392 GEOLOGICAL SURVEY OF THE TERRITORIES. 



distinct, and form two rows of polygonal areolae in passing up to the bor- 

 ders ; in this variety (?), the veinlets are merely forked in going up. 



This small form is closely allied to Woodwardites arcticus, Heer, differ- 

 ing, however, by the nervation. The fragments representing Heer's 

 species are, like those of Black Butte, too small for an exact comparison. 

 His described specimens are from Greenland and from Alaska. 



Hahitat. — Black Butte ; Wyoming. 



Pteris penn^formis, Heer. 



Pinnae long, linear-lanceolate, taper-pointed, entire to above the mid- 

 dle, undulate upward, serrate at or near the point, thickish ; medial 

 nerve thick, especially toward the base of the leaflets, where it is bi-groo ved 

 and three-striated ; veins in an acute angle of divergence, close, thin, 

 mostly simple, or forking once. The fragments of leaves or pinnae, as 

 described here, closely resemble the species of Heer, (Fl. Tert. Helvet., 1, 

 p. 38, PI. xii, Fig. 1,) differing slightly by the borders, which, serru- 

 late at or near the point, are undulate or distantly and obtusely den- 

 tate above the middle, and entire downward. Heer describes his spe- 

 cies as serrulate near the point and entire downward. In comparing 

 our specimen to the figure marked above, the denticulation apjiears 

 merely more marked in the American form. 



This species has been described already in Hayden's Eeport for 1871, 

 (p. 283,) from specimens from Henry's Fork, too fragmentary for positive 

 determination. 



Hahitat. — Golden, Col. 



Pterts affinis, sp. nov. 



Frond simply pinnate ; pinnae subcoriaceous or thickish, short, about 

 5 centimeters long, oblong-lanceolate, broader at the middle, rapidly 

 tapering to a slightly obtuse point, gradually narrowed downward, and 

 rounded to the point of attachment ; borders undulate ; nervation thin, 

 but very distinct ; veins open, curving from the middle nerve to the 

 borders, slightly more deflexed downward in reaching the midrib, dicho- 

 tomous, none simple, or scarcely any, forking once or twice, rarely three 

 times. 



Different from the former by its nervation, shorter obtuse pinnae, undu- 

 lately crenate borders, and thinner substance of the leaves. From P. 

 anceps, Lesqx., (Hayden's Eeport, 1872, p. 376,) it differs especially by 

 more distant and more oblique veins. 



Habitat. — Golden ; rare like the former, but obtained in better speci- 

 mens. » 



Pteris erosa, Lesqx. 



Pinnae broadly-lanceolate or ovate-lanceolate, taper-pointed or acu- 

 minate, serrate upward, with crenulate or lacerate borders below; 

 medial nerve thick ; veins oblique, straight, mostly simple, forking 

 near or at the base, rarely above the middle, distant, parallel. It has 

 been formerly described in Supplement to Hayden's Eeport, 1871, (p. 12.) 



By its nervation and the form of its pinnae this species is related to 

 P. longifolia, L., or to some of its varieties with serrate borders. 



Habitat. — Eaton Mountains, where the first incomplete fragments were 

 discovered ; Golden, where it was found in more perfect specimens. 



Pteris subsimplex, sp. nov. 



Pinnae thick, coriaceous, simple, entire, linear-lanceolate, narrowed in 

 curving to the base, (point broken,) large, varying in size, from 2 to 4 

 centimeters broad, and at least 10 to 12 centimeters long ; middle nerve 



