NO. 1862. FOSSIL FERNS FROM THE POTOMAC QROVP— BERRY. 313 



Pecopteris cf. Browniana Nathorst, Denkschr. k. Akad. Wiss. Wien, vol. 57, 1890, 



p. 53, pi. 5, fig. 5. 

 Cladopklebis inaequiloba Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, p. 



80, pi. 25, fig. 8.— Fontaine, in Ward, Monogr. U. S. Geol. Surv., vol. 48, 



1906, p. 510. 

 Cladopklebis petiolata Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, p. 80, 



pi. 22, fig. 8. 

 Cladophlebis oblongifolia Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, 



p. 74 (part), pi. 7, fig. 5 (not figs. 3, 4 which are referred to Cladophlebis 



virginiensis Fontaine). 

 Cladophlebis crenata Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, p. 75, 



pi. 9, figs. 7-9; pi. 10, figs. 1, 2; pi. 13, figs. 1-3; pi. 19, fig. 7; pi. 20, fig. 6.— 



Fontaine, in Ward, Monogr. U. S. Geol. Surv., vol. 48, 1906, p. 547. 

 Cladophlebis alata Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, p. 77, pi. 



19, fig. 5. — Fontaine, in Ward, Monogr. U. S. Geol. Surv., vol. 48, 1906, pp. 



229, 480, 510, 544, 557, pi. 65, figs. 17-21. 

 Cladophlebis inclinata Fontaine, in Diller and Stanton, Bull. Geol. Soc. Amer., 



vol. 5, 1894, p. 450. 

 Cladophlebis, sp., Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, p. 78, pi. 



19, fig. 2. 

 Pecopteris strictinervis Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, p. 84, 



pi. 13, figs. 6-8; pi. 19, fig. 9; pi. 20, fig. 3; pi. 22, fig. 13; pi. 170, figs. 5, 6. 

 Pecopteris ovatodentata Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, p. 



85, pi. 15, fig. 8; pi. 22, fig. 12; pi. 23, fig. 1. 

 Pecopteris microdonta Fontaine, Monogr. U. S. Geol. Snrv., vol. 15, 1890, p. 85 



pi. 19, fig. 8; pi. 20, figs. 5, 11. 

 Pecopteris rirginiensis Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, p 



82, pi. 8, figs. 1-7; pi. 9, figs. 1-6; pi. 24, fig. 2; pi. 169, fig. 3.— Fontaine 



in Ward, Monogr. U. S. Geol. Surv., vol. 48, 1906, pp. 480, 538, 552, pi. 116 



figs. 3, 4. 

 Pecopteris constricta Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, p. 86 



pi. 20, figs. 1, 2, 4. — Fontaine, iu Ward, Monogr. U. S. Geol. Surv., vol. 48 



1906, p. 519. 

 Pecopteris socialis Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, p. 87 



pi. 21, fig. 7 (not Heer, 1882). 

 Pecopteris angustipennis Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, p 



87, pi. 21, fig. 10. 

 Pecopteris cf. virginiensis Yokoyama, Journ. Coll. Sci. Japan, vol. 7, 1895, p. 220, 



pi. 24, fig. 1. 



Description. — The American material which the writer refers to 

 this species is much more abundant than that from abroad, and 

 the following diagnosis may be attempted: 



Frond bipinnate or tripinnate. Pinnae elongate, linear in outline.^ 

 Pinnules approximate, variable in outline, usually obtuse and becom- 

 ing united distad to form a pinnatifid pinna, which is then constricted 

 and slightly decurrent at the base. Venation of the CladopTilehis 

 type not well seen in the smaller pinnules because of their coriaceous 

 texture. 



Tliis is another cosmopolitan species of Cladoplilebis which may 

 be composite in nature and which, as commonly preserved in frag- 



1 The single form which Fontaine identified with this species has pinnae which shorten rapidly, giving 

 the frond a deltoid form, and may be properly referable to the allied species Cladoplilebis nngeri. 



