336 On the so-called Land Plants from the Lower Silurian of Ohio. 



refers tliem to tlie geuus Slglllaria ; and this case is cited as the first 

 instance where plants so highly organized have been met with in Lower 

 Silurian rocks. Through the kindness of the Rev. H. Hertzer, to 

 whom the specimens in question belong, they had been in my possession 

 some time before the publication of Mr. Lesquereux's notice, and I had 

 examined them with some care, for the purpose of determining, if pos- 

 sible, their botanical relations. I had also made careful drawings of 

 them, of which copies are herewith submitted. As the result of 

 my examination, I am compelled to say that I fail to find, either in 

 the external characters or internal structure of these specimens, any 

 satisfactory evidence that they represent land plants ; still less, that they 

 form species of the genus Siglllaria. Their external markings are 

 foirly represented in the accompanying figures [here omitted because 

 not necessary to a full comprehension of the subject], and they exhibit 

 no internal organic structure whatever. They are simply casts in earthy 

 limestone, without carbonaceous matter or any traces of woody tissue. 



The smaller specimen is a discoid section of a cylindrical trunk, of 

 which the external surface is very smooth, but is marked by a 

 reticulation not unlike that of one section of the genus Sigillaria. I 

 did not discover, however, any dots or tubercles in the center of the 

 meshes, such as are referred to by Mr. Lesquereux, and which, were 

 they present, might be supposed to represent the place of the nutrient 

 vessels of the leaves. Taken by itself, I should say that this specimen 

 might be a sponge, or some other low form of marine life, quite as well 

 as a Sigillaria. Since it is so small and forms so little of the original 

 organism, I think it would be unsafe to make it the base of any general 

 and important conclusion. 



The larger specimen is represented, like the other, of natural size. 

 This is also a cast of a nearly cylindrical trunk, of which the external 

 surface is roughened by irregularly disposed and unequally sized 

 lenticular prominences. These resemble, in a rude way, the leaf scars 

 borne by the trunks of some lycopodiaceous or cj'cadaceous plants, but 

 they do not exhibit the spiral arrangement, nor the details of structure 

 which the leaf-scars of such plants almost uniformly retain in the fossil 

 state. In the interior of this trunk are seen a few of the irregularly 

 scattered points of carbonaceous matter, but they are not continuous 

 fibers, and to my eye show no traces of cell structure. 



Taking all the characters of these interesting fossils into considera- 

 tion, I am disposed to regard them as casts of the stems of fucoids. Had 

 they been land plants, they would almost certainly exhibit more 

 distinctness and regularity of surface marking, some coating of carbon- 

 aceous matter, and some traces of organic structure. A large number 



