^Devonian Plants from Ohio. 55 



Tangential Section. — Medullary* rays in single and double-width 

 bands; simple bands have from one to twenty superimposed cells : 

 double width bands have from six to thirty cells ; nearly all the 

 cells of the medullary rays contain globules of resinous matter. 



Sphenophyllum vetustum, n sp. 

 Plate VI., fig 1. 



Stem much branched, tiexuous, leaves crowded in irregular 

 whorls, divergent, wedge-shaped, strongly nerved ; nerves dichoto- 

 mously forked; margins apparently fimbriate. 



The imperfect state of preservation of the only specimen of this 

 plant yet known makes it impossible to give a detailed and satis- 

 factory description of it. The geological horizon of the rock from 

 which it was obtained is, however, so low that all the plants found 

 in it acquire special interest. The general aspect of the plant is 

 that of the submerged branches of Sphenophyllum erosum, Brongt. . 

 in which the leaves are dissected and much crowded on the 

 branches, but this bush-like appearance may be due to the skel- 

 etonizing of the leaves by maceration. The specimen before me, 

 which consists of an impression and counterpart, was obtained by 

 Prof. E T. Nelson from the upper part of the Corniferous lime- 

 stone, at Delaware, Ohio. As this is a marine deposit, abounding 

 in shells and the remains of fishes, the conclusion that it is a land 

 plant would be open to suspicion, if it were not evidently very 

 unlike any known sea-weeds, and had not numerous other land 

 plants been found with it. The stem is replaced by coaly matter 

 which in its quantity proves that it had a woody structure, while 

 sea-weeds, composed of cellular tissue only, have entirely disap- 

 peared, leaving nothing but an imprint with perhaps a stain of 

 carbon. 



We may then be quite sure that this is a land plant, and it resem- 

 bles so closely Sphenophyllum, that I feel justified in referring it to 

 that genus, which appears in the first group of land plants of which 

 we have any knowledge. 



As I have said with reference to the tree ferns found in the same 

 locality with this and at Sandusky, there is a strong probability 

 that this plant floated off from neighboring land occupying the 

 position of the Cincinnati arch. 



The type specimen is in the cabinet of Wesleyan University, 

 Delaware. Ohio. 



