Lesquereux.] 200 [March. 



8. Hard coarse limestone, with great abundance of the same 

 fossils as the upper one, . . . . . . .10 



9. Cherty limestone, mostly hard silex, .... 6 



10. Coarse sandstone with plants, Stigmaria, Sigillaria, Le- 

 pidodendron, &c.,* . 60 



11. Coarse limestone, lower Archimedes bed or middle bed? 30 



12. Coarse and soft brown sandstone with a great number 



of fossil shells (Knob sandstone ?) ..... 100 



13. Hard black limestones with fossils, .... 40 



14. Black and yellow shales with carbonate of iron (Devo- 

 nian?) 40 



The second section is that of the Millstone Grit, and is taken from 

 the base to the top of the Horsehead Mountain, a part of the Boston 

 Mountain in Johnson County. It is, 



FEET. INCHES. 



1. Calcareous shales and argillous sandstone, containing a 

 quantity of fossil shells. The top of the hill is covered, 

 and apparently has a stratum of conglomerate ; at least 

 loose pieces of conglomerate are found above the exposed 

 fossiliferous shaly sandstone. From top of hill down, . 30 



2. Compact and shaly sandstones in alternating beds, . . 120 



3. Massive, coarse, gritty sandstone, ..... 80 



4. Shaly sandstone, sometimes in banks, covered with ver- 

 micular impressions, and cut by hard bauds (ferruginous 

 shales), 120 



5. Coarse, gritty sandstone, with conglomerate at the upper 

 part. The pebbles are small, not larger than a bean, . 20 



6. Hard, compact, gritty sandstone in banks, alternating 

 with shales and shaly sandstone, ..... 520 



7. Red, yellow, and soft ferruginous shales and shaly sand- 

 stone, 150 



8. Gray, hard, micaceous shales, mixed with pebbles of car- 

 bonate of iron, and having fossil plants especially near the 

 base, from 10 to TO 



(These shales at Horsehead have at some banks only six 

 feet, at others as high as seventy feet. They pass to sand- 

 stone at the upper part.) 



9. Black, soft, earthy shales, 1 



10. Coal, 10 inches to 1 6 



11. Fireclay, black, hard, full of stigmaria to. level of the 

 creeks. 



* In Illinois, the sandstone has the same plants, and is overlaid by one bed 

 only of the Archimedes limestone. In Indiana, where this sandstone is absent, it 

 is replaced by a thin bed of coal just under the upper Archimedes. 



