198 Salmon . — On Oidiopsis taurica (Ldv.), 
conidium in this variety, which I have called angulata , is very closely 
similar to that found in the variety lanuginosa of O. taurica , as may be seen 
by comparing Figs. 11-15, 30-33 ' m Ph XIII, XIV with those given in my 
recent paper on Phyllactinia ( 5 , PI. XIV). Moreover, there is a similarity 
shown by the two varieties in their distribution and promiscuous choice of 
hosts, — P. corylea , var. angulata , being found in the United States on 
Quercus , Castanea , Fagus , and Ulmus , in South America on Adesmia , 
and in Europe on Hippophae ; and < 9 . taurica , var. lanuginosa , being found 
in the United States on Mimulus , in Europe on Dane us and Chondrilla , 
and in Africa on Foenicidum. Further, as pointed out above (p. 195), the two 
genera have several other common characters. 
The conidium of 0 . taiirica may be quite smooth or (especially when 
old) rough with protuberances due to the breaking-up of the epispore ; 
in some cases — as, e. g., in specimens on Phlomis pungens , Odontospermum 
aquatiemn , Vicia angustifolia , Clematis songarica , Cistus monspeliensis , 
Astragalus sp. — the epispore breaks up almost completely into flakes. 
< 9 . taurica is sometimes attacked in its conidial stage by the parasitic 
fungus Ampelomyces quisq 7 ialis — a fact which Prof. G. Scalia has inde- 
pendently observed. This parasite, whose life-history was first worked 
out by De Bary (12), causes a transformation of the conidium, or cell 
of the conidiophore, attacked, which turns a dark brown (see Fig. 8). 
The synonymy of the present species, and its distribution and host- 
plants — additional to that given in my Monograph ( 2 ) and ‘ Supplementary 
Notes ’ ( 3 ) — are as follows : — 
Oidiopsis taurica (Ldv.). 
Oidium Flaplophylli P. Magn., in Verh. k. k. zool.-bot. Gesell. Wien, 1 ., 445 
(1900). 
0 . gigasporum Scalia, in Rendiconti del Congresso hot. Palermo, 9 (1902). 
Oidiopsis sicula Scalia, in Rendiconti del Congresso bot. Palermo, 10 (1902) ; 
Scalia, in L’Agric. Calabro-Siculo, xxvii, 396 (1902). 
Erysiphe AsterisciV. Magn., in Hedwigia, xliv, 16, Taf. II (1904). 
E. taurica Ldv., var. Duriaei (L£v.), R. Maire, in Bull. Soc. Sci. Nancy, ser. 3, 
tom. vi, 6 (1905). 
E. taurica Lev., var. Zygophylli, R. Maire, 1 . c., pi. ii (1905). 
Distrib. — A aV Europe : Sicily, Corsica, Montenegro ; Africa: Canary Islands, 
Teneriffe, Santa Cruz. 
Posts. — Add: Asclepias curassavica (conidial stage only), Ballota rupestris , 
Centaurea dissecta subsp. Parlatoris , Cistus monspeliensis (conidial stage only), 
Cousinia concinna , Chrozophora tine tor ia, Epilobium hirsutum , Onobrychis viciae/olia 
(conidial stage only), Psoralea bituminosa , Rut a Buxbaumii (conidial stage only), 
Verbascum bithynicum , V. Thapsus. 
var. lanuginosa (Fckl.) 
Erysiphe lanuginosa Fckl., in Bot. Zeit., 27 (1871). 
