202 REV. M. J. BERKELEY 
to be seen satisfactorily in unexpanded specimens. Stem 
21 inches high, obese below, about + an inch thick at the 
point where the volva becomes free, soft and elastic, with the 
central fibres paler and less compact, composed of rather 
flaccid filaments, mixed with more slender filaments whose 
walls do not collapse, attenuated upwards, and then more or 
less expanded, either clothed above entirely by the hymenium, 
or continued into the very thin hymenophore, and connected 
with the hymenium on either side above the expansion. 
Pileus or hymenophore 2-3 inches broad, subhemispherical 
or ovate, unequal, clothed permanently with the volva, smooth, 
white, areolate, when dry, giving off, as well as the top g 
the stem, more or less numerous plates, continued from its 
substance, which ramify and form a spongy crumb-like | 
hymenium, which is perfectly free below. Walls of the 
cells clothed with yellow-brown, lemon-shaped sporidia, 
about —.— of an inch in diameter, attached by a short 
peduncle, and containing a large globose nucleus. The | 
apiculus at the top of the sporidia is seen only in certain 
positions. In one specimen the volva is torn off regularly — 
at the base, and remains partially attached to the edge - 
of the pileus within its cavity, under the form of a dis- 
tinct ring. M. Kunze, in his letter on the subject, informs 
me that he saw no trace of a volva in his specimens. But 
it is clear from his admirable sketch, that the stem we 
already elongated, and then no clear vestiges of the volva — 
remain below. The walls of the cells are scarcely powdery, | 
but coated with sporidia, exactly as in Hymenangium, to 
which genus Rhizopogon albus of Eng. Fl. as far as the spe" - 
cimen found by Klotzsch is concerned is certainly referrible. z 
Bulliard’s Tuber album belongs to a totally different group» 
being entosporous and not exosporous. ee 
PorvPLociuw, n. gen. | 
Volva universalis ampla persistens. Stipes distinctus - 
non cellulosus e fibris flaccidis compositus cum hymenophor? 
confluens,  Hymenium subtus liberum gyroso-cellulosum, d 
demum in processus grossos aculeiformes foetiscens; cellularum 
