420 
PALAEONTOLOGY OF ILLINOIS. 
of this plant. They are placed without any kind of order, crossing each other 
in various directions, as if they had been strewn on the stone, and therefore 
the kind of divisions marked in the figure, and abnormal, if this plant belongs 
to a fern, may be merely caused by the casual superposition of two branches 
joined by their bases. The form of the leaves, their peculiar position along 
the stem on the, same side of it, resembling the divisions or lobes of some ferns, 
and their mode of attachment, indicate the close relationship of this plant to 
those published by Prof. Brongniart as Pacliypteris. In some of our branch- 
lets the basilar prolongation of the pinnules along the rachis? of the pinnae 
has become detached by compression, and they appear in that way as bearing, 
at the base, a long, linear auricle. The pinnules are a little enlarged to the 
very obtuse point, as seen in fig. 8, enlarged four times, and in fig. 7, enlarged 
twice. 
On shale, from Morris, collected by Mr. Jos. Even. 
LEAVES OF UNCERTAIN OR UNKNOWN AFFINITY. 
Genus CORDAITES, Ung. 
Ill. Geol. Rep., vol. ii, p. 443. 
CORDAITES ANGUSTIFOLIA, Sp. 110V. 
The roof of the main coal at Duquoin and St. Johns is in 
places covered to a thickness of six inches to one foot, with 
remains of flat, narrowly equally striate, long linear leaves, 
one to one and a-half inches broad, which, as yet, have not 
been found in connection with any stem. 
From their linear form and from the narrow striae marking their surface, I 
refer these leaves to the genus Cordaites, Ung., being unable to see the char¬ 
acters which separate these ribbon-like leaves into two genera, viz. Cordaites 
and Noeggerathia. 
