RAYMOND: CORRELATION OF THE ORDOVICIAN STRATA. 275 



1. Green, white, and red sandstone with numerous frag- 

 ments of Obelus. Base not seen. 6 ft. = 6 ft. 

 Zones 1 and 2 represent the Paekerort formation. 



Section at Narwa. (Given by Schmidt (47) in the Guide for the 

 excursions of the St. Petersburg meeting of the International Geo- 

 logical Congress). 



Ci^. Echinosphaeritenkalk. Dolomite. 3.0 m. = 16.9 m. 



Cia- Upper Linsenschicht. ..3m. = 13.9 m. 



B,i,^. Vaginoceras limestone. Dolomite. 3.0 m. = 13. 6 m. 



Biiia- Lower Linsenschicht. .3 m. = 10.6 m. 



B„. Glauconite limestone. 3.3 m. = 10.3 m. 



B,. Glauconite sandstone with concretions of bituminous 



limestone with Dictyonema. .2 m. = 7. m. 



Am. Red Obolus sandstone showing cross-bedding. 2.6 m. = 6.8 m. 

 A,,. White fucoidal sandstone with sand concretions. 



4.2 m. = 4.2 m. 



Narwa. (Measured by the writer). Plate 6. 



8. Gray limestone, dolomitic, heavy-bedded, and with few 

 fossils at the top, thin-bedded and with numerous 

 Orthoceratites in the lower portion. 10 ft. = 36 ft. 10 in. 



7. Linsenschicht. 15 in. = 26 ft. 10 in. 



Zones 7 and 8 represent the Kunda formation. 



6. Hard thick-bedded gray limestone. 3 ft. = 25 ft. 7 in. 



5. Impure red limestone with numerous M. planilimhata. 

 Top layer a much weathered rusty one, full of holes. 



8 ft. = 22 ft. 7 in. 



4. Red clay-shale. 3 in. = 14 ft. 7 in. 



3. Green clayey sand. 4 in. = 14 ft. 4 in. 



Zones 3-6 represent the Walchow formation. 



2. Yellow, white and reddish massive and cross-bedded 

 sandstone with very numerous Obolus. At the base is 

 a layer of rounded, hard, sandstone pebbles, three, four, 

 and ten inches in diameter. Much pjTites in lower two 



or three feet, sometimes in hard layers. 11 ft. = 14 ft. 



Zone 2 represents the Paekerort formation. 

 1. Almost white, thin-bedded sandstone. Base not seen. 



9 3 ft. = 3 ft 



Zone 1 represents the Esthonia formation. 



