26 DESCRIPTION OF SPECIES. 



FILICES. 



SPHENOPTERIS, Brgt. 

 S p h e 11 o p t e r i s corrugata, Newby. 



"Later Ext. Fl. of North America," p. 10; "Illustr.," pi. ii, fig. 6. 



Frond unknown; pinnules ovate or cuneiform, narrowed at the base, obtuse, 

 lobed, and often plicate longitudinally; nerves distinct, dichotornous, branching from 

 the base. — (Newby.) 



HYMENOPHYLLUM, Klf. 



Hymenopliyllum cretaceum, Lesqx. 

 "U. S. Geol. Eep.," vi, p. 45, pi. i, figs. 3-4J; xxix, fig. 6. 



In describing this species I related it to the preceding from the 

 description given by the author, as I had not then seen the figures. These 

 indicate a degree of relation which cannot be positively ascertained on 

 account of the too fragmentary specimens. The fronds were evidently 

 large in the plants of this kind. The divisions are multiple and extremely 

 variable. The specimens may, therefore, represent pinnules derived from 

 divers parts of fronds of the same species. 



PECOPTERIS, Brgt. 

 Pecoptcris Nebraskana, Heer. 



"U. S. Geol. Rep.," vi, p. 46, pi. xxix, figs. 5, 5a. 



GLEICHENIA, Sw. 

 Oleichenia Kurriana, Heer. 

 "U. S. Geol. Hep.," vi, p. 47, pi. i, figs. 5-5e. 



Gleiclienia NorclenskiOltli, Heer. 



Plate I, Figs. 1, la. 

 Hardens "Ann. Rep.," 1874, p. 334, pi. ii, fig. 5. 



Fronds slender, bi-polypinnate; ultimate pinnae alternate, rigid, open, linear, 

 parallel; pinnules subcoriaceous, small, free, oblong-ovate, obtuse, rounded at base on 

 both sides, inclined upward ; secondary veins few, three or four pairs, the lower forking, 

 the upper simple. 



Though the American specimens of this species are small they show 



distinctly the essential characters of the species : the slender rachis of the 



ultimate pinnae rendered flexuous by compression of the basilar border of 



the pinnules, the very small leaflets free and rounded at base, and the 



disposition of the veins. The specimens which I have for examination 



are sterile. As seen and figured by Prof. Heer, the fructifications are those 



