DESCRIPTION OF SPECIES. at 
GLEICHENIA Zipper Heer ?. 
Pl. Il, fig. 5. 
Gleichenia Zippei Heer, Fl. Foss. Arct., Vol. I, p. 79, Pl. XLIII, fig. 4; Vol. III, Part 
II, p. 44, PI. IV, figs. 1-5; Pl. V, figs. 1-9; Pl. VI, figs. 1-3; Pl. VII, fig. 2. 
Pecopteris Zippet Corda in Reuss, Versteinerungen d. Bohm. Kreidef., Abth. II, p. 95, 
Pl. XLEIX;, figs. 2, 3. 
Gleichenia Rinkian«w Heer, Fl. Foss. Aret., Vol. I, p. 80, Pl. XN LITT, fig. 6. 
We have occasionally found fragments of the fronds of a Gleichenia 
which I have been unable to distinguish trom that so fully illustrated in 
Heer’s Kreide Flora (Fl. ‘Foss. Aret., Vol. HII, Part IT), and to which he 
gives the above name. The plant was evidently a delicate one, and it is 
much less perfectly preserved than the associated ferns which I have 
referred to the genus Anemia. The fronds being much broken up, it is 
impossible to say whether or not we have united under one name plants 
which belong to different species. It has been thought, however, that an 
error of synthesis would be less mischievous than one of analysis, and it 
has seemed a fruitless labor to attempt to define species sharply where the 
material is defective, and when it is certain that in future years the exploita- 
tion of the New Jersey clay beds will permit the accumulation of abundant 
material, and that in better state of preservation. 
The genus Gleichenia was evidently widespread in the Cretaceous age, 
and there were many species of the genus in Europe and America. In the 
flora of the Amboy Clays other ferns are more numerously represented, if 
we can judge by the collections already made. It is true, however, that 
the distribution of species is somewhat local in the clay beds, and a treasury 
of specimens and perhaps species may at any time be discovered. The 
most abundant of the ferns which I have referred to Gleichenia is that which 
corresponds best with Heer’s description and illustrations of G. Zippei. The 
frond would seem to have been more open than most of those figured by 
Heer, but this is proved by his illustrations to be a variable character. The 
fructification is present on some of the specimens found at Woodbridge, 
and this has altogether the character of that figured by Heer. The pin- 
