236 OLDER MESOZOIC FLORAS OF UNITED STATES. 
portions of a pinnule magnified three diameters, in order to show the nervation, 
which is uncommon. I have very carefully studied it and failed to see some of the 
points given in Mr. Wanner’s Fig. 2. The nerves are more slender than is indicated 
in that figure and more closely placed. There is some indication of a toothing on 
the margins of the pinnules, but, as I see it, it is not so constant and regular as that 
indicated by Mr. Wanner. It appears to be a laceration of the margin at the termi- 
nation of some of the lateral nerves, that is due to accident in the splitting of the 
slate on which the impressions are found. The description is as follows: 
The midrib is strong and rigid. The pinnules are opposite or subopposite, and 
extremely long and slender. They are a little over 5 cm. long and only 4 mm. wide 
near their base. They are falcate, with the basal portion of the lamina on the upper 
side of the midnerve a good deal wider than that on the lower side, tending to form 
an ear. This upper basal portion overlaps the lower basal portion of the pinnules 
following next above, and all the pinnules are so closely placed as to overlap or touch 
at their margins. The pinnules narrow gradually to a subacute tip. In the lower 
portion of the pinnules there is a distinct midnerve, which is inserted on the rachis 
below the middle of the base of the pinnules. The midnerve disappears in the upper 
part of the pinnule, being split up into very long branches that fork at long intervals. 
These branches and the lateral branches sent off above the base are remarkable for 
their length and closeness of position, and for the fact that they diverge so slightly 
that they are almost parallel. The nerves at base on the upper side of the midnerve 
diverge more strongly to fill the ear. Some of the lateral basal nerves, especially on 
the upper side of the midnerve, go off from the rachis. Lateral nerves go off from 
the midnerve on each side so obliquely that they almost follow the course of that 
nerve. They fork at long intervals, and, as stated before, diverge so slightly that 
they and their branches are approximately parallel. The branches occasionally 
anastomose in a straggling, irregular manner, so as to form no regular and definite 
meshes. 
This plant may form the type of a new genus. It reminds one in its habit of 
Otozamites, especially of some of the forms of O. Bucklandii, as given by Schenk in 
Foss. Flor. der Grenzschichten, more especially of figs. 2, 8, pl. xxxiii, but the 
nervation and other points are different. The nervation, apart from the reticulation, 
resembles the peculiar nervation of some of the forms of Zamiopsis of the Potomac 
formation. It’may be compared with that of Z. insignis, Mon. U. 8. Geol. Survey, 
Vol. XV, pl. Ixv, fig. 4. It is, however, a plant quite different from any species 
hitherto described. But for the anastomosis it agrees well with the genus Clado- 
phlebis, and may be provisionally placed in that genus, with the name C. reticulata. 
The following is Mr. Wannevr’s account of it: 
No other specimen found here so completely presents the original in its entirety. 
The exceptionally well-preserved group of leaves, Fig. 1, Pl. X XI, showing the shape 
of the frond, angle of departure of the pinne and their shape, stands alone. Even 
the rootstalk, showing the points where the leaves were attached, as well as numer- 
ous slender rootlets, has left its plain impress upon the shale. 
A slightly mutilated basal end of a leaflet, Fig. 2, Pl. XXI, shows the auricle as 
well as the forking and anastomosing nerves. 
Locality.—N. C. R. R. cut, south of York Haven. 
