4 THE LATER EXTINCT FLORAS OF NORTH AMERICA. 



upper ones narrow lance linear, wedge-shaped at base, summit long-pointed, 

 acute margins coarsely toothed; nervation strongly marked, acute-angled, 

 medial nerve of pinnae vanishing toward the summit, secondary nerves 

 diverging from this at a very small angle, radiating to the margins, dichot- 

 omously forked." 



A number of figures are now given of a fern, specimens of which have 

 been collected at Point of Rocks, Wyoming; Golden and Erie, Colorado, 

 and Bellingham Bay and Carbonado, Washington. In general character it 

 so closely resembles Gymnogramma Haydenii, figured by Lesquereux (Tert. 

 Fl, PI. V, figs. 1-3), that it can hardly be considered distinct, but a few 

 minor differences render it possible that we have here only two closely allied 

 species. Lesquereux shows and describes the nervation of his fern as 

 finer and simpler than that represented in our figures; but he states that the 

 nervation is obscure in his specimens, and that it seems to have been buried 

 in the parenchyma. The same is true of the specimens before us, and the 

 distinctness of the nervation is exaggerated in the figures; but it can be 

 plainly made out in some portions of the frond, and is more open and 

 stronger than is shown in Lesquereux's plate. The reference of this plant 

 to Gymnogramma is conjecture only; and the question of its botanical 

 affinities can only be decided when fruiting fronds shall be found. The 

 fossil is a marked one, however, and the figures and descriptions of it will 

 serve a good purpose, whatever generic name maybe hereafter given to it. 



Previous to the description by Lesquereux (1871) Count Saporta had 

 described (Fl. Foss. Sezanne (1868), p. 315, PL II, fig. 4) a very similar 

 fern under the name of Asplenium subcretaceum. This was more fully illus- 

 trated by Gardner and Ettingshausen (Mon. British Eocene Flora, Vol. 

 I, Pt. II (1880), p. 45, Pis VIII and IX), and called by them Anemia subcre- 

 tacea. Lesquereux, Saporta, and the authors of the British Eocene Flora are 

 agreed in considering the specimens from Wyoming, Sezanne, and Bourne- 

 mouth as belonging to the same species. The large number of specimens 

 of the fern which I have from Point of Rocks and Puget Sound show that 

 while apparently identical with that figured by Lesquereux (Tert. FL, p. 59, 

 PL V, figs. 1-3), it differs so much from the foreign specimens that we must 

 regard it as at least a strongly marked variety. Some fragments of pinna? 

 figured by Mr. Gardner — such as those given on PL VIII, fig. 1, PL IX, figs. 

 3 and 5 — approach closely to the American plant, but we nowhere find here 



