294 THE POTOMAC OR YOUNGEE MESOZOIC FLORA. 



FlCOPHYLLUM SEEEATUM, Sp. IIOV. 

 Plate CXLV, Fig. '2 ; Plate CXLIX, Fig. 9. 



Leaves of medium size, strongly serrate-toothed, teeth often irregular 

 in size, sometimes double, acute, and directed forwards ; shape of the leaf 

 not fully disclosed, but apparently elliptical ; midnerve proportionally very 

 strong, lateral or primary nerves very slender, not fully disclosed, but ap- 

 parently forming by the union of the branches of the primary nerves 

 irregular large meshes ; ultimate nervation not seen. 



Locality : Fredericksburg ; very rare. 



With the exception of the toothing this leaf is very much like F. ten- 

 uinerve. It is somewhat similar to Quercus Johnstrupi^ Heer, from the 

 I'atoot beds of Greenland, but the Potomac plant is larger and has a dif- 

 ferent nervation. 



FlCOPHYLLUM EUCALYPTOIDES, Sp. nOV. 

 Plate CLXIV, Figs. 1, 2. 



Leaves of medium size, narrowed towards the base and summit, rapidly 

 rounded towards tlie base, prolonged at the summit into an acute or nuicro- 

 nate point ; leaf-substance very thick, with a dense glossy epidermis ; mid- 

 nerve proportionally strong and continuing strong to near the summit; 

 lateral or primary nerves extremely slender, closely placed, going off at 

 nearly equal intervals, subparallel, curving forwards, sending off obliquely 

 delicate bi'anches, which split up dichotomously and anastomose to form 

 elongate, subrhombic, irregular meshes, ending near the margin in a fine 

 nerve, which runs for some distance nearly parallel to the margin. 



Locality : 72d mile-post, near Brooke ; very rare. 



The leaves seem to have been attached in a pinnate manner. In the 

 marginal nerve and the slender primaries it resembles HucaJyptus. It is a 

 good deal like Ficus ma(jnolktifolia Lesq., Cretaceous and Tertiary Floras, 

 PI. XVII, Figs. 5, 6. 



FICUS Tournef 



The genus Ficus is represented in the Potomac flora doubtfully by 

 only two species, and these have, so far as found, very few individuals. If 

 present, it seems to be newly introduced. 



' Flor. Foss. Arctica, vol. 7, PI. LVI, Figs. 7-12. 



