220 Prof. G. de Notaris on the Tribe Spheriacez. 
the genus Spheria, proposing the genera Diplodia, Ostropa, Cu- 
curbitaria, Cryptospheria, Valsa and Hypocrea, which econye- 
niently limited according to the characters of fructification com- 
mon to the greater number of the respective species, and selected 
from the heterogeneous materials which they everywhere con- 
tain, ought without doubt im some measure to be adopted, 
although for the most part founded on the appearance of the 
stroma, perithecia and nucleus, characters comparatively of small 
value. 
I comprehend among the Pyrenomycetes Spheriacee, those 
species only in which we meet with truly ascigerous conceptacula 
or perithecia, whether spheroidal, lentiform, conical, oval ; whe- 
ther obtuse or acute, or finally produced into a kind of eylin- 
drical neck, angular or compressed, isolated or gregarious, or 
collected together in a stroma of varied form ; opening by means 
of a vertical pore, sometimes scarcely visible or gaping im conse- 
quence of the thinness of the exterior coat, which yields readily 
to the shock of the sporidia bursting forth from the asci when 
arrived at maturity, or of the asci themselves separated from the 
walls of the perithecia, or in short by means of an irregular 
fissure. 
The limits indeed within which the celebrated Corda has cir- 
cumscribed the tribe or family of the Spheriacee, in his immense 
iconographical work on the family of Fungi (Icones Fungorum, 
vol. v. p. 31), might be adopted for the present, had he not as lL 
believe comprised in it genera which do not properly belong to it, 
and for the most part defined too loosely. 
In the Spheriacee we have to consider the stroma, the peri- 
thecium, its texture, the mode in which it opens, the nucleus, the 
asci, the paraphyses and the sporidia. 
The stroma, on which the fundamental divisions of Fries are 
based, furnishes characters of some importance in the greater part 
of compound Spherie, which, besides serving as a receptacle for 
the perithecia, presents a determined form characteristic of each 
species. The stroma cannot properly be compared to the thallus 
of Lichens, because it is an integral part of the fructifymg appa- 
ratus. From the mycelium, the true equivalent of the thallus, 
-one can scarcely draw materials for the diagnosis of the genera, 
because it is always extremely difficult to follow up its develop- 
ment. Deeply invested in the substance of the matrix or con- 
fluent with it, and often evanescent in fructifying individuals, it 
cannot afford precise characters except by the help of observa- 
tions, often perhaps impracticable, and attentively followimg up 
the development before the evolution of the perithecia. In the 
simple, free, superficial or innate species, and in the Cespititie, the 
nature of the stroma appears less clear, because in some species, 
