Raymond. — Correlation of the Ordovician Strata. 



PLATE 7. 



Fig. 1. Basal conglomerate of the Obolus sandstone at Packerort, Russia. 



Fig. 2. The "Glint" beneath Packerort light-house. Height, 80 feet. At 

 the bottom are seen the upper 8 feet of the Lower Cambrian, and 

 the contact with the Ordovician is indicated by the lower under- 

 cutting, which is at the base of the Obolus sandstone. Above 

 this sandstone may be seen the Dictyonema shales and then the 

 Glauconite sandstone, making the second undercutting. Above 

 this are the thin representatives of the Walchow and Kunda forma- 

 tions, and at the top, the overhanging Reval dolomite, the Dubo- 

 wiki being absent. 



