DESCRIPTION OF MIOCENE SPECIES FROM SPECIMENS 



OBTAINED IN THE SO-CALLED BAD LANDS 



OF DAKOTA. 



CRYPTOGAMS. 

 FILICES. 



ASPLENIUM, Linn. 



Aspleniuni tenerum, sp. nov. 



Plate XLViA, Figs. 1, 2. 



Bipinnate; pinniB-linear, narrowly lanceolate; secondary pinnae short, oblique, 

 parallel, lanceolate, pinnately lobate; lobes distinct to near the base, oblong or obovate, 

 obtnse; primary nerves slightly flexuous, pinnately dichotomous ; lateral nerves at an 

 acute angle of divergence, forking once or twice. 



There is a number of fragments of this species, all of the same char- 

 acter. The lower secondary pinnae, a little more than li centimeters 

 long, 5 millimeters broad at base, are gradually shorter and narrower in 

 ascending, the lobes becoming also shorter and less deeply cut. 



This species has a marked affinity to Sphenopteris Blomstrandi, Heer, 

 "Fl. Arct.," i, p. 155, pi. xxix, figs, 1, 5, 9; but that has the secondary 

 pinnae shorter and broader, more or less unequilateral, deeply lobed, and the 

 medial nerve thin, dissolving upward, not continuous. Its nearest affin- 

 ity is with living species of Aspleniuni of the section of the DicksonioB, like 

 Dicksonia tenera, &c. 



Hah. — Bad Lands near Gilmore Station of the U. P. R. R. Commu- 

 nicated by Professor Wvi. Lenton. 



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