﻿LNVEBTEBBATES. 
  

  

  321 
  

  

  Genus 
  AYICULOPECTEN, 
  McCoy. 
  

  

  AVICULOPECTEN 
  VaRSOVIENSIS, 
  Sp. 
  UOV. 
  

  

  ^ 
  

  

  y 
  

  

  View 
  of 
  left 
  valve, 
  Natural 
  size. 
  

  

  Shell 
  large, 
  suborbicular, 
  hinge-line 
  rather 
  shorter 
  than 
  the 
  great- 
  

   est 
  breadth 
  of 
  the 
  valves 
  below. 
  Left 
  valve 
  nearly 
  flat, 
  posterior 
  

   ear 
  short, 
  and 
  forming 
  a 
  rather 
  acute 
  triangle, 
  which 
  is 
  clearly 
  de- 
  

   fined 
  from 
  the 
  posterior 
  margin 
  below. 
  

  

  Anterior 
  ear 
  nearly 
  twice 
  as 
  long 
  as 
  the 
  posterior, 
  not 
  so 
  dis- 
  

   tinctly 
  angular 
  in 
  outline, 
  the 
  outer 
  margin 
  curving 
  into 
  a 
  deep 
  in- 
  

   dentation 
  where 
  it 
  joins 
  the 
  lateral 
  border 
  of 
  the 
  shell. 
  Both 
  ears 
  

   show 
  traces 
  of 
  raised 
  lines 
  or 
  costae, 
  corresponding 
  to 
  those 
  on 
  the 
  

   body 
  of 
  the 
  shell, 
  and 
  on 
  the 
  anterior 
  ear, 
  faint 
  transverse 
  lines 
  of 
  

  

  growth 
  are 
  visible. 
  

   -21 
  

  

  