Maryland Geological Survey 249 



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



1889, p. 74 (pars), pi. vii, figs. 3, 4 (non fig, 5 which is referred to 



C. Browniana) . 

 Thinnfeldia variabilis Fontaine, 1894, in Diller and Stanton, Bull. Geol. 



Soc. Am., vol. V, p. 450. 

 Thinnfeldia variabilis Fontaine, 1896, in Stanton, Bull. U. S. Geol. Surv., 



No. 133, p. 15. 

 Thinnfeldia montanensis Fontaine, 1898, in Weed and Pirsson, 18th Ann. 



Rept. U. S. Geol. Surv., 1896-97, pt. iii, p. 481. 

 CladophleMs acuta angustifoUa Fontaine, 1906, in Ward, Mon. U. S. Geol. 



Surv., vol. xlviii, 1905, p. 539, pi. cxiv, fig. 5. 

 CladophleMs falcata montanensis Fontaine, 1906, in Ward, Mon. U. S. Geol. 



Surv., vol. xlviii, 1905, p. 291, pi. Ixxi, figs. 14-20. 

 CladophleMs falcata Fontaine, 1906, in Ward, Ibid., vol. xlviii, 1905, pp. 



227, 280, 511, 548, pi. Ixv, figs. 12-14; pi. cxi, fig. 6. 

 Cladophlebis acuta Fontaine, 1906, in Ward, Ibid., vol. xlviii, 1905, p. 538, 



pi. cxiv, figs. 3, 4. 

 CladophleMs falcata Knowlton, 1908, in Diller, Bull. Geol. Soc. Am., vol. 



xix, p. 386. 

 CladophleMs virginiensis Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 320. 



Description. — Frond large, bi- or tripinnate. Eachis stout and rigid. 

 Ultimate pinnas long, rather remote, alternate to subopposite. l^nnules 

 ovate to lanceolate and subfalcate in outline, sometimes obtusely pointed, 

 mostly separate to the base, attached by their whole base which is more 

 or less widened. Venation of the type usual in this genus. Margins 

 usually entire, sometimes crenulate to subdentate, becoming entire distad. 

 Texture coriaceous. The degree of separateness of the pinnules, as well 

 as their relative length and breadth and their more or less falcate form, 

 are characters dependent upon the age of the frond or the position of 

 the pinnules on the frond, long, narrow, almost straight proximal pin- 

 nules passing gradually into more or less short, broad, and falcate distal 

 pinnules. 



This species is not very different from the widespread type of Clado- 

 phlebis, commonly referred to the species Albertsii of Brongniart. It ex- 

 hibits considerable variation from specimen to specimen, but these varia- 

 tions show so many gradations and are so readily explained when the 

 position of the various fossil fragments upon the frond is taken into 

 consideration that any segregation of them is entirely unwarranted. In 

 general, the pinnules are larger and relatively much wider than in 

 CladophleMs Albertsii. 



