74 THE OLDER MESOZOIC FLORA OF VIRGINIA. 



the black Triassic slate of Raibl. Our plant is most like the Pterophyllum 

 giganteutn, Schenk, a plant which Schimper names Macropterygium Schenhii. 

 But Schenk's plant has the bases of the leaflets proportionally much more 

 narrowed than they are in ours, and the leaflets appear to be laminae, split 

 by a peculiar mode of Assuring out of a broad leaf; and, besides, the nerves 

 are not nearly so strong as they are in the Virginia fossil. I am all the more 

 inclined to consider the Virginia plant not to be a Macropterygium, since the 

 other species, M. Bronnii {Pterophyllum Bronnii of Schenk) is a flabellate 

 leaf, cut into segments, and not unlike Nceggerathia. I have in no case 

 seen the terminations of any of the leaflets, although I have found them 30 

 centimeters long. On the whole the plant agrees well with the diagnosis 

 of the genus Ctenophyllum, the only difference being, perhaps, the slight 

 expansion of the bases of the leaflets upon the midrib. This feature, how- 

 ever, is to be seen in the figures of Ctenophyllum Braunianum, given by 

 Schenk on plate xxxviii of his "Foss. Flor. d. Grenzscht." Should the ter- 

 minations of the leaflets be acute, it might well be a Dioonites, as limited by 

 Schimper. It resembles Pterophyllum Footeanum, Feist., from the Upper 

 Gondwanas of Vemavaram, as described by Feistmantel in the "Foss. Flor. 

 of the Upper Gondwanas," series II, plate vi, figs. 1-6, but is a much larger 

 plant. It is of the same type of plants as those fine Cycads, Pterophyllum 

 Kingianum, Feist., P. Morrisianum, Old., P. Carterianum, Old., P. distans, 

 Morr., from the Rajmahal Group of India. It is, however, a larger and finer 

 plant than any of these. 



Dr. Newberry, in Macomb's Report, gives, plate vi, fig. 7, a fragment 

 of a large plant which he calls Pterophyllum robustum, which is much like 

 our plant, though smaller. As it seems to me, the ends of the leaflets in 

 Newberry's plant are not preserved, but the leaflets are broken off. Pro- 

 fessor Rogers, in his paper before mentioned, speaks of finding great num- 

 bers of strap-shaped leaflets in the dark shale not far above the main coal, 

 which, he says, are among the most abundant of the fossils of this shale. 

 These impressions he attributes to a large Cycad, but as he saw neither 

 their insertions nor their terminations he could not be sure as to their exact 

 nature. From his description, they were clearly detached leaflets of Cteno- 

 phyllum grandifolium. 



