222 SYSTEMATIC PALEONTOLOGY 
to the Maryland specimen and to those figured by Knowlton. It is pos- 
sible that Fig. 4, Plate LXX, may belong to the same species. 
Occurrence-—SUNDERLAND Formation. Near the headwaters of Is- 
land Creek, Calvert County. 
Collections——Maryland Geological Survey. 
Hicoria sp. ? 
Plate LXX, Fig. 4. 
Description.—This fragment is too imperfect for anything more than 
generic determination. It is apparently the terminal leaflet of a Hickory. 
Occurrence——SUNDERLAND ForMATIoN. Point of Rocks, Calvert 
County. 
Collections.—Maryland Geological Survey. 
Hicoria sp. ? 
Description.—A small hickory nut, destitute of the outer husk, and 
considerably flattened, was found at Drum Point, but it was too distorted 
and imperfectly preserved for accurate or satisfactory specific determina- 
tion. 
Occurrence.—Tatpot Formation. Drum Point, Calvert County. 
Collections—Maryland Geological Survey. 
Genus PTEROCARYA Kunth, 
PTEROCARYA DENTICULATA (Web.) Heer. 
Plate LXXII, Figs. 6-10. 
Pterocarya denticulata Heer, 1859, Fl. Tert. Helvet., vol. iii, p. 94, Pl 
exxxi, figs. 5-7. 
Juglans denticulata Web., 1852, Paleontogr., vol. ii, p. 211, pl. xxiii, fis. 10. 
(Not J. denticulata Heer, 1869, Fl. Foss. Arct., vol. ii, Abth. iv, p- 48% 
pl. lvi, figs. 6-9.) 
Description.—These leaves are apparently identical with those figured 
by Ettingshausen under the above name (Foss. Fl. Bilin, pl. liii, figs 
11-15), although they might ath propriety be referred to the genus 
_ Hicoria, as they are closely related to H. pecan (Marsh.) Britton, or © 
_ H. minima (Marsh.) Britt ny trees of which bear leaflets that are 
