i __ the leaves and can be teased out readily with a needle (ig. 2). 
BRIEFER ARTICLES. 
ACROSPERMUM URCEOLATUM, A NEW DISCOMYCETOUS 
PARASITE OF SELAGINELLA RUPESTRIS. 
(WITH PLATE XXIX.) 
On some material of Seaginella rupestris (Linn.) Spring. recently 
examined a small discomycetous fungus was discovered which at once 
aroused inquiry from its occurrence upon a plant so rare as a host. 
The characteristic features of the plant show it to be an Acrosper- 
mum, but there is no record of such a fungus upon Selaginella, and it 
does not correspond to any of the described species. The material on 
which it was found was collected at Taylors Falls, Minnesota, in August 
1896, and had been preserved in 80 per cent. alcohol for several 
months when it was brought into the laboratory for use and the pres- 
ence of the fungus was discovered. 
The family Acrospermacez' is of particular interest because of its 
intermediate position between the Pyrenomycetes and Discomycetes. 
In this genus especially the early stages show an intimate connection 
with the closed apothecia of the Pyrenomycetes, while the development 
of a broad ostiole in the mature forms indicates relationship with the 
open oe ascoma of the Discomycetes. 
rough such a transitional form the closed indehiscent seniecnae 
of the Erysiphe type connects with the saucerlike Peziza forms, and 
there is some doubt whether the term “apothecium” is the correct one 
to use, but with this reservation it will be employed. 
The apothecia studied appear upon the leaves of the host as soni 
_ dark bodies, the size of a pin head, and upon examination a branch of 
infected material plainly shows the presence of the parasite by the dark 
Spotted appearance of the leaves. This is due to the young apothecia 
on the inner side, but many of the larger ones protrude from between 
eee 
othe plant is epiphyllous in its habit, and no 
2 : . eeu eacees soe pose 
