﻿600 
  NEW 
  YOEK 
  STATE 
  I^^JSEUM 
  

  

  (Magnified 
  500 
  diameters, 
  except 
  Fig. 
  1, 
  which 
  is 
  enlarged 
  250 
  

  

  •diameters) 
  

  

  Fig. 
  1-13 
  Sponge 
  spicules. 
  Croton 
  point 
  

   Fig. 
  14 
  Melosira 
  granulata 
  (Ehr.) 
  Ralfs. 
  Croton 
  point 
  

   Fig. 
  15 
  Navicula 
  Gruendeleri 
  A. 
  S. 
  Croton 
  point 
  

   Fig. 
  16 
  Diatoma 
  sp? 
  Plattsbnrg 
  

   Fig. 
  17 
  Diatom 
  fragment 
  from 
  Croton 
  point 
  

   Fig. 
  18 
  Navicula 
  permagna 
  Edw. 
  Croton 
  point 
  

   Fig. 
  19, 
  20 
  Sponge 
  spicules. 
  Kreischerville, 
  S. 
  I. 
  

   Fig. 
  21-24 
  From 
  clay 
  at 
  Yerplank 
  

   * 
  Fig. 
  25 
  Nitszchia 
  granulata 
  Grun. 
  Croton 
  point 
  

   Fig. 
  26 
  From 
  clay 
  at 
  Croton 
  point 
  

  

  I 
  

  

  