J. Penny

STUDIES ON THE CONIFERS OF THE MAGOTHY FLORA

J. Penny, 1947 .

Plant microfossils and age of nonmarine Cretaceous sediments of Maryland and Delaware

J. J. Groot, J. Penny, 1960 .

An Early Middle Eocene flora from the yellowstone—Absaroka volcanic Province, Northwestern wind river basin, Wyoming: H.D. MacGinitie, 1974. University of California Press, Berkeley, 103 pp., 45 plates, US $5.75

J. Penny, 1975 .

Common Trees of Puerto Rico and the Virgin Islands.

F. Wadsworth, Elbert L. Little, Frank H. Wadsworth, 1965 .