1877. ] 169 {Lesquereux. 
5 was communicated by Mr. C. B. Dyer. It is upon the surface of a stone 
exposed for a long time to atmospheric influence. All the specimens are 
from around Cincinnati, in connection with invertebrate animal fossils of 
the Cincinnati Group. 
Plants of the same kind have been found many times already it seems ; 
for Professor Mickleborough informs me that another specimen discovered 
within the clay, somewhat obscure, and apparently like the one of our 
fig. 8, was washed and rubbed in order to expose the ieaflets more dis- 
tinctly, and in that way the leaves were nearly totally effaced. Another 
offered for sale was from description like that of fig. 5. Still others have 
been mentioned to me. They have been considered by some collectors as 
the work of insects; by others as fucoidal or coralline productions, like 
Oldhamia ; and by others as specimens of the vegetation of the Carbonif- 
erous transported by drift. All these suppositions are contradicted by the 
fragments found imbedded in the clay or attached to pieces of hardened 
clay of the same compound as the Cincinnati blue marl, and still more by 
the described characters of these plants. 
Prorostiama, Lesqx. 
This Generic name is provisionally admitted for the description of frag- 
ments of stems whose relation to species of Sigillaria and other types of 
vegetables of the Devonian and the Carboniferous is surmised from the 
rhomboidal form of the scars or bolsters marked upon their bark. This 
form is very commonly seen upon plants of this kind. It characterizes in 
its multiple more or less definite transformations, the impressions of the 
outlines of the points of attachments of simple leaves to stems, branches or 
trunks of trees of the old formations. Therefore, it would not be surpris- 
ing to find it already traced upon Silurian woody stems or branches. The 
reference of those original marks, as long as they are not defined by the 
vascular scars in the middle, is not possible This is implied by the name 
under which the remains are described. 
PROTOSTIGMA SIGILLARIOIDES, sp. nov. 
Pl. I. fig. 7-8. 
Branches or stems cylindrical, scarcely flattened by compression ; sur- 
face marked by rhomboidal cicatrices, enlarged on the sides, contiguous and 
in spiral order, with indistinct impressions of oval vascular scars in the 
middle. 
I refer to this specific form three specimens, two of which are figured 
here. The fragment of branch, fig. 7, is represented in its natural size. It 
is slightly obliquely compressed, and thus, the lateral bolsters are some- 
what disfigured on the two sides, and displaced from their normal position. 
But on the face as seen in fig. 7 and 7 a, the scars are preserved in their 
original arrangement. Even the central vascular points are distinctly seen 
in the middle of some of the bolsters, though the whole impression is of 
course somewhat obliterated by erosion of the mould, or by decomposition 
PROC. AMER. PHILOS. soc. vil. 100. v. PRINTED NOV. 8, 1877. 
