276 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
ASSERIEN. (Zones 16 to 13 are well shown in the quarries and along 
the railroad about two miles south of the cement plant at Asserien. 
Zones 13 to 1 are well exposed at and below the large quarry at the 
edge of the cliff about a mile west of the plant. Measured by Dr. 
Twenhofel and the writer). 
16. Fine-grained magnesian limestone in layers one to threé 
inches thick. Very few fossils. 6 ft..=| 764. Lim 
15. Thick-bedded, fine-grained compact magnesian lime- 
stone with an abundance of Orthoceratites in the lower 
three feet. Some layers are porous and show open moulds 
of fossils. 8 ft. = 70 ft. 1 in. 
Zones 15 and 16 belong to the Reval formation. 
14. Thick- and thin-bedded gray limestone without much 
shale. Echinosphaerites especially abundant in the 
lower part. 7 ft. 6 in, = 62%t. 1 in, 
13. Light gray, rather thick-bedded limestone without 
shale, but becoming soft and shaly on weathering. This 
zone contains more or Jess “linsen” throughout, but 
they are especially abundant in the lower three feet. 
8 ft. = 54 ft. 7 in. 
Zones 13 and 14 make up the Dubowiki formation. 
12. Thick- and thin-bedded gray limestone which becomes 
soft and shaly on weathering. Many Vaginoceras 
present. 14ft. 8in. = 46 ft. 7 in. 
11. Lower “Linsenschicht.” 9 in. = 3P4te/11 ip. 
Zones 11 and 12 represent the Kunda formation. 
10. Thick-bedded gray limestone. 3 ft. 6 in. = 32 ft. 2 in. 
9. Thin-bedded limestone and shale. 6in. = 27 ft. 8 in. 
8. Thick-bedded, hard, reddish limestone with glauconite. 
3 ft. 6in. = 27 ft. 2 in. 
7. Clay and limestone. 8 in. = 23 ft. 8 in. 
6. Green clay and sandstone. 6 ft. 3in. = 23 ft. Oin. 
Zones 6 to 10 form the Walchow formation. 
5. Thin-bedded, soft, yellowish clay-shale. 4 ft. = 16 ft. 9 in. 
4. Red and yellow limonite. 3 in. = 12 ft. 9 in. 
3. Thin-bedded black shale with thin layers of sandstone 
in the lower half. 7 ft: =[12 £626 in. 
2. Light yellow and red cross-bedded sandstone, with 
lenses of thin, black shale in layers one fourth to one inch 
in thickness and with black deposits on the bedding 
planes. 3ft.3in. = 5 ft. 6 in. 
