IN THE LOWER OLD BED SANDSTONE OF SCOTLAND. 219
from which the leaves have disappeared. The leaf is not clean-cut on the upper margin, but has something like a cicatrix scar.
" As to their name, it is probably the larger stem of a plant like Dawson's Psilophyton princeps, with which it agrees in structure &c. No doubt his Arthrostigma and Cyclostigma are the same things ; but we yet want light as to the true nature of these Devonian Ly- copods."
The preceding facts comprise all the in formation we at present possess bearing on these interesting fragments. Beyond the probable dichotomous method of branching, we are unacquainted with any of the broader characters ; neither do we know any thing of the fructi- fication. The plentiful manner in which the matrix is traversed, gives rise to the hope that the discovery of more perfect specimens is only a matter of time and careful search. Under these circumstances we content ourselves with appending a short provisional description under the name of
