﻿296 
  REPOET 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  fied, 
  mucli 
  more 
  tliau 
  the 
  Termitidse. 
  It 
  stands 
  alone, 
  and, 
  as 
  observed, 
  

   its 
  larvae 
  closely 
  resemble 
  the 
  Thysanuran 
  Japyx. 
  

  

  III. 
  Orthoptera. 
  — 
  After 
  the 
  elimination 
  of 
  the 
  Forficulidse 
  from 
  the 
  

   Orthoptera, 
  we 
  have 
  a 
  natural 
  and 
  easily 
  circumscribed 
  group. 
  Begin- 
  

   ning 
  with 
  decidedly 
  the 
  most 
  generalized 
  and 
  at 
  the 
  same 
  time 
  lowest 
  

   family, 
  the 
  Blattarise, 
  followed 
  by 
  the 
  MantidsB, 
  which 
  have 
  a 
  number 
  of 
  

   cliaracters 
  which 
  recall 
  the 
  Blattarise, 
  we 
  pass 
  up 
  through 
  the 
  Phasmidse 
  

   to 
  the 
  typical 
  family, 
  the 
  Acrydiij 
  then 
  succeed 
  the 
  Locustarise, 
  and 
  

   finally 
  the 
  Gryllidse, 
  which 
  on 
  the 
  whole 
  are 
  farthest 
  removed 
  from 
  the 
  

   stem^forms 
  of 
  the 
  order, 
  the 
  Cockroaches. 
  The 
  close 
  resemblance 
  of 
  a 
  

   larval 
  Cockroach 
  to 
  Lepisma 
  indicates 
  the 
  direct 
  descent 
  of 
  the 
  Ortho- 
  

   ptera 
  from 
  the 
  Cinurous 
  Thysanura. 
  

  

  IV. 
  Fseudoneuroptera. 
  — 
  This 
  is 
  the 
  most 
  heterogeneous 
  order 
  or 
  as- 
  

   semblage 
  of 
  insects. 
  While 
  it 
  is 
  comparatively 
  easy 
  to 
  circumscribe 
  

   the 
  Il^europtera 
  (taken 
  in 
  Erichson's 
  sense), 
  and 
  the 
  Orthoptera 
  as 
  here 
  

   restricted, 
  the 
  group 
  Fseudoneuroptera 
  is 
  remarkably 
  heterogeneous 
  and 
  

   elastic. 
  We 
  have 
  failed 
  to 
  satisfactorily 
  diagnose 
  the 
  order 
  as 
  a 
  whole. 
  

   The 
  Termitidse 
  connect 
  the 
  Orthoptera 
  ahd 
  Fseudoneuroptera 
  so 
  closely 
  

   that, 
  excepting 
  in 
  the 
  wings 
  and 
  other 
  peripheral 
  characters, 
  they 
  seem 
  

   but 
  a 
  family 
  removed 
  from 
  the 
  Blattarise. 
  For 
  example, 
  the 
  Termitidse 
  

   resemble 
  the 
  Blattarise 
  in 
  the 
  form 
  of 
  the 
  epicranium, 
  in 
  the 
  clypeus, 
  

   which 
  is 
  but 
  partially 
  differentiated 
  at 
  the 
  base 
  from 
  the 
  epicranium, 
  in 
  

   the 
  form 
  of 
  the 
  labrum, 
  and 
  the 
  small 
  eyes 
  as 
  well 
  as 
  the 
  mouth-jjarts. 
  

  

  In 
  the 
  thorax 
  the 
  Termitidae 
  ai)i)roach 
  the 
  Blattarise 
  in 
  the 
  undiffer- 
  

   entiated 
  scuta 
  of 
  the 
  meso- 
  and 
  metathorax 
  ; 
  while 
  the 
  pleurites 
  are 
  

   also 
  very 
  oblique 
  and 
  the 
  femora 
  are 
  flattened 
  and 
  ovate 
  in 
  form, 
  as 
  in 
  

   Blatta. 
  In 
  the 
  abdomen, 
  as 
  regards 
  the 
  form 
  of 
  the 
  tergites, 
  as 
  well 
  as 
  

   the 
  urites 
  and 
  pleurites, 
  besides 
  the 
  form 
  of 
  the 
  end 
  of 
  the 
  abdomen 
  and 
  

   of 
  the 
  cercopoda, 
  the 
  Termitidse 
  closely 
  approach 
  the 
  Blattarise. 
  The 
  

   degree 
  of 
  metamorphosis 
  is 
  also 
  the 
  same. 
  

  

  On 
  the 
  other 
  hand, 
  the 
  close 
  relationship 
  of 
  the 
  Termitidae 
  to 
  the 
  

   Embidse, 
  as 
  well 
  as 
  to 
  the 
  Fsocidse 
  and 
  also 
  the 
  Ferlidse, 
  and 
  the 
  close 
  

   resemblance 
  of 
  the 
  Ferlid 
  larvae 
  to 
  those 
  of 
  Odonata 
  and 
  Ephemerina, 
  

   forbid 
  our 
  removing 
  the 
  Flatyptera 
  from 
  the 
  Fseudoneuroptera. 
  

  

  We 
  conclude, 
  then, 
  that 
  the 
  Ephemerina, 
  Odonata, 
  Flatyptera, 
  as 
  

   well 
  as 
  Orthoptera 
  and 
  Dermatoptera 
  have 
  had 
  a 
  common 
  origin 
  from 
  

   some 
  Thysanuran 
  stock. 
  It 
  is 
  possible 
  that 
  these 
  five 
  groups 
  are 
  nearly 
  

   equivalent 
  and 
  should 
  take 
  the 
  rank 
  of 
  orders, 
  but 
  the 
  classification 
  we 
  

   have 
  given 
  in 
  the 
  tabular 
  view 
  on 
  p. 
  294 
  may 
  better 
  express 
  their 
  rela- 
  

   tions. 
  

  

  The 
  Odonata 
  and 
  Ephemerina 
  are, 
  as 
  regards 
  the 
  wings 
  and 
  meta- 
  

   morphosis, 
  a 
  good 
  deal 
  alike. 
  The 
  Ephemerina, 
  while 
  having 
  a 
  highly 
  

   concentrated 
  thorax, 
  are, 
  as 
  regards 
  the 
  mouth-parts 
  and 
  hind 
  wings, 
  

   degradational 
  forms, 
  the 
  result 
  of 
  probable 
  degeneration 
  from 
  a 
  primi- 
  

   tive, 
  lost 
  form. 
  From 
  what 
  group 
  the 
  Ephemerina 
  may 
  ^ave 
  originated 
  

   it 
  seems 
  to 
  us 
  impossible 
  to 
  conjecture. 
  

  

  