TIMOTHY WILLIAM STANTON 
plants have been listed or described from the Kootanie of this 
neighborhood by Professors Newberry*tand Fontaine.* Theseshow 
a close connection with the not distant Canadian Kootanie, and 
more than half of them (21 out of 38) have also been identified 
from the Potomac. It is noteworthy, however, that no dico- 
tyledons have been found in the Kootanie, thus indicating that 
the higher horizons of the Potomac are possibly not represented 
there. Invertebrates are represented in the Great Falls area only 
by a few imperfect specimens of Unio. A higher bed which may 
belong to a later formation has yielded undescribed species of 
Neritina, Goniobasis, and Corbula (?). 
It is evident that the Kootanie and Potomac were laid 
down in distinct basins of fresh and brackish waters and that the 
floras prove that they are in part homotaxial equivalents. 
The Shasta group.— This general name was given by Gabb 
and Whitney to all the Lower Cretaceous rocks of California. 
Incisss DiC Ao Whites and Dr TG: i Becker. mamiedmino 
subdivisions of the Shasta, the Knoxville and the Horsetown beds, 
that have since been generally recognized. Detailed sections 
have been described by Turner,‘ Diller5 and the present writer ° 
who has recently reviewed the geology of the Knoxville beds 
and described their fauna. 
The Shasta is a marine formation distributed along the western 
side of the Sacramento valley and in the coast ranges of Califor- 
nia, Oregon, and Washington. The lower divisions have been 
recognized as far north as latitude 35°. 
“Dark clay shales greatly predominate over all other kinds 
of rocks in the Knoxville beds, but there is also considerable 
sandstone, usually in thin beds. In some places the lower part 
of the formation consists of alternations of shale and sandstone, 
t Am. Jour. Sci., 3d ser., Vol. XLI, 1891, pp. 191-201. 
2 Proc. U.S. Nat. Museum, Vol. XV, 1892, pp. 487-495. 
3 Bull. U. S. Geol. Surv., Nos. 15 and Io. 
4 Bull. Geol. Soc. Am., Vol. II, 1891, pp. 303-314. 
5Am. Jour. Sci., 3d ser., Vol. XL, 1890, pp. 476-478. Bull. Geol. Soc. Am., 
Vol. IV, 1893, pp. 205-224. Idem, Vol. V, pp. 435-464. 
6 Bull. U. S. Geol. Surv., No. 133, 1896. 
