S14 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.41. 



mentary specimens, is distinguishable with difficulty from its conge- 

 ners. It is especially close to Cladojphlehis albertsii and Clado])hlebis 

 ungeri. It is recorded from the uppermost Jurassic and lowermost 

 Cretaceous in Portugal, from the Neocomian of Japan, and from 

 the Wealden of England, Germany, and Austria. In America it 

 has been reported from the Shasta through the Horsetown and in 

 the base of the Chico formation on the Pacific coast, and from the 

 Kootenai formation of Montana and British Columbia. 



It is well scattered and abundant in the Potomac group, occurring 

 in all three of the formations, but represented for the most part by 

 incomplete specimens showing slight variations, which were made 

 the basis for many species of Professor Fontaine. Material from 

 the Patapsco formation of Maryland shows indistinct oval sori in 

 a single row on either side of the midvein. These are of the 

 type found associated with a number of other American species of 

 CladojiMebis. 



Professor Zeiller ^ has recently reported fertile fronds of Pecopteris 

 hrowniana, or of a very similar species, from the Wealden of Peru. 

 These are not figured, but are described as having biseriate, oval, 

 annulate sporangia as in the modern family Schizaeacese and very like 

 those of the Jurassic genus Klukia of Kaciborski, thus apparently 

 somewhat different from those of the American representatives of 

 the present species. Fragments from the Neocomian of Japan, 

 showing oval sori, are referred to this species by Yokoyama.^ 



Occurrence. — Patuxent formation: Fredericksburg, Dutch Gap, 

 Alum Rock, Telegraph Station (Lorton), Potomac Run, Virginia; 

 New Reservoir, Ivy City, District of Columbia; Broad Creek (?), Mary- 

 land. Aeundel formation : Arlington, Hanover, Howard Brown 

 Estate, Maryland. Patapsco formation : Brooke and vicinity, Chin- 

 kapin Hollow, Virginia; Federal Hill (Baltimore), Vinegar Hill, 

 Maryland. 



Collections. — United States National Museum, Johns Hopkins 

 University, Goucher College. 



CLADOPHLEBIS CONSTRICTA Fontaine, emended. 



Cladophlebis constricta Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, p. 68, 

 pi. 2, fig. 11; pi. 3, fig. 2; pi. 6, figs. 5,6, 8-14; pi. 21, figs. 9, 13; pi. 169, fig. 2.— 

 Fontaine, in Ward, Monogr. U. S. Geol. Surv., vol. 48, 1906, pp. 280, 297, 

 504, 528, 547, pi. 77, fig. 26.— Penhallow, Summ. Geol. Surv. Can., 1904 

 (1905), p. 9.— Knowlton, Smiths. Misc. Coll., vol. 4, pt. 1, 1907, p. 109. 



Cladophlebis latifolia Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, p. 69, 

 pi. 3, fig. 1; pi. 6, fig. 4. 



Cladophlebis virginiensis Fontaine, in Ward, Monogr. U. S. Geol. Surv., vol. 48, 

 1906, p. 512, pi. Ill, fig. 7. 



1 Zeiller, Comptes Rendus, vol. 150, 1910, p. 148S. 



2 Yokoyama, Journ. Coll. Sci. Japan, vol. 7, 1895, p. 220. 



