﻿66 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  westward 
  extension, 
  suffer 
  most. 
  It 
  is 
  from 
  this 
  direction 
  instead 
  of 
  

   from 
  Africa 
  that 
  the 
  hordes 
  come 
  which 
  visit 
  Italy 
  and 
  occasionally 
  

   penetrate 
  to 
  Sicily. 
  

  

  We 
  may 
  remark 
  here 
  that 
  some 
  of 
  Wallace's 
  boundary 
  lines 
  in 
  this 
  

   region 
  appear 
  to 
  have 
  been 
  somewhat 
  arbitrarily 
  drawn, 
  and 
  in 
  one 
  case 
  

   he 
  appears 
  to 
  have 
  been 
  guided 
  too 
  much 
  by 
  the 
  distribution 
  of 
  a 
  single 
  

   class 
  of 
  animals. 
  If 
  his 
  line 
  between 
  1 
  and 
  3, 
  instead 
  of 
  following 
  the 
  

   Ural 
  Bange 
  as 
  it 
  does 
  on 
  his 
  map, 
  had 
  been 
  traced 
  along 
  the 
  valley 
  of 
  

   the 
  Irtish, 
  which 
  he 
  gives 
  as 
  the 
  more 
  correct 
  eastern 
  boundary 
  of 
  the 
  

   European 
  subregion, 
  it 
  would 
  then 
  correspond 
  almost 
  exactly 
  with 
  the 
  

   eastern 
  boundary 
  of 
  the 
  pasture 
  area 
  described. 
  

  

  While 
  there 
  are 
  some 
  strong 
  reasons 
  for 
  uniting 
  the 
  northern 
  and 
  

   southern 
  shores 
  of 
  the 
  Mediterranean 
  into 
  one 
  faunal 
  district, 
  there 
  are 
  

   equally 
  good 
  reasons 
  for 
  considering 
  the 
  two 
  parts 
  as 
  representing 
  two 
  

   faunal 
  areas, 
  less 
  distinct, 
  it 
  is 
  true, 
  than 
  his 
  subregions, 
  but 
  not 
  so 
  

   homogeneous 
  as 
  the 
  parts 
  of 
  most 
  of 
  the 
  other 
  subregions. 
  In 
  fact, 
  it 
  

   is 
  still 
  a 
  matter 
  of 
  doubt 
  whether 
  it 
  would 
  not 
  have 
  been 
  better 
  to 
  con- 
  

   sider 
  these 
  two 
  parts 
  as 
  separate 
  subregions. 
  If 
  this 
  be 
  done, 
  we 
  will 
  

   then 
  find 
  the 
  locust 
  distribution 
  corresponding 
  almost 
  exactly 
  with 
  the 
  

   faunal 
  subregions, 
  or 
  that 
  their 
  permanent 
  distribution 
  is 
  limited 
  by 
  the 
  

   boundaries 
  of 
  their 
  respective 
  faunal 
  areas. 
  The 
  European 
  subregion, 
  

   if 
  extended 
  as 
  indicated, 
  and 
  as 
  suggested 
  by 
  Wallace 
  in 
  his 
  text, 
  will 
  

   embrace 
  what 
  we 
  are 
  inclined 
  to 
  think 
  is 
  really 
  the 
  home 
  of 
  P. 
  migra- 
  

   tortus. 
  This 
  is 
  the 
  great 
  pasture 
  region, 
  and 
  its 
  locust 
  is 
  (Edipodsean. 
  

   The 
  Mediterranean 
  district, 
  as 
  given 
  by 
  Wallace, 
  is 
  the 
  region 
  of 
  mount- 
  

   ains 
  and 
  deserts 
  ; 
  the 
  northern 
  section, 
  which 
  is 
  elevated 
  and 
  broken, 
  has 
  

   its 
  peculiar 
  locust, 
  the 
  Caloptenus 
  italicus; 
  the 
  southern, 
  or 
  desert 
  por- 
  

   tion, 
  has 
  its 
  own 
  migratory 
  species, 
  Acridium 
  peregrinum 
  ; 
  the 
  two 
  be- 
  

   longing 
  to 
  the 
  Acridian 
  group 
  of 
  the 
  family 
  Acrididce. 
  

  

  There 
  is 
  a 
  fact 
  which 
  presents 
  itself 
  at 
  this 
  point 
  that, 
  although 
  not 
  

   directly 
  necessary 
  to 
  this 
  discussion, 
  is 
  worthy 
  of 
  notice, 
  and 
  may 
  assist 
  

   in 
  solving 
  the 
  problem 
  of 
  locust-distribution 
  in 
  the 
  Eastern 
  Continent, 
  

   Considering 
  the 
  Mediterranean 
  subregion 
  of 
  Wallace 
  as 
  two 
  sections, 
  

   Southwestern 
  Asia, 
  or 
  the 
  region 
  bounded 
  by 
  the 
  Caspian, 
  Black, 
  and 
  

   Mediterranean 
  Seas 
  and 
  Persian 
  Gulf, 
  forms 
  the 
  point 
  of 
  union 
  between 
  

   the 
  three 
  locust 
  districts, 
  where 
  we 
  may 
  naturally 
  expect 
  a 
  commin- 
  

   gling 
  of 
  the 
  three 
  species 
  in 
  their 
  migratory 
  movements. 
  That 
  such 
  is 
  

   the 
  fact 
  those 
  who 
  have 
  attempted 
  to 
  trace 
  the 
  areas 
  of 
  distribution 
  of 
  

   the 
  two 
  great 
  oriental 
  species 
  know 
  too 
  well. 
  

  

  Here, 
  in 
  fact, 
  is 
  the 
  meeting 
  ground 
  of 
  the 
  three 
  true 
  locusts 
  of 
  the 
  

   Eastern 
  Continent 
  ; 
  the 
  area 
  of 
  the 
  P. 
  migratorius 
  pressing 
  into 
  it 
  on 
  

   the 
  north 
  ; 
  that 
  of 
  A. 
  peregrinum 
  on 
  the 
  south 
  and 
  southwest 
  ; 
  while 
  

   that 
  of 
  G. 
  italicus 
  is 
  thrust 
  like 
  a 
  wedge 
  between 
  the 
  two. 
  

  

  As 
  an 
  evidence 
  of 
  the 
  commingling 
  on 
  this 
  debatable 
  ground 
  of 
  

   Western 
  Asia, 
  we 
  have 
  only 
  to 
  call 
  attention 
  to 
  the 
  statements 
  of 
  some 
  

   of 
  the 
  authorities 
  already 
  quoted. 
  

  

  