﻿610 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  vol.44. 
  

  

  which 
  in 
  this 
  sex 
  are 
  hard 
  to 
  separate 
  diagnostically, 
  and 
  more 
  mate- 
  

   rial 
  and 
  study 
  is 
  necessary 
  for 
  the 
  preparation 
  of 
  a 
  key 
  to 
  separate 
  

   them 
  on 
  this 
  sex 
  alone. 
  The 
  following 
  key, 
  based 
  mostly 
  on 
  the 
  

   males, 
  will 
  prove 
  of 
  help 
  in 
  the 
  determination 
  of 
  these 
  walking 
  

   sticks. 
  

  

  Key 
  to 
  males 
  ofgentLS 
  Diapheromera. 
  

   a^. 
  Cerci 
  incurved. 
  

  

  6'. 
  Cerci 
  cylindrical, 
  with 
  a 
  basal 
  tooth 
  or 
  tubercle. 
  

   c^. 
  Cerci 
  with 
  an 
  acute 
  and 
  slender 
  basal 
  tooth. 
  

   d^. 
  Ninth 
  segment 
  of 
  the 
  abdomen 
  scarcely 
  longer 
  than 
  the 
  greatest 
  width. 
  

  

  vein 
  Walsh. 
  

   cP. 
  Ninth 
  abdominal 
  segment 
  distinctly 
  longer 
  than 
  the 
  greatest 
  width. 
  

  

  persimilis 
  Caudell. 
  

   c?. 
  Cerci 
  with 
  a 
  blunt 
  basal 
  tooth 
  or 
  tubercle. 
  

   d^. 
  Seventh 
  and 
  ninth 
  segments 
  of 
  the 
  abdomen 
  subequal 
  in 
  length. 
  

  

  «i. 
  Ninth 
  segment 
  of 
  the 
  abdomen 
  distinctly 
  longer 
  than 
  the 
  greatest 
  width; 
  

   • 
  inner 
  ventro-lateral 
  carina 
  of 
  the 
  hind 
  femora 
  with 
  very 
  minute 
  ser- 
  

  

  rations; 
  cerci 
  of 
  the 
  female 
  as 
  long 
  as 
  the 
  eighth 
  segment 
  of 
  the 
  abdomen. 
  

  

  persimilis 
  Caudell. 
  

  

  e^. 
  Ninth 
  segment 
  of 
  the 
  abdomen 
  scarcely 
  or 
  no 
  longer 
  than 
  the 
  greatest 
  

  

  width; 
  inner 
  ventro-lateral 
  carina 
  of 
  the 
  posterior 
  femora 
  smooth; 
  cerci 
  of 
  

  

  the 
  female 
  about 
  one-half 
  as 
  long 
  as 
  the 
  eighth 
  segment 
  of 
  the 
  abdomen. 
  

  

  arizonensis 
  Caudell. 
  

  

  d^. 
  Seventh 
  segment 
  of 
  the 
  abdomen 
  distinctly 
  longer 
  than 
  the 
  ninth 
  (cerci 
  of 
  

  

  female 
  about 
  one-half 
  as 
  long 
  as 
  the 
  eighth 
  segment 
  of 
  the 
  abdomen.) 
  

  

  femorata 
  Say. 
  

  

  h^. 
  Cerci 
  strongly 
  compressed, 
  without 
  any 
  basal 
  tooth 
  or 
  tubercle 
  . 
  . 
  Carolina 
  Scudder. 
  

  

  a^. 
  Cerci 
  rigidly 
  straight, 
  or 
  more 
  or 
  less 
  curled 
  in 
  drying 
  mesillana 
  Scudder. 
  

  

  D. 
  persimilis 
  shows 
  some 
  considerable 
  variation 
  in 
  the 
  basal 
  tooth 
  

   of 
  the 
  cerci 
  of 
  the 
  male. 
  This 
  is 
  sometimes 
  sharp, 
  like 
  in 
  velii, 
  and 
  

   sometimes 
  apparently 
  nearly 
  as 
  blunt 
  as 
  in 
  femorata. 
  But 
  the 
  com- 
  

   parative 
  lengths 
  of 
  the 
  last 
  segments 
  of 
  the 
  abdomen 
  of 
  the 
  male 
  

   will 
  separate 
  it 
  from 
  velii 
  or 
  femorata, 
  and 
  the 
  long 
  cerci 
  of 
  the 
  female 
  

   prohibits 
  it 
  from 
  being 
  confused 
  with 
  the 
  latter 
  species. 
  

  

  I 
  have 
  two 
  male 
  specimens 
  which 
  I 
  take 
  to 
  be 
  D. 
  mesillana. 
  They 
  

   are 
  nymphs; 
  and 
  come 
  from 
  Victoria, 
  Texas, 
  and 
  I 
  have 
  an 
  adult 
  male 
  

   from 
  Columbus, 
  Texas. 
  Specimens 
  from 
  Brownsville, 
  Texas, 
  are 
  in 
  the 
  

   Museum 
  of 
  the 
  Brooklyn 
  Institute 
  of 
  Arts 
  and 
  Sciences, 
  and 
  in 
  the 
  

   Scudder 
  collection 
  I 
  find 
  a 
  male 
  from 
  Kansas 
  which 
  I 
  determine 
  as 
  

   this 
  species. 
  In 
  this 
  specimen 
  from 
  Kansas 
  the 
  cerci 
  are 
  not 
  con- 
  

   cave 
  on 
  the 
  umer 
  side, 
  and 
  it 
  is 
  doubtful 
  if 
  any 
  are 
  lq 
  life, 
  as 
  the 
  cerci 
  

   of 
  female 
  specimens 
  of 
  most 
  species 
  are 
  naturally 
  round 
  when 
  fresh 
  

   but 
  flatten 
  out 
  in 
  drying. 
  The 
  cerci 
  of 
  the 
  male 
  of 
  mesillana 
  beiag 
  

   straight, 
  like 
  that 
  of 
  the 
  female 
  of 
  most 
  species, 
  is 
  very 
  likely 
  natu- 
  

   rally 
  round. 
  More 
  investigation 
  with 
  fresh 
  material 
  is 
  necessary 
  to 
  

   make 
  this 
  certain. 
  If 
  the 
  cerci 
  of 
  this 
  species 
  are 
  actually 
  concave 
  

   on 
  the 
  inner 
  side, 
  the 
  round 
  shape 
  of 
  those 
  of 
  this 
  Kansas 
  specimen 
  

   must 
  be 
  attributed 
  to 
  the 
  specimen 
  being 
  originally 
  preserved 
  in 
  

   spirits, 
  which 
  it 
  very 
  clearly 
  was. 
  

  

  