Maryland Geological Survey 483 



various species generally referred to Cissites, in fact this Potomac species 

 was described as a new species in that genus by Saporta in his description 

 of the fossil plants of Portugal, although the name he used had already 

 been used two years earlier by Lesquereux for a different species. That it 

 is identical with the Potomac plant may be seen by a comparison of one 

 of Saporta's figures reproduced on pi. xci with the figures of the Federal 

 Hill plant on the same plate. 



Prof. Fontaine differentiated two species from Federal Hill, the more 

 common muUifidum and the very small and rather rare parvifolium, 

 the latter being simply small leaves of the former. The same author 

 described a third species from Potomac Run, Va. {Vitiphyllum crassi- 

 folium loc. cit., 1889, p. 308, pi. cl. figs. 9, 10), based on what he took 

 to be the middle lobe of a leaf of this species but which is so incomplete 

 as to be altogether worthless as evidence of the existence of this type in 

 Virginia in beds older than the Patapsco formation. Leaves of the same 

 general plan as Cissites parvifoUus are present in succeeding formations 

 where they attain a considerably larger size, thus some of the Earitan 

 forms which ISTewberry referred to Cissites formosiis Heer are very sug- 

 gestive of the Federal Hill plant. A closely allied species called by 

 Velenovsky Cissus vitifolia has also been described from the Cenomanian 

 of Bohemia. 



Occurrence. — Patapsco Foemation. Federal Hill (Baltimore), very 

 common, near Wellhams (?), Vinegar Hill (?), Maryland. 



Collections. — U. S. National Museum, Johns Hopkins University, 

 Goucher College, 



Order THYMELEALES 



Family LAURACEAE 



Genus SASSAFRAS Nees and Eberm 

 [Handb. Med. Pharm. Bot., Bd. ii, 1831, p. 418] 



This genus is characterized as follows by Schimper ' : " Folia plus 

 minus ovato-orbiculata, brevissime acuminata, vel triloba, triplinervia, 



^Schimp., Pal. Veget, t. ii, 1872, p. 834. 



