418 
6 
PALAEONTOLOGY OF ILLINOIS. 
to see the form of the leaves or divisions, which may be merely 
part of branches. On the left part of the specimen the stem 
is smooth and has the appearance of a stem of some species 
of Hymanophyllites of this section; on the other side, which 
is unhappily broken, the borders are fringed with long straight 
hairs, appearing to come out from another part of the stem. 
From this it is hardly possible tc decide if the specimen repre¬ 
sents a true HymenophyUites or merely some disconnected part 
of a Lycopodiacmous plant. 
In a concretion from Mazon creek, collected by Mr. S. S. Strong. 
§ 3. SctllZOPTERIS. 
Hymenophyllites mollis, Sp. nov. 
PI. xviii, fig. 2 to 6. 
Leaves or fronds formed of groups of thin filaments, emerg¬ 
ing from a common support, apparently parasitic, enlarging 
in growing up or by grouping together, and by compression 
s taking various forms; the lacunae or filaments are generally 
united together without distinct nervation. 
This is still one of those singular plants of the coal epoch which baffles every 
attempt at analysis, when one is trying to compare them with representatives 
of our existing vegetation. This kind of vegetable is doubtfully referable to 
this section of this genus. Fig. 2 represents a kind of tubercle, resembling a 
piece of decayed wood, with traces of an axis in its middle and irregular cavi¬ 
ties, bordered all around by a short fringe of these filaments which appear as 
growing out of it in an incipient state of vegetation. These filaments repre¬ 
sented separately, fig. 3, are like linear, thin, short, obtuse lacinim, united 
together and without nerves, or with thin parallel veinlets. In fig. 4, these 
filaments, much elongated, are separated in the middle and near the base in 
various ways, appearing to come out from a mere point and to enlarge in as¬ 
cending. In fig. 5, the point of attachment of the whole group of filaments is 
well marked, and from it, the lacinim seem to be attached or to grow upon one 
another like the subdivisions of a kind of Funi/us. Fig. 6 represents a group 
or a heap of these filaments which appear attached and growing upon each 
