and the causes affecting its recent diminution. 65
P. coccodes, f. bacillosa, Nyl. — At the edge of Hoghill
Pond, Hainault Forest. Fertile (Hb. E. F.). I have not
anywhere seen either the type or this form.
P. fallax, Pers. — On Epping Forest and in Hainault
Forest. Fertile (Hb. E. F.). About High Beach. Fertile
(J. M. C.). Occurs also elsewhere, but usually in an im-
perfect condition.
P. lutescens, Hoffm. — On Epping Forest. Sterile (Hb.
E. F.). On an old tree, since felled, near the King's Oak.
Sterile (J. M. C.).
Phlyctis agelaea, Wallr.—On trees by the roadside beyond
the King's Oak (J. M. C.). Now extinct in that locality, but
probably to be detected elsewhere.
P. argena, Flk. — Near the King's Oak, High Beach (Hb.
E. F.). I have not seen this species in a fertile condition,
though what may be the sterile thallus occurs in various parts.
Tribe —Thelotremei.
Thelotrema lepadinum, Ach.—On hornbeam at Waltham-
stow (Hb. E. F. s. n. Lichen inclusus). At High Beach, and
Wintry Wood, near Epping (J. M. C). Apparently a rare
lichen in the Forest.
Urceolaria scruposa, Ach. — On walls of garden, Hoe
Street, Walthamstow (Hb. E. F.). On mortar of walls at
Epping (J. M. C.). I have not recently seen this species.
Tribe—Lecideei.
a. Biatora.
Lecidea lightfootii, Sm. — On a tree at Walthamstow
(E. F.), fide Forster's MS. notes. There is, however, no
specimen in his Hb., and I have nowhere seen it in the
Forest.
L. quernea, Dcks. — On an oak in the Forest (Hb. E. F.).
Also formerly at High Beach (J. M. C). I have recently
observed only the sterile thallus, and that but sparingly.
L. coarctata, Ach.—On bricks in the Forest, near Salter's
Buildings (Hb. E.F.). Now apparently extinct in the Forest.
L. decolorans, Flk. — On the ground amongst heaths in
Lodge Road. Very rare, and seen only in one spot (J. M. C).
F