)'7'> 



FLOKA OF OLDFK i'OTO.MAC FUILMATIU.X. o < b 



these forms, which were the eaHiost obtained fi'oin the formation, it is 

 of interest to see precisely what they were, so far as can he ascertained 

 without access to the specimens themselves, wlK)se whereabouts is now- 

 unknown, if, indeed, they were preserved at all. I therefore give the 

 list with the names used by Taylor, his figures, and Professor Fontaine's 

 identifications: 



Lyc-oixxliolitlu's ^ sp. Taylor: Trans. (Jeol. Sue. Pennsylvania. Vol. 1, Phila- 

 delphia, is:5."), p. :i'-'l, pi. xix, n<,'. •_'. Probably a cast or stem of Fniiclopxis r<nii(>sl.'<- 



slma Font. 



Lepidodendron sp. Taylor: ibid., p. ■.V22. li-:. 1. Splienolei)idiuni Sternberj,'- 



ianum (Dunk.) Fleer. 



Sphenopteris sp. Taylor: Ibid., fig. 'A. Seleropteris elliptica Font. 

 Pecopteris ? sp. Taylor: ibid., p. iiS. tig. 4. C'ladophlehis constrieta Font. 

 Thuites ? sp. Taylor: Ibid., tig. r,. Sphenolepidiuin dentiloliuin Font. 

 Sphenopteris sp. Taylor: ll)id.. tig. 6. C'ladophlehis constrieta Font. 



In May, 1891, I resumed the study of the Potomac formation, 

 assisted to a considerable extent by Mr. David White, and accompanied 

 on some of the excursions by Mr. Robert T. Hill, Prof. P. R. Uhler, and 

 others. On June 13 I discovered the important locality- for fossil plants 

 in Hosiers Bluff, above Fort Foote, and made the first small collection 

 from there. The exact locality is 200 yards below Notley Hall wharf, 

 on the Fort Foote reservation. The clays rise here about 60 feet above 

 the river and occupy in the highest place all but a few feet of cobble and 

 surface gravel. They are varied in color, largely variegated i-ed and 

 white, but often with more or less lenticular layers of blue, brown, and 

 darker. They are interstratified with sand, gravel, and ferruginous 

 shales. The plants were found about 30 feet above the water, in a thin 

 stratum of l:)luish clay, between two seams of coarse sand. 



On June 20 I made the following section of the exposure discovered 

 by me in 1885 near Aquia Creek, from which so many dicotyledonous 

 forms were subsequently collected, and which is designated by Professor 

 Fontaine in his monograph as "Bank near Brooke:" 



Section of the l>ank mar Brooke. 



Fofi. 



4. Fiiio-grained aiui Intniimted wliit,c. liluc, and bviff clays yioiding the los,sil plants and extending to the 



roots of tlie small trees, shrubs, and herbage covering the hill 1- 



3. White ferruginous sands, fre(|uenlly cross-bedded, with very little uiterstratitied clay, covered at the 



base, but traceable to near the bottom of the ravine 21 



2. Pack sand in gulch at bottom of ravine '- 



1. While clay .streaked with pink and red at bottom of gulch ■. 2 



Total exposure *^ 



