﻿The 
  Fauna 
  or 
  the 
  Niagara 
  G-eoup. 
  189 
  

  

  as 
  also 
  in 
  the 
  lateral 
  lobes. 
  Surface 
  marked 
  by 
  small 
  scattered 
  

   pustules, 
  most 
  distinct 
  on 
  the 
  cheeks 
  and 
  segments 
  of 
  the 
  

   axial 
  lobe. 
  

  

  Length 
  of 
  an 
  ordinary 
  specimen 
  17 
  mm. 
  ;. 
  greatest 
  width 
  of 
  

   thorax 
  a 
  little 
  more 
  than 
  8 
  mm. 
  ; 
  length 
  of 
  head, 
  6 
  mm. 
  • 
  

   length 
  of 
  pygidium 
  2 
  mm. 
  

  

  This 
  species 
  differs 
  from 
  all 
  others 
  described, 
  in 
  the 
  elongate 
  

   form 
  of 
  the 
  head 
  and 
  in 
  the 
  proportions 
  of 
  the 
  body. 
  

  

  ILLiENUS 
  Dolman. 
  

   Ill^enus 
  armatus 
  ? 
  

  

  Plate 
  32, 
  Figs. 
  19, 
  20. 
  

  

  Elcenus 
  armatus 
  Hall. 
  20th 
  Rept. 
  St. 
  Cab. 
  Nat. 
  Hist., 
  p. 
  320, 
  pi. 
  22, 
  figs. 
  1-3. 
  

  

  1867. 
  Rev. 
  Edit., 
  pp. 
  418, 
  433. 
  [1870.] 
  

   lllcenus 
  Barriensis 
  [Murch.] 
  Hall. 
  Trans. 
  Alb. 
  Inst., 
  vol. 
  iv, 
  p. 
  227. 
  Abstract, 
  

  

  p. 
  33; 
  May, 
  1863. 
  

  

  The 
  specimens 
  of 
  Ill^enus 
  occurring 
  in 
  this 
  locality 
  are 
  all 
  

   fragmentary, 
  and 
  so 
  imperfect 
  that 
  no 
  satisfactory 
  identifica- 
  

   tion 
  can 
  be 
  made. 
  The 
  form 
  of 
  the 
  pygidium 
  is 
  like 
  I. 
  

   armatus. 
  The 
  head 
  is 
  more 
  extended 
  in 
  front 
  than 
  in 
  that 
  

   species 
  from 
  Wisconsin, 
  but 
  this 
  may 
  be 
  due 
  in 
  some 
  degree 
  

   to 
  the 
  compression 
  which 
  has 
  flattened 
  the 
  specimens. 
  One 
  

   specimen 
  retaining 
  the 
  movable 
  cheek, 
  with 
  its 
  posterior 
  ex- 
  

   tension, 
  has 
  been 
  observed, 
  leaving 
  little 
  doubt 
  as 
  to 
  the 
  ident- 
  

   ity 
  of 
  the 
  species. 
  

  

  CERAURUS 
  Green. 
  

  

  Cheirurus 
  Bey 
  rich. 
  

  

  Ceraurtjs 
  (Cheirurus) 
  Niagarensis. 
  

  

  Plate 
  32, 
  Fig. 
  16. 
  

  

  Compare 
  Cheirurus 
  insignis 
  Beyrich. 
  Ub. 
  Bohm. 
  Tril., 
  p. 
  12, 
  fig. 
  1. 
  

  

  Compare 
  Cheirurus 
  insignis 
  Baerande. 
  Syst. 
  Sil. 
  Cent. 
  Boheme, 
  p. 
  782, 
  pi. 
  41. 
  

  

  Compare 
  Cheirurus 
  insignis 
  Cokda. 
  Proql., 
  p 
  133, 
  pi. 
  vi, 
  fig. 
  70. 
  

  

  Ceraurus 
  insignis 
  Hall. 
  Pal. 
  N. 
  Y., 
  vol. 
  ii, 
  pp. 
  300, 
  306, 
  pi. 
  67, 
  figs. 
  9, 
  10. 
  1862. 
  

  

  Ceraurus 
  insignis 
  Hall 
  . 
  20th 
  Rep. 
  St. 
  Cab. 
  Nat. 
  Hist., 
  p. 
  335. 
  1867. 
  

  

  Ceraurus 
  Niagarensis 
  Hall. 
  20th 
  Rep. 
  St. 
  Cab. 
  Nat. 
  Hist., 
  Rev, 
  Edit., 
  p. 
  427, 
  

   pi. 
  21, 
  figs. 
  10, 
  11. 
  [1870.] 
  

  

  Sphcerexochus 
  Romingeri 
  ? 
  Hall. 
  Doc. 
  Edit. 
  28th 
  Rep. 
  St. 
  Mus. 
  Nat. 
  -Hist. 
  Ex- 
  

   planation 
  of 
  pi. 
  32, 
  fig. 
  16. 
  (Erroneous 
  reference.) 
  

  

  