MARYLAND GEOLOGICAL SURVEY 231 



Occurrence. — Sunderland Formation. Near the headwaters of Is- 

 land Creek, Calvert County. 



Collections. — Maryland Geological Survey. 



Order POLYGONALES. 



Family POLYGONACEAE. 



Genus POLYGONUM Linne. 



Polygonum sp ? 



Description. — Numerous seeds of this genus occur in the various swamp 

 deposits, especially at Grace Point, but accurate specific identification is 

 not possible. 



Occurrence. — Talbot Formation. Grove Point, Cecil County; Grace 

 Point, Baltimore County. 



Collections. — Maryland Geological Survey. 



Order ROSALES. 

 Family PLATANACEAE. 



Genus PLATANUS Linne. 



Platanus aceroides Gcepp. 



Plates LXXIII, LXXIV. 



Platanus aceroides Gcepp, 1855, Zeitschr. Deutsch. Geol. Gesellsch., vol. iv, 

 p. 492; Tert. Fl. Schossnitz, p. 21, pi. ix, figs. 1-3. 



Description. — This widely represented species is hardly to be distin- 

 guished from the living P. occidentals L. and there would be no incon- 

 sistency in considering them as identical. 



The fragments figured on Plate LXXIII may be compared with those 

 figured by Heer from Spitzbergen, (Fl. Foss. Aret., vol. i, pi. xxxii, figs. 

 1, 2; ibid., vol. iv (Foss. Fl. Spitzb.), pi. xvii, figs. 1, 2 and xxxi, fig. 3), 

 Greenland (Fl. Foss, Arct, vol. vii, pi. xc) and Switzerland (Fl. Tert. 

 Helvet., vol. ii, pi. lxxxvii, figs. 3, 4 and lxxxviii, figs. 10, 11) and the 

 smaller leaves on Plate LXXIV with similar ones on the plate last cited. 

 Gaudin and Strozzi also figure a number of specimens from Italy (Mem. 



