﻿280 
  LE 
  COJSTE 
  SYNOPSIS 
  OF 
  THE 
  

  

  aeneo-testaoeis, 
  fusco-aeneo 
  vel 
  seneo-viridibus, 
  con&rtim 
  rugose 
  punctatis 
  margine 
  tcstaceo, 
  tibiis 
  posticis 
  

   ad 
  apioem, 
  tarsisque 
  nigricantibus. 
  Long. 
  -34 
  — 
  -41. 
  

  

  Burm. 
  Lamell. 
  2, 
  2nd, 
  74. 
  

  

  Melohntha 
  linearis 
  Gyllenhal, 
  Schonherr, 
  Synon. 
  Ins. 
  3, 
  103. 
  

  

  ' 
  Dichelonycha 
  Backii 
  Kirby, 
  Fauna 
  Bor. 
  Am.'J 
  Burm. 
  Lamell. 
  2, 
  2nd. 
  

  

  Middle 
  States 
  and 
  Lake 
  Superior. 
  When 
  the 
  hair 
  of 
  the 
  thorax 
  has 
  been 
  removed, 
  

   as 
  is 
  sometimes 
  the 
  case, 
  this 
  species 
  may 
  be 
  known 
  by 
  the 
  very 
  dense, 
  but 
  not 
  fine 
  

   punctures 
  of 
  the 
  thorax, 
  the 
  base 
  of 
  which 
  is 
  wider 
  than 
  the 
  apex, 
  and 
  the 
  sides 
  angu- 
  

   lated 
  at 
  the 
  middle. 
  There 
  appears 
  to 
  be 
  a 
  variation 
  in 
  the 
  form 
  of 
  the 
  basal 
  angles, 
  

   sometimes 
  they 
  are 
  subacute 
  and 
  moderately 
  prominent, 
  sometimes 
  rectangular, 
  and 
  

   sometimes 
  obtuse 
  ; 
  they 
  are 
  never 
  very 
  acute 
  and 
  prominent 
  as 
  in 
  D. 
  elongata. 
  It 
  is 
  

   possible 
  that 
  by 
  comparing 
  specimens 
  from 
  different 
  localities 
  several 
  closely 
  allied 
  

   species 
  here 
  confounded 
  together 
  may 
  be 
  separated. 
  

  

  One 
  female 
  from 
  Maryland 
  has 
  the 
  posterior 
  angles 
  more 
  prominent, 
  and 
  the 
  elytra 
  

   of 
  a 
  dull 
  brownish 
  bronze 
  color. 
  The 
  thorax 
  appears 
  more 
  coarsely 
  punctured, 
  but 
  

   it 
  is 
  unsafe 
  to 
  propose 
  a 
  new 
  species 
  upon 
  this 
  single 
  specimen. 
  

  

  5. 
  D. 
  f 
  u 
  1 
  gi 
  d 
  a, 
  picoa, 
  elongata, 
  capite 
  thoraceque 
  piceis 
  vel 
  piceo-rufis, 
  illo 
  tenuiter 
  marginato 
  confluenter, 
  

  

  hoc 
  fortius 
  medio 
  minus 
  dense 
  punctato, 
  pilis 
  grossis 
  asneo-flavis 
  dense 
  vestito, 
  lateribus 
  subangulatis, 
  

   postice 
  oblique 
  subsinuatis, 
  angulis 
  posticis 
  subrectis, 
  elytris 
  fortiter 
  punctatis, 
  vix 
  trilineatis, 
  breviter 
  

   pubescentibus, 
  viridiajneis, 
  vix 
  lineatis, 
  margine 
  tcstaceis, 
  antennis 
  pedibusque 
  flavis, 
  tibiis 
  tarsisque 
  

   infuscatis. 
  Long. 
  -37. 
  

  

  Steilacoom, 
  Washington 
  Territory, 
  Dr. 
  Suckley. 
  Allied 
  closely 
  to 
  the 
  preceding, 
  

   but 
  the 
  thorax 
  is 
  less 
  densely 
  and 
  more 
  strongly 
  punctured, 
  less 
  suddenly 
  angulated 
  

   on 
  the 
  sides, 
  and 
  less 
  narrowed 
  behind, 
  and 
  the 
  reflexed 
  margin 
  of 
  the 
  clypeus 
  is 
  very 
  

   narrow. 
  

  

  6. 
  D. 
  Backii, 
  nigro-picea, 
  elongata, 
  capite 
  confluenter 
  punctato, 
  fortius 
  marginato, 
  thorace 
  fortiter 
  sat 
  

  

  dense 
  punctato, 
  spatio 
  utrinque 
  sublrevi 
  (dense 
  fortius 
  pubescente 
  ?) 
  lateribus 
  rotundatis 
  subangulatis, 
  

  

  angulis 
  posticis 
  obtusis, 
  elytris 
  lrete 
  viridiaeneis, 
  margine 
  testaceo, 
  rugose 
  punctatis 
  sublineatis, 
  antennis 
  

  

  pedibusque 
  nigro 
  piceis, 
  his 
  rufo-tinctis. 
  Long. 
  -33 
  — 
  -39. 
  

  

  Kirby, 
  Fauna 
  Bor. 
  Am. 
  4, 
  134, 
  tab. 
  2, 
  fig. 
  6. 
  

   North 
  side 
  of 
  Lake 
  Superior. 
  Burmeister 
  places 
  this 
  as 
  synonymous 
  with 
  D. 
  linearis 
  ; 
  

   my 
  specimens 
  are 
  however 
  clearly 
  different, 
  not 
  only 
  by 
  the 
  dark 
  colored 
  antenna?, 
  

   but 
  by 
  the 
  more 
  strongly 
  margined 
  clypeus, 
  and 
  by 
  the 
  more 
  coarsely 
  and 
  less 
  densely 
  

   punctured 
  thorax 
  ; 
  on 
  each 
  side 
  of 
  the 
  disc 
  anteriorly, 
  near 
  the 
  lateral 
  fovea 
  is 
  an 
  

   indistinct 
  space 
  which 
  is 
  less 
  punctured 
  ; 
  the 
  sides 
  are 
  less 
  angulated, 
  and 
  not 
  at 
  all 
  

   sinuate 
  behind. 
  The 
  specimens 
  were 
  found 
  floating 
  in 
  the 
  lake, 
  and 
  had 
  lost 
  nearly 
  

   all 
  the 
  pubescence 
  ; 
  from 
  the 
  appearance 
  of 
  what 
  remains 
  on 
  the 
  side 
  of 
  the 
  thorax, 
  

   I 
  believe 
  that 
  the 
  hair 
  was 
  coarse 
  and 
  probably 
  dense 
  as 
  in 
  D. 
  linearis. 
  Kirby 
  doe9 
  

   not 
  mention 
  this 
  character, 
  but 
  it 
  may 
  have 
  been 
  lost 
  in 
  the 
  alcohol 
  in 
  which 
  the 
  

   specimens 
  were 
  preserved 
  ; 
  the 
  hair 
  of 
  the 
  under 
  surface, 
  being 
  better 
  protected, 
  has 
  

   been 
  preserved 
  in 
  both 
  his 
  specimens 
  and 
  mine. 
  

  

  