256 Systematic. Paleontology 



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



xlviii, 1905, pp. 510, 538. 

 Dryopteris parvifoUa Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. 



xlviii, 1905, p. 486 (non p. 541, pi. cxiv, fig. 7). 

 Cladophlebis Ungeri Ward, 1906, in Font., in Ward, Mon. U. S. Geol. Surv., 



vol. xlviii, 1905, pp. 228, 510, 538, pi. Ixv, figs. 15, 16. 

 Pecopteris hrevipennis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., vol. 



xlviii, 1905, p. 510. 

 Cladophlebis Ungeri Knowlton, 1908, in Diller, Bull. Geol. Soc. Am., vol. 



xix, p. 386. 

 Cladophlebis Ungeri Berry, 1911, Proc. U. S. Natl. Mus., vol. xli, p. 318. 



Description. — " Pecopteris fronde gracili bipinnata, pinnis petiolatis 

 linearibus alternis, pinnulis adnatis opposite ovato-oblongis obtusis re- 

 motiusculisj nervo obsoleto venisque obliteratis; rhachi tenui tereti." — 

 Dunker, 1846. 



A more extended and satisfactory diagnosis is that written by Profes- 

 sor Fontaine for his Aspidium Dunheri, which will answer not only for 

 that material but for all of the other supposed species founded by Fon- 

 taine upon various fragments of Cladophlehis Ungeri. It is as follows : 



" Frond bipinnate or tripinnate^ arborescent ; principal rachis stout 

 and rigid; ultimate pinnae alternate, short, linear-lanceolate; pinnules 

 alternate or subopposite, short, closely placed, narrowed at the base, cut 

 more or less deeply into lobes or teeth which are ovate or oblong, obtuse 

 or subacute, very small, those of the fertile portions of the frond stand- 

 ing nearly perpendicular to the rachis and having in each lobe or pinnule 

 a simple lateral nerve which bears a sorus on its summit, those of the 

 sterile and more common portions more obliquely placed, mostly sub- 

 acute, with nerves in each lobe that fork simply in the upper ones, and 

 in the lower ones are composed of a midnerve with alternate simple 

 branches; leaf-substance thick; sori very minute, club-shaped or ellip- 

 tical, visible distinctly only with the help of a lens, and present only in 

 the pinnules of the lower part of the pinnae, and mostly found on the 

 lobes towards the base of these." 



This species was described by Dunker in 1846 from the Wealden of 

 northern Germany as Pecopteris Ungeri and Pecopteris polymorplia. 

 Schimper in 1869 renamed the latter Pecopteris Dunheri as the specific 



