FOSSIL FLOEA. 6(i7 



evidently of the same species, are stems or rachises fully -S mm. thick. There 

 is some evidence to indicate that they were combined into a very large 

 frond, but it is not conclusive. The longest example is about 20 cm. long 

 and spreads about 9 cm. The longest pinna (PI. LXXX, fig. 9) is preserved 

 for 9 cm. and still lacks the terminal portion. The pinna^ vary in width 

 from 10 to 24 mm., depending upon the poi'tion taken. 



The pinnfe are cut into oblong acuminate pinnules, the sinus some- 

 times extending- to within one-third of their length of the base, but usually 

 to about half the length. Pinnides with a slender midnerve and 7 to 10, 

 iisually 9, pairs of close, unforked nerves. The lower nerves of adjoining- 

 pinnules unite at a low angle and pass upward and end in the sinus. 



Fruit dots were observed only on one small fragment (PI. LXXIX, 

 fig. 2). They are obscure, but as nearly as can be made out thev are 

 oblong and near the margin of the pinnules. Unfortunately none f)f the 

 larger specimens are fruiting, lint apparently thev all belnng to the same 

 species. 



I do not recall any fossil species to which this seems to be allied. A 

 number that have been described resemble it, liut none closely enough to 

 constitute specific similarity. 



I have named this species in honor of Prof. Joseph P. Iddings, of the 

 University of Chicago, who pointed out the locality which aff'orded the best 

 specimens. 



Habitat: Yellowstone River, al)ove mouth of Hellroaring Creek (figs. 

 3, 10); bank of Yellowstone, one-half mile below mouth of Elk Creek, base 

 of bluff (figs. 2, 9); collected by F. H. Knowlton from Fossil Forest Ridge, 

 bed No. 6, "Platanus Ijed," August, 1888. One specimen collected by 

 Lester F. Ward and F H. Knowlton, August, 1887. 



ASPLENIUM MAGNUM U. Sp. 



PI. LXXIX, figs. 5-8, Sa. 



Frond simple, pinnatifid, sometimes nearly pinnate below, long lance- 

 olate in outline, from a regular obtusely wedge-shaped base, and extending 

 into a long slender apex; cut into numei-ous, mainly alternate, ovate, sharp- 

 pointed lobes, those at the base being sometimes cut nearly to the rachis, 

 those above less and less until the apex is nearly entire; nervation of the 



