418 PALEONTOLOGY 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 Hymenophyllites 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 HymenopJiyllites or merely some disconnected part 

 of a Lycopodiacceous plant. 



In a concretion from Mazon creek, collected by Mr. S. S. Strong. 



3. SCHIZOPTERIS. 



HYMENOPHYLLITES MOLLIS, Sp. hov. 



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 

 taking various forms; the laciniae 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 laeiniie, 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 lacinias seem to be attached or to grow upon one 

 another like the subdivisions of a kind of FUIKJUS. Fig. 6 represents a group 

 or a heap of these filaments which appear attached and growing upon each 



