 
  

   usual 
  oblique 
  stripes 
  of 
  blackish 
  brown. 
  Unfortunately, 
  the 
  color 
  fades 
  

   readily, 
  even 
  where 
  daylight 
  is 
  excluded. 
  The 
  few 
  imagos 
  which 
  I 
  took 
  

   the 
  time 
  to 
  gather 
  were 
  nearly 
  all 
  netted 
  while 
  resting 
  on 
  a 
  water 
  pipe 
  

   which 
  crosses 
  a 
  riffle 
  just 
  below 
  the 
  railroad 
  bridge. 
  

  

  The 
  nymphs 
  were 
  very 
  common 
  in 
  the 
  sandy 
  bed 
  of 
  the 
  creek. 
  A 
  

   great 
  many 
  were 
  raked 
  up 
  and 
  sifted 
  out 
  with 
  a 
  sieve 
  net 
  while 
  collecting 
  

   for 
  other 
  material. 
  The 
  cast 
  skins 
  were 
  abundant 
  along 
  the 
  banks 
  

   through 
  the 
  months 
  of 
  June 
  and 
  July, 
  sticking 
  to 
  whatever 
  support 
  

   offered, 
  within 
  a 
  foot 
  of 
  the 
  edge 
  of 
  the 
  water. 
  

  

  Nymph, 
  (pi. 
  i8, 
  fig. 
  5) 
  Total 
  length 
  27.5 
  mm; 
  abdomen 
  17.5 
  mm 
  ; 
  

   hind 
  femur 
  5 
  mm; 
  width 
  of 
  head 
  5 
  mm, 
  of 
  abdomen 
  7.5 
  mm. 
  

  

  Legs, 
  genae, 
  sides 
  of 
  the 
  antennae, 
  and 
  lateral 
  margins 
  of 
  the 
  abdomen, 
  

   hairy 
  ; 
  the 
  general 
  dorsum 
  nearly 
  bare 
  ; 
  well 
  developed 
  burrowing 
  hooks 
  

   at 
  the 
  apices 
  of 
  the 
  fore 
  and 
  middle 
  tibiae. 
  

  

  Abdomen 
  oval 
  in 
  outline 
  as 
  seen 
  from 
  above, 
  abruptly 
  narrowed 
  on 
  

   the 
  ninth 
  segment; 
  the 
  loth 
  segment 
  one 
  third 
  shorter 
  than 
  the 
  ninth; 
  

   the 
  lateral 
  abdominal 
  appendages 
  two 
  thirds 
  as 
  long 
  as 
  the 
  others; 
  very 
  

   short, 
  subequal 
  lateral 
  spines 
  on 
  the 
  seventh 
  to 
  the 
  ninth 
  segments 
  ; 
  

   dorsal 
  hooks 
  represented 
  on 
  the 
  second 
  to 
  ninth 
  segments 
  by 
  blunt 
  rudi- 
  

   ments, 
  which 
  are 
  erect 
  on 
  the 
  front 
  and 
  posteriorly 
  directed 
  on 
  the 
  hind 
  

   segments, 
  each 
  surmounting 
  a 
  low 
  transverse 
  ridge, 
  which 
  extends 
  across 
  

   the 
  dorsum 
  and 
  disappears 
  down 
  on 
  the 
  sides 
  on 
  each 
  segment. 
  Anterior 
  

   two 
  thirds 
  of 
  each 
  segment, 
  including 
  this 
  ridge, 
  prickly 
  granulate; 
  

   posterior 
  third 
  polished, 
  shining, 
  smooth. 
  

  

  Mentum 
  of 
  labium 
  one 
  third 
  longer 
  than 
  wide, 
  dilated 
  beyond 
  its 
  

   basal 
  third 
  and 
  upturned 
  so 
  as 
  to 
  be 
  flaring 
  upward 
  at 
  its 
  edges 
  ; 
  median 
  

   lobe 
  distinctly 
  rounded 
  and 
  fringed 
  with 
  flat 
  scales, 
  and 
  bordered 
  be- 
  

   sides 
  with 
  a 
  row 
  of 
  low, 
  broad, 
  rectangular 
  teeth; 
  lateral 
  lobe 
  incurved, 
  

   rounded 
  on 
  the 
  apex 
  and 
  not 
  bearing 
  a 
  terminal 
  hook 
  or 
  sharp 
  angle, 
  its 
  

   internal 
  margin 
  bordered 
  with 
  a 
  row 
  of 
  12 
  to 
  15 
  low 
  teeth. 
  

  

  Color 
  greenish 
  or 
  brownish, 
  with 
  paler 
  and 
  darker 
  mottlings; 
  apical 
  

   pale 
  rings 
  on 
  all 
  femora; 
  a 
  pair 
  of 
  transversely 
  elongate 
  whitish 
  spots 
  on 
  

   the 
  dorsum 
  of 
  the 
  seventh 
  abdominal 
  segment, 
  repeated 
  on 
  the 
  eighth 
  seg- 
  

   ment, 
  but 
  there 
  divided 
  into 
  two 
  spots 
  each 
  side; 
  a 
  whitish 
  spot 
  each 
  

   side 
  of 
  the 
  loth 
  segment 
  beside 
  the 
  base 
  of 
  the 
  superior 
  appendage; 
  tips 
  

   of 
  all 
  the 
  abdominal 
  appendages 
  whitish. 
  

  

  The 
  nymph 
  is 
  a 
  rapid 
  burrower, 
  trailing 
  along 
  at 
  slight 
  depth 
  through 
  

   nearly 
  clean 
  sand 
  under 
  the 
  currents, 
  often 
  leaving 
  a 
  faint 
  line 
  behind 
  

   showing 
  where 
  the 
  tip 
  of 
  the 
  abdomen, 
  upturned 
  for 
  respiration, 
  has 
  

   pushed 
  the 
  sand 
  grains 
  aside. 
  

  

  