72 THE OLDER MESOZOIC FLORA OF VIRGINIA. 



The nerves are usually six in number, but some of them are more 

 conspicuous than others, and then the middle one is generally the strongest. 

 They are, in all cases seen by me, simple, and are somewhat thickened at 

 base. The central ones stand at right angles to the midrib, or in the case of 

 the obliquely inserted leaflets of the middle and upper part of the leaf, they 

 make the same angles with the midrib that the leaflet does. In all cases 

 the lateral nerves go off obliquely, and make a more acute angle with the 

 midrib than the central ones do. All the specimens fcmnd belong to the 

 var. a of Goeppert, or that with longer leaflets, and these attain a greater 

 length than do those of Goeppert's plant. There can be no doubt, however, 

 that this is the same species with that described by Goeppert from the 

 Rhretic formation of Theta, near Bayreuth, and figured on Plate xxxviii, 

 Figs. 1-10. Our plant, however, is much more like the plant described by 

 Anclrae in "Foss. Flor. Siebenb.," with the name Zamites Dunkerianus, 

 and depicted on Plate XI, Figs. 2, 3. Schimper unites this plant with 

 Ctenophyllum Braunianum. This plant of Andrae's is precisely like the Vir- 

 ginia fossil, except that it is smaller than the largest Virginia specimens. 

 Many of the Virginia specimens are no larger, however, than this of Andrae. 

 Brongniart has given a figure of a plant sent to him from the Richmond 

 Coal Field, which he named Filicites vittarioides. It is clearly the plant 

 now being described. The only difficulty in the way of identification is 

 the statement of Brongniart, that the leaflets have regularly two nerves. 

 This, I think, is a mistake, made from the fact that one or two of the nerves 

 are often stronger than the rest. Brongniart had only an imperfect speci- 

 men, and it is not to be supposed that he could make out from it the true 

 condition of the nerves. Professor Rogers, in his paper before referred to, 

 describes a plant from the Richmond Coal Field, as Zamites obtusifolius, and 

 gives a figure of it. He calls attention to the resemblance that it bears to 

 Brongniart's plant. Zamites obtusifolius is clearly our plant, but is of smaller 

 size than the largest obtained by me. Emmons found a plant in the Meso- 

 zoic of North Carolina, which he considered as possibly Rogers's Zamites 

 obtusifolius. He gives a figure of it in fig. 85 of his American Geology. This 

 plant seems to be clearly the same with the form of Ctenophyllum figured 

 by Schenk on plate xxxviii, fig. 1, of his "Foss. Flor. d. Grenzscht." 



