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. 



Hicoeia 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 Kocks, Calvert 

 County. 



Collections. — Maryland Geological Survey. 



HlCORIA 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. — Talbot 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, pi. 



cxxxi, figs. 5-7. 

 Juglans denticulata Web., 1852, Palaeontogr., vol. ii, p. 211, pi. xxiii, fig. 10. 



(Not J. denticulata Heer, 1869, Fl. Foss. Arct., vol. ii, Abth. iv, p. 483, 



pi. lvi, figs. 6-9.) 



Description. — These leaves are apparently identical with those figured 

 by Ettingshausen under the above name (Foss. Fl. Bilin, pi. liii, figs. 

 11-15), although they might with propriety be referred to the genus 

 Hicoria, as they are closely related to II. pecan (Marsh.) Britton, or to 

 H. minima (Marsh.) Britton, many trees of which bear leaflets that are 



