﻿GEOL. 
  SOC. 
  AM., 
  MEMOIR 
  76 
  

  

  PALMER, 
  PL. 
  17 
  

  

  DENTALIUM, 
  SOLARIELLA, 
  MARGARITES, 
  CALLIOSTOMA, 
  CIDARINA, 
  AND 
  ACMAEA 
  

  

  