PLATE A. 



EXPLANATION. 



Figure 1. Fine-grained gray syenite from East St. Cloud p. 145 



Magnified forty diameters. No. 1 of the systematic table. 

 Figure 2. The same between crossed Nicols. 

 Figure 3. Fine-grained gray syenite from Sauk Rapids p. 145 



Magnified forty diameters. No. 4 of the systematic table. 

 Figure 4. The same between crossed Nicols. 

 Figure 5. Red quartzose syenite from East St. Cloud p. 145 



Magnified forty diameters. No. 6 of the systematic table. 

 Figure 6. Gabbro from Rice Point, Duluth p. 147 



Magnified forty diameters. No. 2 of the systematic table. 



