North American species of Mycena.

GLUTINIPES: CAESPITOSAE

417

entire, white, unchanging; spores ellipsoid, smooth, hyaline, 1-guttulate, 5-6 X 3-4 g; cystidia subcylindric, smooth, hyaline, projecting 15-30 X 15 y,, occupying the entire edge of the gill; stipe smooth,
white, glabrous, viscid, ridged at the apex, 1-3 X 0.1-0.2 cm.
"Type collected by West and Murrill on a hardwood log in Planera
Hammock, eleven miles northwest of Gainesville, Fla., July 20, 1938
(F 18363). Also collected at the same place by West, Arnold and
Murrill on an oak log, July 27, 1938 (F 17910). Evidently near P.
epipterygius (Scop.) Murrill but having a shorter stem and smaller
spores.
Through the kindness of Dr. Murrill I have been able to examine
a part of the type. The spores, which in my mounts measured 5-7
X 3.5-4,u, were smooth, ellipsoid, and not distinctly amyloid. This
last character is very important in this group since in most species the
spores are strongly amyloid. The basidia are short and broad, 16-18
X 7-9 I, and four-spored. Pleurocystidia were not seen, but the
cheilocystidia, as Murrill pointed out, form a sterile band along the
edge and are very conspicuous. They measure 28-42 X 10-2,5,
and when young are saccate to subventricose or broadest at the base.
The walls are delicate and collapse readily. In older specimens the
apex frequently becomes drawn out to a point. The gill edge is only
slightly gelatinous beneath the cystidia and does not fan out in
mounts of sections, as it does in many other species. The subhymenium is gelatinous. The central strand of the gill trama is floccose and
vinaceous red in iodine. The pileus trama is made up of a gelatinous
pellicle, which in sections of revived material occupies three fourths
of the thickness of the cap. The floccose portion, which becomes
vinaceous red in iodine, is thus reduced to a narrow band. A gelatinous outer layer covers the stipe. In the youngest specimen examined large caulocystidia were observed over the surface. These
measured 26-48 X 10-15 g and were clavate to subeylindric. They
collapsed readily and were difficult to find on the oldest fruiting body.
Their presence no doubt caused the stipe to be pruinose at first, and
may account for the ridges Murrill observed at the apex. The ridges
were not distinct in the dried specimens. The striations of the pileus
appear to be of the plicate type as found in some dark-spored agarics.
They extend to the disc in dried material and form a very striking
macroscopic character.
Although this species keys out near M. euspeirea and M. hondurensis, it cannot be considered closely related to them. The iodine