FOSSIL PLANTS. 415 



which it is evidently attached, while Prof. Geinitz thinks that it is fixed in 

 small bundles to the stem, like a parasitic plant. The State Cabinet at Spring- 

 field possesses specimens of a large fern whose stem, like that described by 

 Lindley, is bordered by bundles of leaves of the same Hymenophyllites. The 

 specimen is obscure, and it is not possible to decide how they are attached to it. 



HYMENOPHYLLITES LACTUCA, Gutb. 



This species is more rarely found in our Coal Measures than its near rela- 

 tive, II. Clarkii. Lesqx. The State Cabinet has a very fine specimen of it in 

 a concretion from Mazon creek. It is distinguished from H. Clarkii by its 

 broad enlarged fronds and narrow laciniae. These fronds or rather pinnae, on 

 one side of the rachis, which are only visible in part, appear placed in a row, 

 like the alternate divisions of a fern. As the epidermis of some of these pin- 

 nae is destroyed by maceration, the veins and veinlets are distinct, an d^ are seen 

 passing in bundles from the rachis, separating more and more in curving into 

 each division, to end by a simple veinlet, ascending to the point of the acute 

 ultimate lobes. 



HYMENOPHYLLITES ARBORESCENS, Sp. nov. 



PI. xvii, fig.l . 



STEM long, (the specimen, though broken, shows more than 

 one foot of it,) straight, about one inch broad at its lower end, 

 two-thirds of an inch at its upper part, marked in its length 

 by obscure lines apparently formed by bundles of veiiilets and 

 alternately divided in thick oblique branches, more or less 

 regularly and deeply lobate ; lobes alternate, simple and linear 

 elongated, or bi-trifid, of various lengths and obtusely pointed. 



The divisions of this plant are rather dichotomous, like those of species of 

 Lycopodiacea, than pinnatifid like those of ferns. They are merely a continu- 

 ation of a main axis thrown out in various directions. The substance appears 

 to have been a compound of cellular soft tissue, intermingled with bundles of 

 continuous vessels, forming veins or veinlets, and, by mere separation, ascend- 

 ing to the last divisions of the frond. There is no trace of branching of veins, 



