RAYMOND: CORRELATION OF THE ORDOVICIAN STRATA. 273 
Big. Thin-bedded limestone with red and yellow spots. 
Very little glauconite. 1.8 m. = 3.45 m. 
Biz. Thick-bedded, red, yellow, violet, and gray-green 
limestone. 1.65 to 1.80 m. = 1.65 m. 
SECTION ON THE WatcHow. (Measured by the writer). 
The highest beds are exposed in the quarries at Dubowiki. Zones 
11 to 9 were measured near the steamboat landing at St. Michael 
Archangel, and the remainder of the section on the eastern bank of 
the Walchow opposite Iswos. 
11. Light gray to yellowish magnesian limestone in beds 
: one inch to one foot in thickness. Some layers are fine 
grained and dense, while others are porous, the fossils 
occurring as hollow moulds. Christiania oblonga com- 
mon and characteristic. Reval formation. 25 ft. = 112 ft.+ 
10. Soft gray limestone which breaks down readily to a 
sticky calcareous mud. Entire trilobites and other 
perfect fossils common. Echinosphaerites aurantium 
abundant. : 
Dubowiki formation. Base not exposed. 14 ft. = 87 ft.+ 
9. Concealed to river level. 23 ft. = 73 ft. 
(According to the thickness given by Lamansky the 
greater part of the concealed interval here would be filled 
by the “Orthoceras” limestone (Kunda formation)). 
8. Red and green limestone enclosing the “Lower Linsen- 
schicht.” 3 ft. = 50 ft. 
7. Thin-bedded limestone and shale, with 3 feet of rather 
solid limestone at the top. Byys (Bie of Lamansky). 
9 ft. = 47 ft. 
6. Thick-bedded gray limestone with shaly partings. 
(Bix) 10 ft. 6 in. = 38 ft. 
5. Thin-bedded, shaly limestone. (By,,). 5 ft. 6in. = 27 ft. 6 in. 
4. Heavy-bedded red limestone with abundant glauconite 
and echinoderm fragments. (By,.). 6. ft. i=/22 ft. 
3. Sandy shale. 1 ft. = 16 ft. 
) Zones 3-7, and the lower part of zone 8, below the 
Linsenschicht, belong to the Walchow formation. 
2.. Concealed. 3 ft. = 15 ft. 
1. White and gray sandstone to the river’s edge. Zones 1 
and 2 belong to the Packerort formation. 12 ft.= 12 ft. 
