Maryland Geological Survey 361 



below and not out of proportion to the size of the fronds is shown by 

 a most casual examination of the considerably macerated and much 

 flattened specimens, and is clearly indicated by the specimens photo- 

 graphically reproduced on the accompanying plates. 



In collections from the Cretaceous of Japan, Stopes has been fortu- 

 nate enough to obtain petrified material of the leaves of Nilsonia 

 orientalis Heer which is described at length/ This species is one of the 

 Tgeniopteris-like species, Seward in his Wealden flora ^ having suggested 

 that it was a Tceniopteris, and JSTathorst ^ having proposed that the closely 

 allied Nilsonia tenuinervis JSTathorst would have its botanical aflBnity more 

 clearly indicated by the name Nilsoniopteris. 



It is interesting, therefore, to find that the internal anatomy of 

 Nilsonia orientalis Heer is clearly gymnospermous rather than fern-like 

 and exactly of the type which might be regarded as primitively 

 cycadean. 



ISTiLSONiA OREGONENSis (Fontaine) Berry 



Angiopteridium strictinerve Fontaine, 1906, in Ward, Mon. U. S. Geol. 



Survey, vol. xlviii, 1905, pp. 240, 511, pi. Ixvi, figs. 5-7; pi. ex, fig. 12 



(non Font., 1890). 

 Sapindopsis oregonensis Fontaine, 1906, in Ward, Mon. U. S. Geol. Surv., 



vol. xlviii, 1905, p. 268, pi. Ixix, figs. 15-17. 

 Nilsonia oregonensis Berry, 1910, Proc. U. S. Natl. Mus., vol. xxxviii, p. 637. 



Description. — Frond simple, unsegmented in all the specimens col- 

 lected, lanceolate in outline, with equally pointed apex and base. Length 

 apparently about 7 cm. to 15 cm. and greatest width, which is midway 

 between the apex and the base, 1.2 cm. to 1.6 cm. Texture coriaceous. 

 Eachis stout, prominent below. Lateral veins close and parallel, the 

 great majority simple but an occasional vein forking dichotomously. 

 Angle of divergence large, varying from 55° in the apical part of the 

 frond to 85° in the median and basal portions. 



^ Stopes, Ann. of Botany, vol. xxiv, 1910, pp. 389-393, tf. 1, pi. xxvi. 



^ Seward, Wealden Fl., pt. i, 1894, p. 123. 



^Nathorst, Kungl. Svenska Vetens Akad. Handl., Band xliii, 1909, p. 29. 



