L. Lesquereux on the Coal Formutions of North America. 215 
of Hymenophyilites are evidently related. The species belonging 
to the first have a lanceolate, bi-tripinnate frond with forked 
pinnules. All its divisions are dichotomous, linear and decur- 
ing from a creeping rhizome. The nerves are dichotomous, 
forking and thinning in ascending and the nervules simple and 
urrent in each division. Indeed, although the general ap- 
Pearance of the species belonging to both these sections is far 
different, it results only from a greater or lesser expansion of the 
limb of the frond, In the first case, there is only a narrow strip 
of it extending on each side of the nerves and following them 
1 their divisions, in the second, the derma is broader and some- 
ines fill the space between the nerves except near their extrem- 
hes. Tt appears evident that all our species related to the sec- 
ond section of Hymenophyllites have the same characters as 
@ribed-.above. All have a strong generally inflated basilar 
decurrent to the top of more or less irregular divisions; all 
t 
‘uea Gipp.) cannot belong to the ferns. 
was have apparently either a pinna 
attached on a common rachis, or a compou 
one to one 
other American species are st 
oe en re have from our coal 
i wore ‘ore. bn ‘ 
ymenophyllites giganteus Lsqx., ‘ 
Measures : Lijinenisphagllives: laceratus Lsqx., H. horsutus ait 
| x., A. fimbriatus Lsqx., H. adnascens Ll. and H., on a 
*eW species from Rhode Island, related to the Hymenophyllites 
: but with broad obtuse lobes. : 
| er reason for abandoning the genus P sag Pa i 
bat Some of the ih now under oe tion have alrea 1y 
Telerred by European authors to five aitte 
sce Aphlebi, Filicite, Fucoides, and Algacites. The two first 
