AVIS Eee 
(Magnified 500 diameters, except Fig. 1, which is 250.) 
Fras. 1-13. Sponge spicules. Croton Point. 
Fira. 14. Melosira granulata (Ehr.) Ralfs. Croton Point. 
ETGaelios Navicula Gruendeleri, A. S. Croton Point. 
Fria, 16. Diatoma sp? Plattsburg. 
Pie. 17. Diatom fragment from Croton Point. 
Fre. 18. * Navicula permagna, Edw. Croton Point. 
Fires. 19, 20. Sponge spicules. Kreischerville, S. I. 
Fiaes. 21, 22, 23, 24. From clay at Verplank. 
Fig. 25. Nitszchia granulata, Grun. Croton Point. 
Fria. 26. From clay at Croton Point. 
(To accompany paper by Heinrich Ries, entitled ‘““Mrcroscoric 
ORGANISMS IN THE CLays oF NEW YORK STATR,’’ pp. 165-169.) 
