﻿408 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Plate 
  15 
  shows 
  the 
  forms 
  which 
  I 
  found 
  together 
  in 
  this 
  little 
  rapids 
  by 
  

   the 
  railroad. 
  Simulium 
  is 
  vastly 
  more 
  numerous 
  in 
  individuals 
  than 
  all 
  

   the 
  other 
  species 
  put 
  together 
  and 
  also 
  more 
  restricted 
  in 
  its 
  habitat. 
  

   The 
  next 
  in 
  numerical 
  importance 
  would 
  probably 
  be 
  the 
  pygmy 
  May 
  

   fly, 
  Baetis 
  pygmaea 
  Hagen, 
  though 
  a 
  larger 
  May 
  fly, 
  H 
  e 
  p 
  t 
  a 
  - 
  

   genia 
  pulchella 
  Walsh, 
  and 
  a 
  caddis 
  fly, 
  Hydropsyche 
  sp.? 
  

   (see 
  p. 
  566 
  ) 
  seemed 
  almost 
  as 
  numerous. 
  These 
  three 
  species 
  are 
  

   probably 
  predatory, 
  feeding 
  on 
  the 
  members 
  of 
  the 
  Simulium 
  colony. 
  

   The 
  other 
  members 
  of 
  this 
  httle 
  society 
  are 
  much 
  fewer. 
  They 
  are 
  i 
  ) 
  a 
  

   hitherto 
  unknown 
  fly 
  of 
  the 
  family 
  Empididae, 
  Roederiodes 
  juncta 
  

   Coq., 
  (described 
  post 
  at 
  p. 
  586 
  ) 
  whose 
  larvae 
  crawl 
  about 
  among 
  the 
  

   Simulium 
  pupa 
  cases, 
  and 
  pupate 
  within 
  empty 
  cases, 
  and 
  2) 
  the 
  stone 
  

   fly, 
  Leuctra 
  tenella. 
  

  

  It 
  must 
  be 
  another, 
  earlier 
  species 
  of 
  black 
  fly 
  which 
  makes 
  all 
  the 
  

   trouble 
  in 
  the 
  Adirondacks 
  with 
  its 
  bites 
  ; 
  for 
  this 
  one 
  is 
  quite 
  peaceably 
  

   disposed. 
  Guides 
  have 
  a 
  saying, 
  that, 
  when 
  the 
  black 
  flies 
  put 
  on 
  their 
  

   white 
  stockings 
  in 
  June, 
  the 
  trouble 
  is 
  about 
  over. 
  This 
  species 
  has 
  the 
  

   " 
  white 
  stockings." 
  

  

  I 
  was 
  interested 
  in 
  watching 
  the 
  females 
  of 
  this 
  species 
  ovipositing, 
  and 
  

   saw 
  the 
  operation 
  very 
  frequently. 
  The 
  place 
  selected 
  is 
  always 
  at 
  the 
  

   edge 
  of 
  a 
  little 
  waterfafl, 
  on 
  a 
  surface 
  that 
  is 
  intermittently 
  washed 
  by 
  the 
  

   swaying 
  current, 
  and 
  so 
  kept 
  wet 
  [seepl. 
  15). 
  Here 
  the 
  females 
  flock, 
  

   and 
  pile 
  up 
  great 
  white 
  masses 
  of 
  eggs, 
  which 
  with 
  a 
  little 
  age 
  turn 
  

   yellowish. 
  Waves 
  dash 
  over 
  them 
  while 
  ovipositing, 
  and 
  often 
  sweep 
  

   them 
  away, 
  but 
  they 
  at 
  once 
  return 
  to 
  their 
  task. 
  

  

  I 
  do 
  not 
  know 
  what 
  Simulium 
  larvae 
  feed 
  on 
  ; 
  but 
  their 
  tentacles 
  seem 
  

   well 
  adapted 
  for 
  straining 
  plankton 
  from 
  the 
  water 
  that 
  dashes 
  over 
  them. 
  

  

  The 
  life 
  of 
  the 
  hatchery 
  pipes 
  and 
  troughs. 
  The 
  Hfe 
  of 
  the 
  

  

  pipes 
  is 
  essentially 
  that 
  of 
  the 
  rapids.^ 
  What 
  is 
  living 
  in 
  the 
  pipes 
  is 
  

   learned 
  by 
  observing 
  what 
  comes 
  out 
  of 
  them, 
  into 
  the 
  hatchery 
  troughs 
  

   and 
  into 
  the 
  windows. 
  Simulium, 
  Hydropsyche, 
  Hepta- 
  

   genia 
  and 
  Baetis, 
  were 
  in 
  the 
  hatchery 
  windows 
  throughout 
  the 
  

   session, 
  often 
  in 
  enormous 
  numbers. 
  Their 
  periods 
  of 
  greatest 
  abund- 
  

   ance 
  do 
  not 
  coincide 
  however. 
  The 
  windows 
  were 
  fairly 
  darkened 
  with 
  

   black 
  flies 
  and 
  caddis 
  flies 
  and 
  the 
  larger 
  May 
  flies, 
  Heptagenia, 
  

   during 
  the 
  earlier 
  part 
  of 
  the 
  session, 
  while 
  the 
  pygmy 
  May 
  flies 
  did 
  not 
  

   appear 
  in 
  swarming 
  numbers 
  tiU 
  the 
  latter 
  part 
  of 
  it. 
  The 
  only 
  member 
  

   of 
  the 
  Simulium 
  society 
  as 
  portrayed 
  in 
  the 
  plate, 
  which 
  was 
  not 
  observed 
  

  

  1 
  It 
  appears 
  that 
  the 
  niollusks 
  which 
  get 
  into 
  city 
  water 
  pipes 
  and 
  sometimes 
  cause 
  trouble 
  are 
  

   forms 
  that 
  normally 
  live 
  in 
  rapids. 
  

  

  