318 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 41. 



part of the frond, with alternate, short, broadly ovate, very obtuse, round-lobed 

 pinnules, those of the upper part of the frond having the lowest pinnules distinct 

 and more or less round-lobed, and toward the summit with pinnules passing through 

 such forms as rotundate, subrhombic, and decurrent to entii^e and rounded, the latter 

 having the tips round-lobed and very obtuse ; nerves varying according to the position 

 and shape of the pinnules, those of the round-lobed pinnules and of the pinnte reduced 

 to pinnules flabellately diverging in each lobe, the branches being either forked or 

 simple. The nerves of the subrhombic pinnules have a midnerve, which sends off 

 alternately on each side forked or simple branches. All the nerves are very strongly 

 marked and stout. The leaf-substance is thick and leathery. 



The foregoing description was written for Cladophlebis rotundata, 

 but it requires no alteration to include the rare fragments which were 

 named Cladophlelis hrevipennis. as the material on which the two 

 were founded is identical; in fact, the description of the latter was 

 practically a paraphrase of the former. 



This species, while founded upon rather scant remains, is well 

 characterized by the strong venation and the breadth of the short 

 ovate pinnules. It may possibly represent Cladoplilehis constrida 

 Fontaine, as it closely resembles the form of the latter species which 

 Professor Fontaine named CladopTdelis latifolia. It has been recorded 

 by PenhaUow from Yukon Territory in Canada, but the identification 

 is very doubtful. 



Occurrence. — Patuxent formation: Fredericksburg, Dutch Gap, 

 Virginia. Patapsco formation: Mount Vernon, Cliinkapin Hollow, 

 Virginia. 



Collections.— Vnited States National Museum. 



CLADOPHLEBIS UNGERI (Dunker) Ward. 



Pecopteris ungeri Dunker, Monogr. Norddeutsch. Wealdenbildung, 1846, p. 6, 



pi. 9, fig. 10. 

 Pecopteris polymorpha Dunker, Monogr. Norddeutsch. Wealdenbildung, 1846, 



p. 6, pi. 7, fig. 5 (not Brongniart). 

 Pecopteris dunkeri Schimper, Pal. Veget., vol. 1, 1869, p. 539. 

 Pecopteris exiliformis Geyler, Palaeont., vol. 24, 1877, p. 226, pi. 30, fig. 1. 

 Aspidium dunkeri Fontaine, Monogr. U. S. Geol Sm'v., vol. 15, 1890, p. 101, 



pi. 22, figs. 9, 9a, 96; pi. 25, figs. 11, 12; pi. 26, figs. 2, 8, 9, 18; pi. 54, figs. 3, 9.— 



Fontaine, in Diller and Stanton, Bull. Geol. Soc. Amer., vol. 5, 1894, p. 



450.— Fontaine, in Stanton, Bull. 133, U. S. Geol. Surv., 1896, p. 15. 

 Cladophlebis dunkeri Seward, Wealden Flora, pt. 1, 1894, p. 100, pi. 7, fig. 3.— 



Fontaine, in Ward, Monogr. U. S. Geol. Surv., vol. 48, 1906, pp. 510, 538. 

 Pecopteris exilis Yokoyama, Journ. Coll. Sci. Japan, vol. 3, 1890, p. 35, pi. 1, 



figs. 8-10. 

 Aspidium parvifolium Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, p. 



100, pi. 21, fig. 6; pi. 24, fig. 8; pi. 25, fig. 10; pi. 26, figs. 1, 14, 16, 17. 

 Dryopteris parvifolia Knowlton, Bull. 92, U. S. Geol. Surv., 1898, p. 92. — 



Fontaine, in Ward, Monogr. U. S. Geol. Surv., vol. 48, 1906, p. 486 (not p. 



541, pi. 114, fig. 7). 

 Pecopteris geyleriana Nathorst, Denkschr. k. Akad. Wiss. Wien, vol. 57, 1890, p. 



48, pi. 4, figs. 2-6.— Yokoyama, Journ. Coll. Sci. Japan, vol. 7, 1895, p. 219, 



pi. 21, fig. 12; pi. 23, figs. 1, la; pi. 38, fig. 5. 



