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THE CRETACEOUS RIM OF THE BLACK HILLS.

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sil plants were found and a small collection made. They bore no resemblance whatever to the flora of the Dakota Group, but consisted chiefly of ferns with a few coniferous twigs and possibly cycadean remains. In short the flora, so far as I could judge, was rather that of the Lower Cretaceous.

Fig. 3.Section across the divide between Red Valley and Minnekahta Creek.

1.	Red Beds.	12.	A, Cycad Bed.B, Fossil Forest.
2-7.	Jurassic.	13.	Equivalent of Quarry Sandstone in Section No. II.
9.	Plant Bed.

The entire section, from the Red Beds at the bottom of the cañon to the summit of the crest forming the divide, was carefully measured, the position of the fossil forest bed, the cycad bed, and the plant bed, fixed as nearly as the circumstances would permit, and all the variations in the nature of the strata indicated. The section, as determined on the spot, is as follows:

Section No. I.
Dakota of Newton.275 Feet.
13.	Massive pinkish sandstone approaching a quartzite locally	75 feet
12.	Grayish white sandstone with silicified wood and cycads	30 feet
11.	Pinkish and yellowish soft sandstone	75 feet
10.	Clays with indications of coal	20 feet
9.	Soft pink and gray sandstone with ferns and other plants	25 feet
8.	Reddish, pinkish, and yellowish brown massive cross-bedded sandstone	50 feet
Jurassic.220 Feet.
7.	Olive gray clay and sandstone shales	50 feet
6.	Light red soft sandstone	60 feet
5.	Olive gray clays and gray sandstone shales	40 feet
4.	Olive drab clay	20 feet
3.	Yellow sandstone shales	20 feet
2.	Olive drab clay	30 feet
Red Beds (Trias).
1.	Red marls, conformably exposed at bottom of cañon	20 feet

This section may be represented diagrammatically in Fig. 3.