﻿GEOL. 
  SOC. 
  AM., 
  MEMOIR 
  76 
  

  

  PALMER, 
  PL. 
  22 
  

  

  OPALIA, 
  BARLEEIA, 
  BITTIUM, 
  EPITONIUM. 
  ALVANIA, 
  DIALA, 
  AND 
  TURBONILLA 
  

  

  