PLATE VI. 



FIG. i. MARCASITE PKBBLE FROM THE LAKK SHORE, 



FIG. 2. MARCASITE PEBBLES; CRYSTAL PLANES STILL EVIDENT IN TWO LOWER SPECIMENS: 



TWO UPPER SHOW AC1CULAR CRYSTALS BORDERING CORE OK GRANULAR 



MARCASITE, THUS FORMING NODULES. 





