Maryland Geological Survey 247 



Heer described as Pecopteris arciica^ Pecopteris Andersoniana/ and 

 Pecopteris hyperboreaJ' Abroad the species described by Schenk * from 

 the German Weal den as Alethopteris cycadina is very close to the Ameri- 

 can species, as Fontaine has already pointed out. 



Cladophlebis constricfa exhibits considerable variation in the degree 

 of remoteness and outline of the pinnules, and may possibly include more 

 than one species, the fact that certain of these aberrant forms come from 

 the low horizon at Fredericksburg, while all of the other occurrences 

 are from Patapsco outcrops lends some credence to this suggestion. The 

 species has been reported by Penhallow from the Kootanie in Canada, 

 but this determination cannot be accepted with certainty. 



Occurrence. — Patuxent Formation. Fredericksburg, Virginia. Pa- 

 tapsco Formation. Hell Hole (?), Brooke, Deep Bottom, Virginia; 

 Federal Hill (Baltimore), Vinegar Hill, Ft. Foote (?), Maryland. 



Collection. — IJ. S. National Museum. 



Cladophlebis rotundata Fontaine 



CladophleMs rotundata Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 1889, 



p. 78, pi. XX, figs. '9, 10. 

 Cladophlebis brevipennis Fontaine, 1890, Mon. U. S. Geol. Surv., vol. xv, 



1889, p. 81, pi. xxxvi, fig. 1. 

 f CladophleMs rotundata Penhallow, 1905, Summary, Geol. Surv. Canada, 



for 1904, p. 9. 

 Cladophlebis rotundata Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., 



vol. xlviii, 1905, pp. 491, 510. 

 Cladophlebis rotundata Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 317. 



Description. — " Frond bipinnate or tripinnate, arborescent ( ?) ; prin- 

 cipal rachis stout, rounded, and prominent; pinnae short, with a strong 

 rigid rachis ; ultimate pinnse, from the lower part of the frond, with al- 

 ternate, 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 towards the summit with pinnules passing 

 through such forms as rotundate, subrhombic, and decurrent to entire 



^Heer, Fl. Foss. Arct, Band i, 1868, p. 80, pi. i, fig. 13; pi. xliii, fig. 5. 

 ' == Heer, Ibid., Band iii, Abth. ii, 1874, p. 41, pi. iii, fig. 7, b. 



* Heer, Ibid., Band i, 1868, p. 81, pi. xliv, fig. 4. 



* Schenk, Palaeont., Band xix, 1871, p. 218, pi. xxxi, fig. 2. 



