FLORA OF THE SHASTA FORMATION. ^35 



Sagenopteris OREGOJfENSis Fontaiiie nT comb. 

 PI. LXV, Figs. 36-38. 



1894. Sagenopteris latifolia Font, in Diller & Stanton: Bull. Geol. Soc. Am., Vol. V, 



p. 450. (PL LXV, Fig. 38.) 

 1895 [1896]. An^iopieridium oregonense Font, in Stanton: Bull. U. S. Geol. Surv., 



No. 133, p. 22 (nomea). (PL LXV, Figs. 36, 37.) 



Pinnules probably grouped in a digitate manner at the summit of 

 a principal stipe, number not known. Central pinnule broadly ellip- 

 tical, narrowing to the base, 6 cm. long, 3 cm. wide in the widest por- 

 tion, symmetrical and equilateral in form. Lateral pinnules inequi- 

 lateral and unsymmetrical, oblong-elliptical, narrowing gradually to 

 the base, 55 mm. long, 22 mm. wide in the widest portion. Both kinds 

 of pinnules are probably supported on short stipes. The nervation 

 is fine and closely placed. The anastomosis is formed on the same 

 plan as in S. nervosa, viz, by the junction of two adjacent nerves, or 

 by the junction of a branch with an adjacent nerve soon after forking. 

 It is, however, more frequent than in S. nervosa. The midnerve in 

 all pinnules is very strong in their basal portions and splits up into 

 nerves before reaching the middle portion. These latter, where the 

 midnerve is present, leave it at a small angle and proceed to the margin 

 of the pinnule with a very slight outward curvature. The midnerve, 

 unlike that of S. nervosa, is flat, and it is proportionally stronger in the 

 basal portion of the pinnule, although less woody in appearance. 



This plant differs from S. nervosa in a numl^er of points. It is 

 smaller in size. The midnerve differs in the points previously men- 

 tioned. The lateral and secondary nerves are closer and finer, and 

 they anastomose more frequently. The form of the pinnules in this 

 plant much resembles that of those of S. Nilsoniana (Brongn.) Ward 

 {S. rhoifolia Presl) of the Rhetic formation, but the nervation is closer 

 and finer, while the midnerve is not prolonged so far in the pinnule. 



While the number of features by which this plant differs from 

 S. nervosa is sufficient to justify its separation, provisionally, as a dis- 

 tinct species, still, as the amount of material is small, it is possible that 

 they ma}^ be the same, and in a larger number of specimens connecting 

 links might be found. 



