﻿THE 
  TERTIARY 
  FORMATIONS 
  OF 
  VIRGINIA. 
  341 
  

  

  striae, 
  very 
  fine 
  near 
  the 
  umbones, 
  but 
  much 
  coarser 
  near 
  the 
  margin 
  ; 
  

   beaks 
  rather 
  elevated 
  ; 
  lunule 
  very 
  indistinct 
  ; 
  teeth 
  elevated 
  and 
  straight, 
  

   the 
  two 
  posterior 
  ones 
  of 
  the 
  left 
  valve 
  small, 
  much 
  compressed, 
  ap- 
  

   proximate, 
  and 
  nearly 
  parallel 
  ; 
  the 
  anterior 
  tooth 
  large 
  and 
  grooved 
  

   by 
  a 
  deep 
  canal 
  ; 
  cavity 
  of 
  shell 
  deep 
  ; 
  margin 
  entire 
  ; 
  posterior 
  margin 
  

   straight, 
  and 
  separated 
  from 
  the 
  muscular 
  impression 
  by 
  a 
  fold 
  or 
  groove. 
  

   Length, 
  one 
  inch 
  and 
  one-tenth 
  ; 
  height 
  eighty-five 
  hundredths 
  of 
  an 
  

   inch. 
  

  

  Locality, 
  Coggins 
  Point, 
  in 
  the 
  Eocene 
  green 
  sand. 
  

  

  VOL. 
  V. 
  4 
  L 
  

  

  