OLDER POTOMAC OF VIRGINIA AND MARYLAND. 495 



Ephedrites ? VERNONENSis Fontaine n. sp. 

 PI. CVII, Fig. 8. 



The Mount Vernon locality yielded a pair of small nut-like seeds that 

 seem to have been closely approximate in growth. On the inner side, 

 where they touched each other, they have nearly straight margins. On 

 the outer side the margins are curved. At their bases they are rounded 

 and obtuse. At their summits they are acute. They seem to have 

 been covered by a small leaf or scale. They do not stand out convex 

 on the matrix, and hence were probal^ly thin in texture. They resemble 

 the paired seeds from the Jurassic of Siberia, described by Heer as Ephe- 

 drites antiquus." Of course the amount of material is not sufficient to fix 

 the position of these seeds, but they may provisionally be placed in the 

 genus Ephedrites. 



The specimen was collected on November 6, 1892. 



Glyptostrobus (Taxodium) brookensis (Fontaine) Ward. 

 PL CX, Fig. 1. 



1S89. Taxodium {Glyptostrobus) IrooTcense Font.: Potomac Flora (Monogr. U. S. 



Geol. Surv., Vol. XV), p. 254, pi. cxxii, figs. 1, la, lb; pi. cxxiv, figs. 3, 3a, 



4, 4a, 5-7, 7a, 8, 9; pi. cxxxi, figs. 5, 5a; pi. clxv, figs. 1-3; pi. clxvi, figs. 4, 



4a, 7; pi. clxvii, fig. 3. 

 1895. Glyptostrohus IrooTcensis (Font.) Ward: Fifteenth Ann. Rep. U. S. Geol. Surv., 



189.3-94, p. 359. 



There are 9 specimens of this conifer in the Mount Vernon flora. 

 Some of them are very fine. The specimen given in PI. CX, Fig. 1, is 

 one of the best of these. The leaves on the ultimate branches are beauti- 

 fully preserved. This is due to the fineness of texture of the matrix of 

 the Mount Vernon clay. One of the finely preserved specimens has 

 associated with it a cone that seems to be an immature female one, 

 belonging to this plant. It is, however, not certainly attached to a twig. 

 The cone is oblong in shape, about 7 mm. long, with faintly shown scales 

 that seem to be chaff )^ 



The specimens were all found at the Mount Vernon locality, most 

 of them, including the one figured, on November 6, 1892, but some on 

 October 16, 1892, and two on May 14, 1893. 



«F1. Foss. Arct., Vol. IV (Beitr. z. .Jura-Fl. Ostsibiriens), p. 82, pi. xiv, fig. 



