﻿170 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  A. 
  A. 
  Prosternum 
  unarmed. 
  

  

  a. 
  The 
  stylos 
  of 
  the 
  subgenital 
  plate 
  of 
  the 
  male 
  fixed 
  (not 
  movable). 
  

  

  Steiroxys. 
  Herm. 
  

   aa. 
  Styles 
  of 
  the 
  subgenital 
  plate 
  of 
  the 
  males 
  articulated 
  (movable). 
  

  

  1). 
  Median 
  carina 
  of 
  the 
  pronotum 
  distinct 
  throughout 
  Decticus. 
  Serv, 
  

  

  5&. 
  Median 
  carina 
  of 
  the 
  pronotum 
  wanting 
  or 
  visible 
  only 
  on 
  the 
  posterior 
  

   portion, 
  

   c. 
  Dorsum 
  of 
  the 
  pronotum 
  rugose 
  ; 
  elytra 
  squamaeforin 
  ; 
  wings 
  absent. 
  

  

  Psorodonotus. 
  Burm. 
  

   cc. 
  Dorsum 
  of 
  the 
  pronotum 
  smooth. 
  

  

  d. 
  . 
  Elytra 
  short 
  but 
  not 
  squamseform 
  Platycleis. 
  Fieb. 
  

  

  dd. 
  Elytra 
  squamseform 
  ; 
  pronotum 
  without 
  distinct 
  lateral 
  carinas. 
  

  

  e. 
  Anterior 
  tibiae 
  with 
  but 
  three 
  or 
  four 
  spines 
  in 
  front 
  ; 
  in 
  one 
  

  

  row 
  Thamnotrizon. 
  Fisch. 
  

  

  ee. 
  Anterior 
  tibiae 
  with 
  six 
  to 
  eight 
  spines 
  in 
  front 
  ; 
  in 
  two 
  rows. 
  

  

  Andbrus. 
  Hald. 
  

  

  From 
  this 
  table 
  it 
  will 
  be 
  seen, 
  as 
  stated, 
  that 
  A. 
  Haldemanii 
  Girard 
  

   does 
  not 
  belong 
  to 
  the 
  genus 
  in 
  which 
  it 
  was 
  originally 
  placed. 
  For 
  

   this 
  reason 
  we 
  have 
  omitted 
  it 
  from 
  the 
  present 
  paper. 
  

  

  We 
  may 
  note 
  in 
  passing 
  that 
  according 
  to 
  the 
  arrangement 
  of 
  the 
  

   genera 
  as 
  here 
  given, 
  Thamnotrizon 
  scabricollis 
  Thos., 
  which 
  appears 
  to 
  

   be 
  closely 
  allied 
  to 
  this 
  genus, 
  and 
  will 
  by 
  most 
  unscientific 
  observers 
  

   be 
  taken 
  for 
  A. 
  purpurascens, 
  must 
  be 
  removed 
  to 
  the 
  genus 
  Psoro- 
  

   donotus. 
  

  

  The 
  genus 
  Andbrus 
  appears 
  to 
  be 
  represented 
  only 
  in 
  that 
  portion 
  of 
  

   North 
  America 
  north 
  of 
  Mexico 
  and 
  west 
  of 
  the 
  Mississippi. 
  Four 
  spe- 
  

   cies 
  are 
  mentioned, 
  A. 
  simplex 
  Hald., 
  A. 
  purpurascens 
  Uhl., 
  A. 
  similis 
  

   Scudd., 
  and 
  A. 
  coloradus 
  Thos. 
  The 
  third, 
  A. 
  similis 
  Scudd., 
  appears 
  

   to 
  be 
  but 
  a 
  variety 
  of 
  A. 
  purpurascens 
  ; 
  we 
  therefore 
  have 
  but 
  three 
  dis- 
  

   tinct 
  species. 
  

  

  These 
  may 
  be 
  distinguished 
  from 
  each 
  other 
  by 
  the 
  following 
  charac- 
  

   ters 
  : 
  A. 
  coloradus 
  is 
  the 
  smallest, 
  and 
  has 
  the 
  abdomen 
  distinctly 
  marked 
  

   by 
  transverse 
  bands. 
  A. 
  purpurascens, 
  dark 
  purplish-brown, 
  mottled 
  

   with 
  yellow. 
  A. 
  simplex, 
  dark 
  shining 
  brown. 
  This 
  species 
  varies 
  con- 
  

   siderably 
  in 
  color, 
  being 
  found 
  of 
  every 
  shade 
  from 
  light 
  brownish-yel- 
  

   low 
  to 
  almost 
  entirely 
  black 
  ; 
  specimens 
  are 
  sometimes 
  found 
  that 
  are 
  

   partly 
  yellow 
  and 
  partly 
  black 
  or 
  dark-purple. 
  

  

  ANATOMY 
  OF 
  ANABRUS. 
  

  

  External 
  anatomy 
  (Figs. 
  3, 
  4). 
  — 
  The 
  following 
  account 
  is 
  based 
  on 
  the 
  

   external 
  structure 
  of 
  Anabrus 
  simplex. 
  

  

  The 
  head. 
  — 
  In 
  these 
  crickets, 
  the 
  first 
  region 
  of 
  the 
  body, 
  or 
  head, 
  is 
  

   large 
  and 
  rounded, 
  the 
  epicranium, 
  or 
  piece 
  composing 
  the 
  bulk 
  of 
  the 
  

   head, 
  being 
  large, 
  while 
  the 
  eyes 
  are 
  small 
  and 
  situated 
  far 
  apart; 
  be- 
  

   tween 
  them 
  the 
  vertex 
  rises 
  into 
  a 
  shield-shaped 
  prominence, 
  on 
  each 
  

   side 
  of 
  the 
  base 
  of 
  which 
  is 
  situated 
  a 
  simple 
  eye 
  (ocellus), 
  forming 
  two 
  

   pale, 
  oval, 
  roundish 
  spots 
  easily 
  overlooked. 
  The 
  third 
  ocellus 
  is 
  more 
  

  

  