﻿188 
  LAI. 
  1. 
  ONTOLOGY 
  OF 
  ILLINOIS. 
  

  

  P(ECILODDS 
  SPRIN'.I.I.I. 
  St. 
  J. 
  and 
  W. 
  

   PI. 
  VIII, 
  Fit. 
  1". 
  

  

  The 
  pr< 
  -■■nt 
  -pecies 
  is 
  made 
  known 
  from 
  pre- 
  

  

  ting 
  the 
  posterior 
  or 
  terminal 
  form 
  of 
  the 
  mandible. 
  The- 
  teeth 
  

   attain 
  medium 
  size, 
  strongly 
  arched 
  in 
  the 
  direction 
  of 
  inrollment. 
  

   Antero-lateral 
  border 
  slightly 
  oblique, 
  outward 
  and 
  forward, 
  to 
  the 
  

  

  era! 
  course 
  of 
  the 
  inner 
  margin, 
  relatively 
  short, 
  basal 
  bord 
  

   channeled; 
  postero-lateral 
  border 
  converges 
  toward- 
  outer 
  inrolled 
  

   margin 
  at 
  an 
  angle 
  of 
  50 
  more 
  or 
  less, 
  with 
  opposite 
  border, 
  basal 
  

   portion 
  unknown 
  ; 
  inner 
  margin 
  Btrongly 
  deflected 
  backward 
  from 
  

   tlic 
  very 
  obtuse 
  anterior 
  angle, 
  making 
  an 
  angle 
  at 
  the 
  base 
  of 
  the 
  

   anterior 
  lobe, 
  with 
  a 
  regular 
  concavity 
  in 
  the 
  region 
  of 
  the 
  median 
  

   depression, 
  as 
  also 
  in 
  passing 
  the 
  posterior 
  depression 
  into 
  the 
  

   acutely 
  rounded 
  posterior 
  extremity, 
  broadly 
  arched 
  round 
  tl 
  

   of 
  the 
  posterior 
  or 
  principal 
  lobe. 
  The 
  characteristic 
  contour 
  featui 
  

   strongly 
  marked 
  in 
  the 
  coronal 
  region 
  ; 
  anterior 
  lobe 
  rising 
  into 
  a 
  

   narrow 
  sharply 
  rounded 
  crest, 
  anterior 
  slope 
  slightly 
  concave 
  and 
  

   defined 
  by 
  a 
  narrow 
  rounded 
  fold 
  inbeveled 
  to 
  the 
  inferior 
  or 
  bat 
  

   birder; 
  median 
  depression 
  deeply 
  excavated 
  and 
  regularly 
  conca 
  

   transversely, 
  marked 
  by 
  a 
  few, 
  three 
  more 
  or 
  !. 
  38, 
  parallel 
  longitu- 
  

   dinal 
  folds; 
  posterior 
  ridge 
  more 
  broadly 
  arched 
  tram 
  . 
  prom- 
  

   inent, 
  abruptly 
  declining 
  into 
  the 
  deep 
  posterior 
  depression, 
  wind 
  

   bordered 
  by 
  the 
  Btrongly 
  apraised, 
  broad 
  alation. 
  Suit 
  ice, 
  aside 
  

   from 
  the 
  already 
  mentioned 
  longitudinal 
  folds 
  occupying 
  the 
  bottom 
  

   the 
  median 
  depression, 
  smooth, 
  and 
  minutely 
  and 
  densely 
  anno- 
  

   tate, 
  the 
  puncta 
  exhibitin 
  trans\ 
  ^position 
  in 
  

   lines 
  parallel 
  with 
  the 
  inner 
  margin. 
  Breadth 
  - 
  of 
  

   inner 
  margin 
  21 
  mm.; 
  Length 
  along 
  antero-lateral 
  border 
  6 
  mm., 
  

   or 
  a 
  trifle 
  less 
  than 
  half 
  the 
  longitudinal 
  diameter 
  aloi 
  rioi 
  

   lobe. 
  

  

  The 
  al 
  i 
  the 
  r. 
  - 
  of 
  which 
  \\« 
  n 
  

  

  by 
  Frank 
  spin 
  • 
  I. 
  i.. 
  in 
  whose 
  honor 
  the 
  Bpecifi< 
  

   given, 
  offers 
  resemblances 
  almost 
  equally 
  intimate 
  with 
  the 
  

  

  and 
  Cb< 
  Bter 
  form:: 
  

  

  the 
  Upper 
  Mississippi 
  region, 
  so 
  far 
  at 
  l< 
  may 
  l* 
  bj 
  

   tbi 
  m 
  of 
  tl 
  form 
  

  

  TL.' 
  extreme 
  obliquity 
  ox 
  rather 
  posl 
  1 
  inner 
  

  

  margin 
  in 
  front 
  of 
  the 
  anterior 
  lobe, 
  i 
  be 
  form 
  

  

  