﻿500 
  REVISION 
  OF 
  THE 
  ELATERID^E 
  

  

  Of 
  the 
  species 
  described 
  in 
  this 
  essay, 
  D. 
  mancus 
  and 
  D. 
  pubescens 
  differ 
  from 
  the 
  

   others 
  in 
  having 
  the 
  mouth 
  entirely 
  closed 
  by 
  the 
  sternum, 
  and 
  in 
  this 
  respect 
  agree 
  

   with 
  Agriotes 
  segetis 
  of 
  Europe. 
  The 
  basal 
  fissures 
  are 
  more 
  elongated 
  than 
  in 
  the 
  other 
  

   species, 
  and 
  present 
  in 
  certain 
  lights 
  the 
  appearance 
  of 
  elevated 
  lines: 
  it 
  might 
  be 
  doubted 
  

   which 
  of 
  the 
  two 
  is 
  the 
  real 
  El. 
  maneus 
  Say, 
  but 
  as 
  it 
  is 
  compared 
  with 
  El. 
  convexus, 
  evi- 
  

   dently 
  a 
  robust 
  species 
  of 
  Cardiophorus, 
  I 
  have 
  given 
  the 
  preference 
  to 
  that 
  having 
  the 
  

   more 
  robust 
  form. 
  

  

  D. 
  pauper, 
  D. 
  subustus, 
  D. 
  bigeminatus, 
  D. 
  oblongicollis, 
  D. 
  isabellinus, 
  and 
  D. 
  avulsus, 
  

   agree 
  closely 
  in 
  characters 
  with 
  the 
  European 
  D. 
  marginatum, 
  which 
  is 
  the 
  type 
  of 
  Esch- 
  

   scholtz's 
  genus 
  Dolopius: 
  in 
  them 
  the 
  posterior 
  coxa3 
  are 
  somewhat 
  suddenly 
  dilated 
  in- 
  

   ternally; 
  in 
  the 
  remaining 
  species 
  the 
  cox* 
  are 
  hardly 
  wider 
  internally, 
  and 
  the 
  second 
  

   and 
  third 
  joints 
  of 
  the 
  antenna) 
  are 
  variable 
  in 
  their 
  proportions: 
  united 
  together, 
  they 
  are 
  

   longer 
  than 
  the 
  fourth; 
  they 
  are 
  equal 
  in 
  size, 
  or 
  nearly 
  so; 
  but 
  in 
  D. 
  limosus 
  the 
  second 
  

   appears 
  distinctly 
  longer 
  than 
  the 
  third; 
  the 
  suture 
  of 
  the 
  prosternum 
  is 
  more 
  or 
  less 
  ex- 
  

   cavated 
  anteriorly, 
  and 
  in 
  all 
  of 
  them 
  to 
  a 
  greater 
  extent 
  than 
  in 
  the 
  European 
  D. 
  margi- 
  

   natus. 
  

  

  Under 
  these 
  circumstances, 
  I 
  did 
  not 
  feel 
  justified 
  in 
  separating 
  such 
  closely 
  allied 
  spe- 
  

   cies 
  into 
  different 
  genera, 
  though 
  I 
  confess 
  that 
  the 
  following 
  arrangement 
  of 
  the 
  species 
  

   described 
  would 
  be 
  more 
  natural 
  than 
  the 
  one 
  proposed 
  in 
  the 
  text, 
  although 
  the 
  thickened 
  

   and 
  emarginate 
  mandibles 
  separate 
  A. 
  mancus 
  from 
  all 
  the 
  other 
  species, 
  both 
  native 
  and 
  

   foreign, 
  that 
  I 
  have 
  examined: 
  

  

  A. 
  Sternum 
  subtus 
  os 
  omnino 
  obtegens: 
  A. 
  mancus 
  and 
  pubescens. 
  

  

  B. 
  Os 
  subtus 
  plus 
  minusve 
  liberum: 
  

  

  Coxae 
  po-sticce 
  intus 
  vix 
  latiores 
  : 
  A. 
  collaris, 
  fucosus, 
  sordidus. 
  

  

  Coxae 
  posticus 
  intus 
  modice, 
  subgradatim 
  angustate: 
  A. 
  avulsus, 
  sordidus, 
  stabilis, 
  limosus. 
  

  

  Coxce 
  posticae 
  intus 
  modice 
  fere 
  subito 
  angustatae 
  : 
  

  

  Antennae 
  articulis 
  2 
  et 
  3 
  coniunctis 
  4 
  t0 
  brevioribus 
  : 
  A. 
  isabellinus 
  and 
  oblongicollis. 
  

  

  Antennas 
  articulis 
  2 
  et 
  3 
  coniunctis 
  4 
  t0 
  longioribus, 
  (frons 
  apice 
  subangulata 
  :) 
  A. 
  pauper, 
  

   subustus, 
  bigeminatus. 
  

  

  The 
  following 
  note 
  from 
  Dr. 
  Harris 
  will 
  explain 
  the 
  different 
  views 
  taken 
  by 
  us 
  of 
  the 
  

   nomenclature 
  of 
  the 
  species, 
  considered 
  by 
  Dr. 
  Harris 
  as 
  EI. 
  obesus, 
  and 
  by 
  me 
  as 
  Elater 
  

   mancus. 
  

  

  "The 
  species 
  which 
  Dr. 
  Le 
  Conte 
  refers 
  to 
  Elater 
  mancus 
  of 
  Say, 
  is 
  strictly 
  congerical 
  with 
  the 
  

   European 
  species 
  segetis 
  Gyll. 
  (striatus 
  Fabr.) 
  variabilis 
  F., 
  and 
  sputator 
  F., 
  with 
  all 
  of 
  which 
  it 
  has 
  

   been 
  carefully 
  compared. 
  These 
  species 
  belong 
  to 
  the 
  genus 
  Agriotes 
  of 
  Eschscholtz 
  and 
  of 
  La- 
  

   treille. 
  The 
  insect 
  in 
  question 
  is 
  to 
  be 
  found 
  in 
  the 
  'Catalogue 
  of 
  the 
  insects 
  of 
  Massachusetts,' 
  ap- 
  

   pended 
  to 
  the 
  2d 
  edition 
  of 
  Hitchcock's 
  Report, 
  under 
  the 
  name 
  E. 
  pumilus, 
  with 
  the 
  doubtful 
  syno- 
  

   nym, 
  'obesus? 
  var. 
  S.,' 
  given 
  on 
  the 
  authority 
  of 
  Mr. 
  Say: 
  and 
  it 
  is 
  described 
  as 
  Elater 
  (Agriotes) 
  

   obesus 
  in 
  the 
  'Treatise 
  on 
  Insects 
  Injurious 
  to 
  Vegetation,' 
  in 
  which 
  the 
  specific 
  name 
  was 
  adopted 
  in 
  

   deference 
  to 
  Mr. 
  Say, 
  although 
  the 
  writer 
  was 
  previously 
  aware 
  that 
  the 
  insect 
  did 
  not 
  accord 
  with 
  

   Mr. 
  Say's 
  description 
  of 
  the 
  obesus." 
  

  

  The 
  following 
  specres 
  of 
  this 
  family 
  are 
  unknown 
  to 
  me; 
  those 
  described 
  from 
  Russian 
  

  

  