DESCRIPTIONS OF SPECIES. 7 



is also reticulated; but iu Lesquereux's plaut the midrib of the pinna is 

 much stronger and is channeled, while the lateral nerves anastomose much 

 less frequently, and it is evident that the specimens represent distinct 

 species. Until the fructification of this fern shall be discovered, its generic 

 relations can not be said to be established. However, the resemblance in 

 nervation and proportions of the frond to Acrostichum is so strong that 

 the reference to that genus seems justifiable. 



Mr. J. Starkie Gardner, in his Monograph of the British Eocene Flora, 

 Vol. I, p. 26, figures and describes a large Chrysodium found in the Bag- 

 shot beds of Bournemouth, England, which he calls Chrysodium Lansceanum, 

 and which closely resembles that now under consideration. I find hardly 

 any points of difference, except that Mr. Gardner represents the Bourne- 

 mouth species as having a strong pinnate frond which terminates in a single 

 lanceolate pinna which is drawn down to an acute base; whereas in our 

 species, as will be seen by reference to the figures now published, the frond 

 terminates above in a palmate divergence of the terminal and upper lateral 

 pinnae, the bases of which all coalesce. It is interesting, however, to find 

 a species so closely allied to this foreign one at nearly the same geological 

 level in this country. 



Formation and locality: Tertiary (Green River group). Green River, 

 Wyoming. 



Pteris PENNiEFORMis Heer. 1 



PL XLVIII, fig. 5. 



Fl. Tert. Helv., Vol. I (1855), p. 38, PL XII, figs. la-Id. 



Pteris pseudopennczformis Lesq. ? Tert. Fl. (1S7S), p. 52, PL IV, figs. 3, 4. 



Formation and locality: Tertiary (Miocene!). Currant Creek, Oregon. 



Note. — I have been unable to find any manuscript relating to the above, 

 except brief memoranda on plate and specimen to the names and locality here 

 quoted. — A. H. 



Pteris Russellii Newb. 

 PL LXI, figs. 1, la. 

 Proc. IT. S. Nat. Mus., Vol. V (March 21, 1883), p. 503. 



"Frond large, pinnate; pinna; crowded, linear in outline, narrow, 

 long-pointed above, attached to rachis by entire base; decurrent; length, 



