knowlton.] TERTIARY PLANTS OF NORTH AMERICA. 87 
DICKSONIA Presl. Pterid., p. 135, 1830. 
Dicksonia munda Dn. Trans. Roy. Soc. Canada, vol. iii, sec. iv, p. 11, 
pi. iii, f. 5, 5a, 1885 [1886J. 
Mill Creek series : Mill Creek. 
Dicksonia sp., Dn. Trans. Roy. Soc. Canada, vol. iii, sec. iv, p. 5, 1885 
[1886]. 
Kootanie : Martin Creek, British Columbia. 
DIOONITES Miquel. Tijdschr. v. Wis- en kat.'-Wetens., vol. iv 7 p. 
211 (7 of reprint), 1851. 
Dioonites borealis Dn. Trans. Roy. Soc. Canada, vol. i, sec. iv, p. 24, 
pi. iii, f. 37, 1882 [1883]. 
Lower Cretaceous 1 ?: Willow Creek, Northwest Territory. 
Kootanie : Martin Creek and Canmore, British Columbia. 
Dioonites Buchianus (Ett.) Born. Org. Reste d. Lettenkohlengr. 
Thuringens, p. 57, 1856; Font., Potomac FL, p. 182, pi. lxviii, f. 1 ; 
lxix, f. 1,3; lxx, f. 2,3; lxxi, f. 1; Ixxii, f. 1, 2; lxxiii, f. 1-3; lxxiv, 
f. 1-3, 1889. 
Pterophyllum Buchianum Ett. Fl. d. Wealdenb., p. 21, 1852. 
Potomac formation : James River, Trents Reach, Dutch Gap Canal, 
Kankeys, and near Telegraph Station, Virginia. 
Trinity division: Glenrose, Texas. 
Dioonites Buchianus angustifolius Font. Potomac Fl., p. 185, pi. 
lxvii, f. 6; lxviii, f. 4; lxxi, f. 2, 1889. 
Potomac formation : Dutch Gap, Kankeys, and Occoquan, Virginia. 
Trinity division : Glenrose, Texas. 
Horsetown beds: Shasta County, California. 
Dioonites Buchianus obtusifolius Font. Potomac Fl., p. 184, pi. 
clxviii, f. 3, 1889. 
Potomac formation: Dutch Gap Canal, Virginia. 
Dioonites Buchianus rarinervis Font. Proc. U. S. Nat. Mus., vol. xvi, 
p. 264, pi. xxxvi, f. 3, 4, 1893. 
Trinity division . Glenrose, Texas. 
Knoxville beds: Tehama County, California. 
Dioonites columbianus Dn. Trans. Roy. Soc. Canada, vol. x, sec. 
iv, p. 91, 1892 [1893]. 
Cycadeospermum (Dioonites) columbianus Dn. Geol. Surv. Canada, Rept. 
of Progress for 1872-73, Appen. i, p. 69, pi. i, f. 1-12, 1873. 
Lower Cretaceous: Skidegate Channel, Queen Charlotte Island. 
Dioonites Dunkerianus (Gopp.) Miq. Tijdschr. v. Wis en Nat.- 
Watens., vol. iv, p. 212, 1851 ; Font. Proc. U. S. Nat. Mus., vol. xvi, 
p. 265, pi. xxxvi, f. 12; xxxvii, f. 1, 1893. 
Trinity division: Glenrose, Texas. 
Horsetown beds : Shasta County, California. 
DIOSCOREA Plumier ex Linmeus. Gen., ed. i, p. 306, 1737. 
Dioscorea? cretacea Lx. Cret. Fl., p. 56, pi. xxviii, f. 10, 1874. 
Dakota group : Western Kansas. 
