670 GEOLOGY OF THE YELLOWSTONE NATIONAL PARK. 



opposite or .sul)oi)po8ite, nearly at right angles to the rachis, long-lanceolate, 

 rather abruptly acuminate, cut to within a ver}' short distance of tlie rachis; 

 nervation simple, consisting of a strong straight midvein and numerous 

 (about 20) ])airs of opposite, parallel, unln-anched, lateral nerves; fruit 

 dots small, round, on the backs of the nerves midway between the midvein 

 and the margin. 



This beautiful species is rej^resented by several specimens, tlie best of 

 whicli is shown in fig-. 8. The pinnules are opposite or subopposite. They 

 are long, slender, and pointing upward. The nervation is very regular, 

 consisting of the strong midvein and Is to 2(1 or more pairs of opposite 

 parallel veins. The fruit dots are distinct, though small, and borne on the 

 veins midway betAveen the midvein and margin. 



This species is closely allied to Lasfrca r/oldimia (Lx.) Kn.,' from the 

 Denver beds of Grolden, Colorado. It does not so closely resemble the 

 figure given by Lesquereux as it does certain forms that have been referred 

 to it in my forthcoming monograph of the Laramie and allied formations. 

 The type of the species is described by Lesquereux as having 5 to 7 pairs 

 of nerves, while the forms that I have referred to it have 10 pairs, with 

 no other apparent diiference. Dnjopteris ivcedii, as stated, has 18 to 20 or 

 more pairs. The pinnules are from 10 to Ki mm. long and about o mm. 

 broad, whereas those of L. goldiana are only 7 to 9 mm. long and 3 or 4 

 nun. liroad. 



Froni this it is clear that these two species are quite closely related, 

 and possiblv a larger series of specimens might show them to be identical, 

 but for the present it is best to regard them as different. 



I have named this species in honor of Mr. Walter Harvey Weed, by 

 whom the first specimens were collected. 



Habitat: Yellowstone River, breccia in wall of canyon above mouth 

 of Hellroaring Creek (PI. LXXXI, fig. 2); collected by Walter Harvey 

 AVeed, October 13, 1887. Cliff on Yellowstone River (left hand), short 

 distance above mouth of Hellroaring Creek (PI. LXXX, fig. 8); collected 

 by F. H. Knowlton, August 10, 1888. 



' This was first called Aapidium i/oldianum by Lesquereux (Seventh Ann. Rept., 1873 p. 393). but was 

 later changed to Lastrea {Goinopla-ii,) iioldiana (cf. Tert. Fl., p. 56, PI. IV, tig. 13). 



