76 THE POTOMAC OE TOUNGEE MESOZOIG FLOEA. 



Most of the specimens figured come from Fredericksburg. PI. IX, 

 Fig. 2, a form with opposite pinnae, comes from the 72d mile-post, near 

 Brooke. PI. XIII, Fig. 3, comes from the hill-side near Potomac Run. 

 It has the lobes more rounded than usual. The pinnules are often decur- 

 rent some distance on the rachis. 



This plant is not very near any described fossil known to me. It 

 may be compared with Cyathed Tchihatchewi, Schmalhausen,' but shows 

 obvious differences. In the shape of the pinnules the species is nearest to 

 Pecopteris horeaUs, Brong., as figured by Heer,- from the Kome beds, but 

 this latter has the nerves single. 



Cladophlebis, sp.? sp. nov. 



Plate X, Figs. 5, 8; Plate XX, Fig.7. 



Nature of frond and pinnae unknown; pinnules alternate, oblong, 

 acute, slightly falcate, attached by a Avidened base under a large angle; 

 midnerve vanishing before attaining the tip of the pinnule; lateral nerves 

 not seen; leaf-substance thick. 



Localities: Fredericksburg; hill-side near Potomac Run; at both 

 places very rare. 



Cladophlebis inclinata, sp. nov. 



Plate X, Figs. 3, 4 ; Plate XX, Fig. 8. 



Frond bipinnate or tripinnate, arborescent (!); pinnae of ultimate order, 

 opposite, short; pinnules, ovate-lanceolate, acute, inclined forward, alter- 

 nate, attached by the whole of the widened base, separate to the base, 

 slightly falcate ; midnerve of pinnules slender above the base, but con- 

 tinued to near the apex of the pinnules ; lateral nerves once forked. 



Locality: Near Telegraph Station; not uncommon. 



This plant is a good deal like some of the forms of C. acuta, as given 

 in PI. X, Fig. 6, but the pinnules are smaller and not united at the base, 

 and none of the lateral nerves are more than once forked. It is so much 

 like Pteris AlbertsiP Heer, found in the flora of the Atane beds, that it is 



' Beitr. Jura Flora Russland's, PI. Ill, Fig. 3. St. Petersburg!!, 1879 

 2 Flor. Foss. Arc, vol. 6, Pt. 2, PI. II, Figs. 9% 10. 

 Ibid., PI. XVI, Figs, ry, 6; PI. XXVIII, Figs. 1-3 ; PI. XL VI, Figs. 22-24. 



