﻿248 
  Lahee 
  — 
  New 
  Fossiliferous 
  Horizon 
  and 
  Underlying 
  

  

  Embedded 
  in 
  the 
  sandstone, 
  sometimes 
  partly 
  in 
  a 
  fossil 
  and 
  

   partly 
  outside, 
  are 
  occasional 
  large 
  cubes 
  of 
  pyrite 
  (up 
  to 
  1/4" 
  

   across). 
  Most 
  of 
  the 
  fossils 
  are 
  external 
  impressions, 
  although 
  

   a 
  few 
  internal 
  ones 
  have 
  been 
  found. 
  All 
  of 
  them 
  are 
  slightly 
  

   distorted. 
  (See 
  tigs. 
  7 
  to 
  9.) 
  There 
  is 
  not 
  a 
  vestige 
  of 
  the 
  

   original 
  shell 
  substance 
  left. 
  

  

  "While 
  the 
  characters 
  of 
  the 
  impressions 
  indicate 
  eight 
  or 
  

   nine 
  species, 
  none 
  of 
  the 
  fossils 
  is 
  perfect 
  enough 
  actually 
  to 
  

   determine 
  its 
  species. 
  With 
  the 
  assistance 
  of 
  Professor 
  Shimer, 
  

   to 
  whom 
  we 
  are 
  glad 
  to 
  express 
  our 
  thanks, 
  we 
  made 
  an 
  

   attempt 
  to 
  name 
  some 
  of 
  the 
  genera. 
  These 
  are 
  described 
  

   below 
  : 
  

  

  Fig. 
  7. 
  

  

  Fig. 
  7. 
  Stropheodonta 
  sp. 
  

  

  (1) 
  Stropheodonta 
  sp.? 
  (fig. 
  7) 
  : 
  Only 
  a 
  part 
  of 
  one 
  valve 
  was 
  

   found, 
  including 
  about 
  18 
  mm 
  of 
  the 
  hinge-line. 
  The 
  impres- 
  

   sion 
  is 
  nearly 
  flat. 
  Its 
  original 
  size 
  must 
  have 
  been 
  at 
  least 
  

   36 
  mra 
  by 
  33 
  mm 
  . 
  It 
  is 
  marked 
  by 
  line 
  radial 
  striae, 
  all 
  of 
  equal 
  

   height, 
  of 
  which 
  180 
  or 
  200 
  must 
  have 
  reached 
  the 
  outer 
  

   margin 
  of 
  the 
  shell 
  when 
  entire. 
  Few 
  run 
  the 
  whole 
  length. 
  

   These 
  striae 
  are 
  crossed 
  by 
  still 
  finer 
  concentric 
  wrinkles, 
  or 
  

   growth 
  lines, 
  which, 
  however, 
  are 
  not 
  well 
  preserved. 
  The 
  

   hinge-line 
  is 
  straight 
  and 
  has 
  on 
  it 
  indistinct 
  vertical 
  ridges. 
  

   In 
  general 
  aspect 
  this 
  specimen 
  is 
  like 
  S. 
  perplana. 
  

  

  (2) 
  Chonetes 
  sp.? 
  (fig. 
  8, 
  actual 
  size 
  shown 
  by 
  cross) 
  : 
  We 
  

   have 
  several 
  incomplete 
  specimens. 
  The 
  shell 
  is 
  about 
  20 
  mm 
  

   wide 
  and 
  12 
  mm 
  long. 
  It 
  is 
  nearly 
  flat, 
  slightly 
  convex. 
  Its 
  

   surface 
  is 
  marked 
  by 
  fine, 
  almost 
  straight, 
  equal, 
  radial 
  striae, 
  

   about 
  100 
  in 
  number. 
  They 
  are 
  crossed 
  by 
  three 
  or 
  four 
  low, 
  

   indistinct 
  concentric 
  folds. 
  The 
  hinge-line 
  is 
  straight 
  and 
  

   forms 
  the 
  greatest 
  diameter 
  of 
  the 
  shell. 
  Since 
  the 
  hinge 
  area 
  

  

  