94 MESOZOIC FLORAS OF UNITED STATES. 



NiLSONiA NiPPONENSis Yokovama. 



PI. XVII, Figs. S-10. 



1889. Nilsonia nipponensis Yok. : Journ. Coll. Sci. Imp. Univ. Japan, Vol. Ill, 

 Pt. I, p. 42, pi. vi, fig. Sd; pi. xii, fig. 6; pi. xiii, fig. 1. 



Several specimens of a plant were found at localities Nos. 2 and 

 14 that agree closely with Yokoyama's Nilsonia nippo7iensis, except 

 that the segments are not quite so much rounded off on the posterior 

 margins of the ends. Yokoyama's specimens, however, seem to be 

 somewhat distorted, and even this unimportant difference may be 

 accounted for in that way. It is probable that several of the forms 

 from the Jurassic of Siberia, called by Heer Pterophyllum and Anomoz- 

 amites, belong to the same species. Their segments agree exactly in 

 form, and the appearance of the midrib may be due to the fact that 

 the lower surface of the plant is presented uppermost. The forms 

 alluded to are Ayiomozamites Schmidtii and Pterophyllum Helmersenianum. 

 The segments of this plant are broad and short. The nerves are slender, 

 but sharply defined. They are simple and parallel to one another and 

 to the margins of the segments. 



The fragment given in PI. XVII, Fig. 8, is apparently from the 

 middle part of a leaf. Fig. 9 shows several segments of this enlarged. 

 Fig. 10 shows the basal part of a leaf and illustrates the tendency to 

 irregularity of the segments in this part of the leaf. The segments 

 on opposite sides of the midrib are quite unequal in width, and at the 

 end of the fragment the segments are succeeded by a narrow lamina 

 on each side that is entire. The midril^ of this specimen has great 



strength. 



Nilsonia compta (Phillips) Goppert. 



PI. XVII, Figs. 11-14. 



1828. Pterophyllum Williams onis Brongn.; Prodrome, pp. 95, 199 (nomen)." 



1829. Cycadites comptus Phill.: Geology of Yorkshire, pp. 148, 189, pi. vii, fig. 20. 

 1833. Pterophyllum comptum (Phill.) L. & H.: Foss. Fl. Gt. Brit., Vol. I, p. 187, 



pi. Ixvi. 



a As no description or figure ever accompanied the use of this name it may, although antedating all others, 

 be dropped as a nomen nudum ; still, as Brongniart in his Tableau, 1S49, distinctly enters it as a synonym 

 of Nilsonia «ompto, and as numerous authors (Morris, Goppert, Unger, etc.) have introduced it into the 

 literature, it can not well be omitted from the synonymy. — L. F. W. 



