﻿NO. 
  1124. 
  BEVISIOX 
  OF 
  THE 
  MELAXOPLI—SCrDDER. 
  123 
  

  

  PJioefaUotes, 
  and 
  Oedaleonotus, 
  each 
  of 
  wbicli 
  is 
  represented 
  by 
  a 
  single 
  

   species, 
  I 
  have 
  treated 
  tliis 
  matter 
  more 
  fnlly 
  in 
  the 
  Introduction. 
  

  

  The 
  present 
  genus, 
  so 
  richly 
  endowed 
  witb 
  species, 
  is 
  naturally 
  very 
  

   widely 
  distributed, 
  though 
  so 
  far 
  as 
  known 
  it 
  is 
  completely 
  confined 
  to 
  

   the 
  continent 
  of 
  North 
  America, 
  and 
  even 
  does 
  not 
  occur, 
  so 
  far 
  as 
  

   reported,^ 
  south 
  of 
  Mexico. 
  Within 
  this 
  region 
  it 
  is 
  as 
  Avidespread 
  as 
  

   all 
  the 
  other 
  genera 
  combined. 
  It 
  extends 
  from 
  the 
  arctic 
  circle 
  in 
  

   Alaska 
  and 
  on 
  the 
  Mackenzie 
  Eiver, 
  and 
  from 
  northern 
  Labrador 
  and 
  

   perhaps 
  southern 
  Greenland 
  on 
  the 
  north, 
  to 
  the 
  extremity 
  of 
  Florida 
  

   and 
  southern 
  Mexico 
  on 
  the 
  south, 
  and 
  from 
  the 
  Atlantic 
  to 
  the 
  Pacific. 
  

   It 
  is, 
  however, 
  far 
  richer 
  in 
  species 
  in 
  the 
  west 
  than 
  in 
  the 
  east. 
  Only 
  

   seventeen 
  of 
  the 
  one 
  hundred 
  and 
  thirty-one 
  species 
  are 
  found 
  exclusively 
  

   east 
  of 
  the 
  Mississippi 
  Elver, 
  though 
  four 
  other 
  eastern 
  species 
  barely 
  

   cross 
  it; 
  while 
  in 
  the 
  Eocky 
  Mountain 
  region 
  and 
  west 
  of 
  it, 
  and 
  there 
  

   only, 
  forty-nine- 
  species 
  are 
  known, 
  while 
  thirty-two 
  others 
  are 
  found 
  

   onlywestof 
  the 
  Mississippi 
  Eiver 
  and 
  seven 
  western 
  species 
  barely 
  

   cross 
  it 
  to 
  the 
  east; 
  six 
  species, 
  as 
  stated 
  in 
  our 
  introduction, 
  range 
  

   from 
  Atlantic 
  to 
  Pacific; 
  one 
  occurs 
  only 
  north 
  of 
  our 
  national 
  bound- 
  

   aries 
  in 
  Labrador, 
  while 
  nineteen 
  others 
  inhabit 
  Canada; 
  twelve 
  are 
  

   found 
  only 
  in 
  Mexico, 
  with 
  ten 
  others 
  which 
  it 
  possesses 
  in 
  common 
  

   with 
  the 
  United 
  States. 
  

  

  These 
  figures 
  show 
  the 
  western 
  preponderance 
  of 
  the 
  species 
  better 
  

   than 
  any 
  summary 
  of 
  the 
  twenty-eight 
  groups 
  into 
  which 
  I 
  have 
  divided 
  

   the 
  genus, 
  which, 
  besides 
  being 
  rather 
  unequal 
  in 
  the 
  number 
  of 
  con- 
  

   tained 
  species, 
  often 
  show 
  an 
  extremely 
  wide 
  distribution 
  or 
  more 
  than 
  

   one 
  center 
  of 
  distribution, 
  in 
  the 
  latter 
  case 
  indicating, 
  perhaps, 
  the 
  

   imperfection 
  of 
  the 
  grouping-. 
  Still, 
  leaving 
  out 
  the 
  five 
  groups, 
  each 
  

   of 
  which 
  contains 
  one 
  or 
  more 
  transcontinental 
  species, 
  it 
  will 
  be 
  noted 
  

   that 
  there 
  are 
  three 
  others 
  which 
  compass 
  the 
  continent 
  — 
  the 
  mancus 
  

   (five 
  species), 
  plebeius 
  (five 
  vspecies), 
  and 
  robustus 
  (five 
  species) 
  series. 
  

   Of 
  the 
  twenty 
  remaining, 
  one-half, 
  viz, 
  the 
  flabellifer 
  (six 
  species), 
  bow- 
  

   ditcbi 
  (six 
  species), 
  glaucipes 
  (two 
  species), 
  utahensis 
  (three 
  species), 
  

   devastator 
  (eight 
  species), 
  aridus 
  (three 
  species), 
  rusticus 
  (seven 
  spe- 
  

   cies), 
  borckii 
  (six 
  species), 
  cinereus 
  (six 
  species), 
  and 
  packardii 
  (five 
  

   si>ecies) 
  series 
  — 
  extend 
  westward 
  to 
  the 
  Pacific; 
  while 
  only 
  five 
  — 
  the 
  

   impudicus 
  (one 
  species), 
  dawsoni 
  (seven 
  species), 
  puer 
  (two 
  species), 
  

   inoruiitus 
  (three 
  species), 
  and 
  punctulatus 
  (two 
  species) 
  series 
  — 
  reach 
  

   eastward 
  to 
  the 
  Atlantic 
  coast; 
  and 
  the 
  remaining 
  five 
  — 
  the 
  lakinus 
  

   (three 
  species), 
  indigens 
  (one 
  species), 
  alleni 
  (two 
  species', 
  augustipen- 
  

   nis 
  (four 
  species), 
  and 
  texanus 
  (five 
  species) 
  series 
  — 
  are 
  found 
  exclu- 
  

   sively, 
  or 
  almost 
  exclusively, 
  west 
  of 
  the 
  Mississippi 
  Eiver. 
  

  

  One-half 
  of 
  the 
  series 
  are 
  represented 
  in 
  Mexico, 
  showing 
  rather 
  

  

  'One 
  species, 
  M. 
  horealis, 
  is 
  reported, 
  in 
  lift., 
  by 
  Brnnner 
  to 
  occur 
  at 
  Valdivia, 
  

   Chile; 
  as 
  its 
  only 
  otbei' 
  kuowii 
  localities 
  arc 
  in 
  tlie 
  arctic 
  regions, 
  I 
  am 
  iuclineil 
  

   to 
  doubt 
  the 
  correctness 
  of 
  tlie 
  determination, 
  and 
  presume 
  the 
  material 
  to 
  be 
  

   insufficient. 
  

  

  