FOSSIL PLANTS. 85 
other and to other plants, and he takes the apparently sensible view that the 
Wealden Cyclopteris digitata Brong. (Baiera digitata Schenk) and the Rheetic 
Jeanpaulia Miinsteriana Ung., though perhaps members of the same botan- 
ical group, were generically distinct. 
Brongniart and Unger regarded Jeanpaulia as one of the Rhizocarpe, 
allied to Marsilia, but Schenk considers it a fern. He also supposes that it 
is allied to Hausmannia of the Wealden. Its relation with the later genus 
is, however, very doubtful. 
From the Amboy clays of New Jersey, the basal portion of the Creta- 
ceous system, and resting immediately upon the Triassic beds, I have ob- 
tained many specimens of Hausmannia, and, though there is a remote re- 
semblance in the mode of the division of the frond, there is a radical differ- 
ence in the nervation, and they probably have nothing in common. 
Equisetum Rocersr Schimper. 
PL XXII, Figs. 5, 5a. 
As is mentioned in the preceding sketch of the plants of the northern 
Trias, Hquisetum Rogerst occurs at Milford, N. J. It is quite abundant in 
the Richmond coal field and is mentioned by many writers who have refer- 
red to the plants of that region, Rogers, Brongniart, Bunbury, Schimper, 
and others. It is so fully deseribed by Professor Fontaine in his monograph 
(p. 10) that only a brief reference to it is needed here. 
Some specimens obtained at Milford, N. J., now in the collection of 
Lafayette College, which I have been permitted to examine through the 
courtesy of Prof. T. C. Porter, exhibit features which are worthy of remark. 
One of these, a compressed stem, 6° in diameter, has the joints below only 
2°™ apart, and on these are set in spiral arrangement disks which mark the 
attachment of branches or roots such as we so frequently find in some spe- 
cies of Calamites from the Coal Measures. These disks are much distorted 
and obscured, but they would seem to have been elliptical in outline, 2°™ 
long by 14° wide. 
In the same rocks and associated with stems of ELquisetum are the dis- 
coid or low-conical, radiately striate bodies which I have already referred to 
