﻿AQUATIC 
  INSECTS 
  IN 
  THE 
  ADIRONDACKS 
  527 
  

  

  Nymph. 
  Total 
  length 
  21 
  mm 
  ; 
  abdomen 
  12 
  mm 
  ; 
  hind 
  femur 
  6 
  mm 
  ; 
  

   width 
  of 
  head 
  6 
  mm, 
  of 
  abdomen 
  7.5 
  mm. 
  

  

  Easily 
  recognizable 
  among 
  other 
  libelluline 
  nymphs 
  (when 
  well 
  grown 
  

   at 
  least) 
  by 
  the 
  head 
  twice 
  as 
  wide 
  as 
  long, 
  the 
  entire 
  absence 
  of 
  dorsal 
  

   hooks, 
  the 
  smooth 
  and 
  depressed 
  body, 
  and 
  by 
  the 
  superior 
  appendage 
  

   being 
  one 
  third 
  shorter 
  than 
  the 
  inferiors 
  and 
  twice 
  as 
  long 
  as 
  the 
  

   laterals. 
  The 
  labium 
  is 
  large, 
  and 
  the 
  median 
  lobe 
  is 
  at 
  its 
  maximum 
  

   size; 
  hook 
  long 
  and 
  slender; 
  laterals 
  10; 
  mentals 
  about 
  12, 
  the 
  fifth 
  or 
  

   sixth 
  (counting 
  from 
  the 
  side) 
  longest; 
  the 
  lateral 
  spines 
  of 
  the 
  eighth 
  

   and 
  ninth 
  segments 
  of 
  the 
  abdomen 
  are 
  very 
  similar 
  in 
  size 
  and 
  shape, 
  

   those 
  of 
  the 
  ninth 
  segment 
  extending 
  posteriorly 
  almost 
  to 
  the 
  level 
  of 
  

   the 
  tips 
  of 
  the 
  inferior 
  appendages. 
  

  

  MESOTHEMIS 
  

  

  There 
  is 
  a 
  single 
  species 
  occurring 
  within 
  the 
  state. 
  

   Mesothemis 
  simplicicollis 
  Say 
  

  

  1839 
  Libel 
  1 
  ula 
  simplicicollis 
  Say, 
  Acad. 
  nat. 
  sci. 
  Phil. 
  Jour. 
  8:28 
  

   1861 
  Me 
  sot 
  h 
  em 
  is 
  simplicicollis 
  Hagen, 
  Synopsis 
  Neur. 
  N. 
  Am. 
  p, 
  170 
  

   1893 
  Meso 
  themis 
  simplicicollis 
  Calvert, 
  Am. 
  ent. 
  soc. 
  Trans. 
  20:265 
  

  

  (description) 
  

   1895-97 
  Mesothemis 
  simplicicollis 
  Calvert, 
  N. 
  Y. 
  ent. 
  soc. 
  Jour. 
  3:48 
  

   and 
  5 
  : 
  94 
  (listed 
  from 
  New 
  York, 
  Westchester 
  co., 
  Ithaca 
  and 
  To- 
  

   wanda 
  creek) 
  

  

  1899 
  Mesothemis 
  simplicicollis, 
  Kellicott, 
  Odon. 
  Ohio, 
  p. 
  113 
  (descrip- 
  

  

  tion) 
  

  

  1900 
  Mesothemis 
  simplicicollis, 
  Williamson, 
  Dragon 
  flies 
  Ind. 
  p. 
  325 
  

  

  This 
  is 
  another 
  species 
  of 
  wide 
  distribution, 
  that 
  is 
  mucli 
  more 
  common 
  

   southward 
  and 
  westward: 
  a 
  single 
  specimen 
  was 
  seen 
  at 
  Saranac 
  Inn. 
  

   I 
  remember 
  having 
  seen 
  but 
  very 
  few 
  at 
  Ithaca. 
  I 
  bred 
  this 
  species 
  and 
  

   P. 
  longipennis 
  in 
  Illinois 
  in 
  1895. 
  The 
  imagos 
  of 
  this 
  species 
  have 
  

   more 
  of 
  the 
  gomphine 
  habit 
  of 
  squatting 
  on 
  the 
  ground 
  than 
  any 
  other 
  

   libellulines 
  known 
  to 
  me. 
  That 
  may 
  be 
  the 
  meaning 
  of 
  the 
  long 
  spines 
  

   on 
  the 
  hind 
  femora. 
  They 
  do 
  not 
  seek 
  the 
  topmost 
  twigs 
  of 
  reeds, 
  as 
  do 
  

   most 
  other 
  shore-frequenting 
  species, 
  but 
  settle 
  by 
  preference 
  in 
  some 
  

   bare 
  path, 
  or 
  aslant 
  a 
  board 
  at 
  the 
  edge 
  of 
  the 
  water. 
  The 
  nymphs 
  are 
  

   rapid 
  climbers 
  among 
  reed 
  stems. 
  In 
  life 
  their 
  eyes 
  are 
  yellowish 
  exter- 
  

   nally, 
  and 
  the 
  teeth 
  on 
  the 
  edges 
  of 
  the 
  labial 
  lobes 
  are 
  white. 
  The 
  

   bodies 
  of 
  the 
  nymphs 
  are 
  greenish 
  with 
  little 
  pattern 
  showing. 
  

  

  Nymph. 
  Measures 
  in 
  total 
  length 
  17 
  mm; 
  abdomen 
  9 
  mm; 
  hind 
  

   femur 
  5 
  mm 
  ; 
  width 
  of 
  head 
  5 
  mm, 
  of 
  abdomen 
  5.5 
  mm. 
  

  

  It 
  is 
  recognizable 
  at 
  a 
  glance 
  among 
  all 
  other 
  Hbelluline 
  nymphs 
  known 
  

   to 
  me 
  by 
  the 
  thickness 
  of 
  the 
  body, 
  the 
  bulging 
  prominence 
  of 
  the 
  eyes, 
  

   the 
  relative 
  brevity 
  of 
  the 
  abdomen, 
  and 
  the 
  decurved 
  appendages 
  at 
  the 
  

   apex 
  of 
  the 
  abdomen. 
  

  

  