﻿424 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  1863 
  Baetis 
  alternatus 
  Walsb, 
  Ent. 
  soc. 
  Phil. 
  Proc. 
  2 
  : 
  189 
  

   1853 
  Baetis 
  annulata 
  Walker, 
  List 
  Neur. 
  ins. 
  Brit. 
  mus. 
  3 
  : 
  567 
  

   1861 
  Baetis 
  annulata 
  Hagen, 
  Synopsis 
  Neur. 
  N. 
  Am. 
  p. 
  48 
  

  

  1876 
  Baetis 
  femorata 
  Provancher, 
  Nat. 
  Canadienne. 
  8 
  : 
  267 
  

  

  1877 
  Baetis 
  femorata 
  Provancher, 
  Faun. 
  ent. 
  du 
  Canada. 
  2 
  : 
  83 
  

  

  1871 
  Siphlurus 
  annulatus 
  Eaton, 
  Ent. 
  soc. 
  Lond. 
  Trans, 
  p. 
  127 
  (de- 
  

   scription 
  in 
  Latin: 
  figures 
  of 
  forceps 
  of 
  male, 
  and 
  ventral 
  abdomiual 
  

   markings 
  in 
  pi. 
  6, 
  fig. 
  4 
  and 
  4a) 
  

   1871 
  S 
  iphl 
  urns 
  al 
  t 
  e 
  rnatu 
  s 
  Eaton, 
  Ent. 
  soe. 
  Lond. 
  Trans, 
  p. 
  129 
  

   1877 
  Siphlurus 
  alternatus 
  Provancher, 
  Faun. 
  ent. 
  du 
  Canada. 
  2 
  : 
  83 
  

   1885 
  Siphlurus 
  alternatus 
  Eaton, 
  Linn. 
  soc. 
  Lond. 
  Trans. 
  (2) 
  3:219^ 
  

   1892 
  Siphlurus 
  alternatus 
  Banks, 
  Am. 
  ent. 
  soc. 
  Trans. 
  19 
  : 
  346 
  (listed) 
  

  

  This 
  handsome 
  brown 
  species 
  was 
  not 
  observed 
  at 
  large, 
  was 
  not 
  

   taken 
  in 
  our 
  trap 
  lanterns, 
  and 
  was 
  only 
  obtained 
  by 
  rearing 
  nymphs. 
  

   These 
  were 
  not 
  uncommon 
  in 
  shallow 
  water 
  about 
  the 
  outlet 
  of 
  Little 
  

   Clear 
  pond 
  among 
  the 
  debris 
  of 
  fallen 
  brushwood. 
  Doubtless 
  the 
  imagos 
  

   might 
  have 
  been 
  found 
  at 
  large, 
  had 
  careful 
  search 
  been 
  made 
  of 
  the 
  

   shores 
  about 
  these 
  same 
  places. 
  

  

  The 
  nymph 
  is 
  a 
  graceful 
  .creature, 
  and 
  exceedingly 
  agile. 
  The 
  

   beautiful 
  fringes 
  on 
  the 
  abdominal 
  setae 
  constitute 
  a 
  powerful 
  tail 
  fin, 
  

   one 
  stroke 
  of 
  which 
  sends 
  the 
  nymph 
  through 
  the 
  water 
  with 
  a 
  speed 
  

   the 
  eye 
  can 
  hardly 
  follow. 
  It 
  is 
  exceedingly 
  difficult 
  to 
  pick 
  up 
  one 
  

   of 
  the 
  nymphs, 
  when 
  confined 
  in 
  a 
  little 
  dish 
  of 
  water, 
  with 
  a 
  forceps, 
  sO' 
  

   quickly 
  will 
  they 
  dart 
  away. 
  In 
  a 
  water 
  net 
  of 
  some 
  size 
  they 
  are 
  easily 
  

   taken, 
  however, 
  apparently 
  not 
  finding 
  themselves 
  ensnared 
  till 
  lifted 
  

   from 
  the 
  water. 
  A 
  good 
  many 
  specimens 
  were 
  taken 
  in 
  shallow 
  water 
  

   behind 
  a 
  large 
  hummock 
  overgrown 
  with 
  cattails 
  ( 
  T 
  y 
  p 
  h 
  a 
  ) 
  to 
  the 
  

   north 
  of 
  the 
  outlet 
  of 
  Little 
  Clear 
  pond. 
  These 
  transformed 
  July 
  21, 
  

   22 
  and 
  23, 
  and 
  remained 
  in 
  the 
  subimago 
  stage 
  for 
  more 
  than 
  48 
  hours, 
  

   in 
  every 
  case, 
  undergoing 
  the 
  final 
  molt 
  during 
  the 
  second 
  day 
  after 
  

   emergence 
  from 
  the 
  larval 
  skin. 
  

  

  This 
  species 
  is 
  widely 
  distributed 
  throughout 
  the 
  eastern 
  United 
  States. 
  

  

  Nymph. 
  PI. 
  n, 
  fig. 
  5, 
  6 
  Length 
  of 
  body 
  15 
  mm; 
  setae 
  6.5 
  mm 
  

   additional; 
  abdomen 
  9.5 
  mm; 
  antennae 
  i 
  mm. 
  

  

  Body 
  arched, 
  tapering, 
  very 
  graceful 
  and 
  exceedingly 
  well 
  adapted 
  for 
  

   swimming. 
  Abdomen 
  somewhat 
  depressed 
  and 
  upcurved 
  at 
  the 
  tip. 
  

   Face 
  vertically 
  elongated, 
  with 
  an 
  aspect 
  singularly 
  like 
  that 
  of 
  the 
  face 
  

   of 
  the 
  common 
  grasshopper. 
  

  

  Head 
  and 
  prothorax 
  short, 
  each 
  about 
  twice 
  as 
  wide 
  as 
  long; 
  meso- 
  

   thorax 
  large 
  and 
  prominent; 
  abdomen 
  a 
  little 
  wider 
  in 
  the 
  middle, 
  

   tapering 
  slightly 
  to 
  the 
  end, 
  serrated 
  on 
  each 
  side 
  by 
  the 
  prolongation 
  

   of 
  the 
  posterolateral 
  angles 
  of 
  segments 
  1-9 
  in 
  sharp, 
  single, 
  back- 
  

   wardly 
  directed 
  teeth, 
  which 
  become 
  largest 
  on 
  the 
  sides 
  of 
  the 
  8th 
  

   segment, 
  and 
  sharpest 
  and 
  thinnest 
  on 
  the 
  sides 
  of 
  the 
  ninth: 
  loth 
  

   segment 
  cylindric, 
  two 
  thirds 
  as 
  wide 
  as 
  the 
  ninth. 
  

  

  