DESCRIPTIONS OF SPECIES. 11 



This beautiful fern may be readily recognized by the rigid exactness 

 of its outline, the regularity and precision of its crowded nervation, and by 

 the falcate curvature of the extremity of the acute pinnules. From the 

 large angle made by the midrib of the pinnule with the rachis of the pinna 

 the number of the pinnules on the frond seems crowded. In some of the 

 pinnules the midrib has an elegant sigmoidal curve. This, with the parallel 

 curvature of the lateral veins, gives a peculiar, exact, and elegant aspect to 

 the plant. 



The specimen figured was collected by Rev. Thomas Condon, at Cur- 

 rant Creek, Oregon, where it occurs matted together in masses. Lesque- 

 reux has also found what he considers to be the same species at John Day 

 Valley, Oregon. 



Of the described species, Lastrea Fischeri Heer (Fl. Tert. Helv. Vol. I, 

 p. 34, PI. IX, figs. 3a to 3e), resembles this most, but our plant is stronger, 

 the pinnules are united for a greater portion of their length, are more acute, 

 have a more crowded nervation and a distinctive upward curve. Yet these 

 differences are rather of degree than kind, and hardly warrant th^ separa- 

 tion of the American and European plants. 



From the species described by Lesquereux as L. Goldiana and L. inter- 

 media (Tert. FL, p. 56, PL IV, figs. 13 and 14), this may be distinguished 

 by its acute, falcate, and more numerous pinnules. 



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



Aspidium Kennerlyi Newb. 

 PI. XVI, figs. 4, 5. 

 Boston Journ. Nat, Hist., Vol. VII (I860), p. 513. 



"Frond pinnate; pinna? deeply pinnatifid; pinnules oblong, obtuse, 

 somewhat curved upward, united at their bases, margins acutely denticu- 

 late, sometimes entire ; nervation strongly marked, secondary nerves mostly 

 once-forked, basal nerve of each pinnule on the lower side often twice- 

 forked." 



This elegant species seems to have grown in the greatest abundance 

 during the period of the deposition of the coal of Vancouvers Island, the 

 shales over the Newcastle coal being so closely packed with its fronds as to 

 show them crossing each other in every direction under every lamina that 

 is raised. From their very abundance and consequent interference it is 



