﻿NIAGARA 
  FALLS 
  AND 
  VICINITY 
  

  

  203 
  

  

  Whitfieldella 
  oblata 
  Hall 
  (Fig. 
  125). 
  Atrypa 
  oblata 
  Hall 
  

   (1852. 
  Pal. 
  N. 
  Y. 
  2:9, 
  pi. 
  4) 
  

  

  Distinguishing 
  characters. 
  Oblate 
  form, 
  nearly 
  as 
  broad 
  as 
  high; 
  

   broadest 
  anteriorly; 
  sloping 
  abruptly 
  to 
  the 
  beak; 
  small, 
  well 
  

  

  Fig. 
  125 
  Whitfieldella 
  oblata 
  

  

  defined 
  beak; 
  nearly 
  equally 
  conVex 
  valves; 
  central 
  groove 
  on 
  

   pedicle 
  valve 
  and 
  slight 
  elevation 
  on 
  brachial 
  valve 
  ; 
  surface 
  marked 
  

   only 
  by 
  lines 
  of 
  growth. 
  

  

  Found 
  in 
  the 
  upper 
  Medina 
  sandstone 
  at 
  Niagara. 
  Also 
  at 
  

   Lockport 
  (Hall). 
  

  

  Whitfieldella 
  intermedia 
  Hall 
  (Fig. 
  

   126). 
  Atrypa 
  intermedia 
  Hall 
  

   (1852. 
  Pal. 
  N. 
  Y. 
  2:77, 
  pi. 
  24) 
  

  

  Distinguishing 
  characters. 
  Obovate 
  ; 
  

   rapidly 
  expanding 
  to 
  front, 
  which 
  is 
  

   abruptly 
  rounded; 
  length 
  and 
  width 
  

   nearly 
  equal; 
  convex 
  near 
  beak, 
  flatter 
  

   toward 
  front; 
  slight 
  frontal 
  sinuosity; 
  

   faint 
  growth 
  lines. 
  

  

  -r^ 
  1 
  • 
  . 
  1 
  /--1 
  • 
  1 
  1 
  Fig. 
  126 
  Whitfieldella 
  Intermedia 
  

  

  round 
  m 
  the 
  Clinton 
  lenses 
  and 
  

   lowest 
  Clinton 
  shales 
  at 
  Niagara. 
  Also 
  in 
  the 
  upper 
  Clinton 
  lime- 
  

   stone 
  at 
  Lockport 
  (Hall). 
  

  

  Whitfieldella 
  cylindrica 
  Hall 
  (Fig. 
  127). 
  Atrypa 
  cylin- 
  

   dr 
  i 
  c 
  a 
  Hall 
  (1852. 
  Pal. 
  N. 
  Y. 
  2:76, 
  pi. 
  24) 
  

  

  Fig 
  127 
  Whitfieldella 
  cylindrica 
  

  

  Distinguishing 
  characters. 
  Elongate 
  cylindric; 
  strongly 
  convex; 
  

   nearly 
  as 
  wide 
  as 
  thick; 
  strongly 
  overarching 
  beak 
  of 
  pedicle 
  valve; 
  

  

  