ON ERYSIPHE POLYCELETA. 
77 
“ Uncinula polychceta, B. & C. — Peritheeiis sparsis ; appendi- 
cibus multis. On leaves of Celtis occidentalis. Car., No. 
5619. Perithecia scattered; appendages about 28, If longer 
than the diameter of the perithecia, hyaline.” — “ Grev.,” Yol. 
iv., p. 159. 
Hypophyllous, mycelium very scanty, not forming spots ; peri- 
thecia scattered, usually not more than two or three on a leaf, 150- 
200 /x diam., appendages 25-28, simple, colourless, very slender, 
about 300 x 2-3 p. Apices strongly involute, not at all incrassated ; 
asci about 25, cylindrico-clavate, tetrasporous ; spores colourless, 
simple, elliptic-oblong, 20 X 10 pi. (Type in Herb. Berk., Kew, No. 
10588.) 
The fact of both species being met with on leaves of Celtis and 
both having the same specific name has apparently led to the idea 
that the two species are identical, and the difficulty is not lessened 
by the species described as Krysiphe polychceta, B. and C., being 
issued in Kavenel’s Fung. Car. Exs. iv., No. 68, as Uncinula poly- 
chceta, B. & C., which appears, and with reason, to have been 
accepted as the species described by Berkeley under the last name, 
which is not the case. In “ Michelia,” ii., p. 373, Saccardo estab- 
lished a new genus, Pleochceta, from specimens collected by 
Spegazzini at Buenos Ayres, and described by the latter as 
Uncinula Lyncldi, Speg., Fung. Arg. Pug. ii., p. 17. These 
specimens were considered to be identical with the Uncinula poly- 
chceta, B. & C., as published by Berkeley, Erysiphe polychceta, 
B. & C., being given as a synonym, and the whole included under 
the name of Pleochceta Cuvtisii, Sacc. and Speg. The genus 
Pleochceta is kept up by Saccardo in the “ Sylloge,” Yol. i., p. 9, 
with the following remarks after the generic diagnosis : — “ Setis 
creberrimis, rectis, contextu perithecii subcoriaceo, ascis teretius- 
culis, etc., ab Erysiphe et Uncinula dignoscitur.” In the “ Journal 
of Mycology,” 1886, p. 43, Ellis shows that Spegazzini’s South 
American specimens are identical with Uncinula polychceta, B. & 
C. , of Ravenehs Fung. Carol. Exs. iv., No. 68 (= Erysiphe poly- 
chceta, B. & C., “Grev.,” Yol. iv., p. 159). Ellis endeavoured to 
reconcile the specimens in Bavenel’s Exs. quoted above with the 
description of Uncinula polychceta, B. & C., as follows : — “ Possibly 
the statement that the number of appendages is ‘ about 28 ’ is a 
typographical error for 4 about 228/ which would be nearer the 
actual number.” 
In his Additamenta to the first four volumes of the “ Sylloge,” 
Saccardo adds considerably to the confusion by still keeping up 
the genus Pleochceta, and giving a revised diagnosis of P . Curtisii, 
Sacc. and Speg., the only species in the genus, which is a transla- 
tion of the one given by Ellis in the 44 Journal of Mycology,” as 
quoted above, and is as follows : — “Appendicibus numerosis circ. 
200, hyalinis, continuis, apice attenuatis, et incurvatis ornata.” It 
is generally admitted that in the group of Fungi under considera- 
tion the perithecial appendages constitute an important factor in 
