270 THE POTOMAC OR YOUNGER MESOZOIC FLORA, 



Carpolithus mucronatus, sp. nov. 



Plate CXXXVI, Fig. 15. 



Seed of medium size, elliptical, Avidest towards the summit, ending in 

 a short rigid tip (mucro), narrowed gradually towards the base into a very 

 short stout pedicel, by which it is attached to the principal stem, marked 

 on the upper surfoce with three strong lines or ridges. 



Localities: 72d mile-post ; bank near Brooke ; very rare. 



This is probabl}^ a seed of Ceplialotaxopsis. 



CYCADEOSPERMUM Saporta. 



In the genus Cijcadeospermnm I place various smooth horny seeds, 

 which resemble those of cycadaceous plants more than those of conifers, 

 but which are alwa^^s found detached and isolated. This fact, and the 

 additional one that they are usually imperfectly preserved, render the 

 correct placing of these ijlants impossible. They are always few in num- 

 ber, and form a very insignificant element in the Potomac flora. 



Cycadeospermum acutum, sp. nov. 



Plate CXXXV. Fig. 12. 



Seed oval, acute, small, with a smooth, firm surface, obtusely rounded 

 at base. 



Locality : Ilill-side near Potomac Run. 



This small seed is very rare. It was found only isolated and not in 

 connection with any leafy twigs. The seed figured b)' Heer' as the seed 

 of Ginkgo sibirica are a good deal like this one. 



Cycadeospermum obovatum, sp. nov. 



Plate CXXXV, Fig. 13. 



Seed of medium size, obovate in form, narrowed towards the base, 

 where a trace of the pedicel is seen ; smooth and firm. 



Locality: Hill-side near Potomac Run ; rare. 



This seed is something like Carpolithus Virginiensis, but it is larger, 

 and besides is smooth and glossy on the surface. 



> Flor. Foss. Arctica, pt. 2, vol. 4, PI. XI, Figs. 13-20. . 



