416 
PALAEONTOLOGY OF ILLINOIS. 
but merely of divisions of fascicles of vascular tissue. The species, in its gen¬ 
eral form, resembles Schizopteris pachyrachis, a species of the Keuper. 
Found at Morris on a large piece of shale, and kindly presented by Mr. Jos. 
Even. 
IIymenophyllites Clarkii, Lesqx. ' h Iti ■/; 
PI. xvi, fig. 1 and 2. 
The description of this species is given in vol. ii of this Report, p. 438, pi. 
xxxix, fig. 7, from a small specimen. It is abundantly found in the concre¬ 
tions of Mazon creek, and, though very variable, preserves the characters 
which separate it from II. Gutbierianus, Grein., viz : its broad, round, or very 
obtuse divisions, and the great thickness of the leaves, which were evidently 
hard and coriaceous; for they are not flattened on the stone as in II. Gutbieri¬ 
anus, but enter it, and mark on it a deep impression, as a hard body only can 
do. Of the two remarkable specimens figured here,'the first appears to repre¬ 
sent a plant with a long twisted or climbing stem. The principal axis is round, 
grooved, and has its surface roughened, and marked with points or scars, as if 
it had been covered by hairs or scales. As the stem of the second specimen, 
which seems to represent a young plant evidently of the same species, is 
smooth, these points may be the scars of rootlets or suckers, serving as adhe¬ 
sive agents to help the climbing process. The young plant, fig. 2, has a short 
stem already curved or twisting, and at its base, some filaments resembling 
rootlets. It would, therefore, be rational to conclude, from these specimens, 
that the plants which they represent were attached to the ground or to some 
soft substance, like decayed wood, by rootlets, but were at the same time 
climbing plants. This would explain the position of II. adnascens upon the 
broad rachis of some ferns. 
Hymenophyllites Gutbierianus, Ung. Gen. and Spec., p. 132. 
twL f t /if G p , (f] 4.\ L+!>.Lf 
The true species, as figured by Greinitz, is in the State Cabinet, in speci¬ 
mens from Colchester, found by Prof. A. II. Worthen. 
