LIST OF ILLUSTRATIONS. 

 Plates. 



I. — Photomicrographs of Ravenswood .Granodiorite. 

 II. — Distribution of the Ravenswood Granodiorite. 

 III. — Pyroxenite and Diorite. 

 IV. — Gneissoid Structure. 

 V. — McCoy Mine and Schist. 

 VI. — Geological Map of the Cortlaudt Series. 

 VII. — Changes in Coat Colors of Mice. 

 VIII. — Changes in Coat Colors of Mice. 

 IX. — Changes in Coat Colors of Mice. 



Text Figures. 



Page 



Poikilitic Relation of Biotite and Olivine in Peridotite 46 



Diagram of the Relations of the more important Types of the Cortlaudt 



Series 58 



Variation Diagram of the Cortlandt Series 59 



Relations of Spinel, Corundum and Magnetite in Emery 68 



Sillimanite Schist 71 



iv 



