South African Perisporiales. 
717 
Dimerosporium Acokantherae P. Henn. 
Sydow has determined Wood's Nos. 6450 and 6461 as D. Acokantherae 
P. Henn. ; the fungus on the leaves of Acohanthera spectahilis under these 
numbers is not a Dimerosjjormm, it has the shield-shaped perithecia of the 
Microthyriaceae. The spores are immature. 
Species Excluclendae. 
Dimerosporium MacOvMnianum Thuem. = Dimeritim MacOwaniayium 
(Thuem.). 
Dimerosporium Psilostomatis Thuem. = JDimerium Psilostomatis (Thuem). 
Dimerosporium verrucicolum Wint. = Aster odothis Solaris (W'mi.)H]iQ\^^. 
DiMERIELLA. 
Mycelium poorly developed. Perithecia sub-globose, astomous, setulose. 
Asci 8-spored. Spores 2-celled hyaline. 
JDimeriella annulata, Syd. 
Ann. Myc. x (1912), p. 36. 
Mycelium amphigenous, very slender and slightly developed, but distinctly 
developed in concentric rings and forming spots |-1 cm. diam. Hyphae 
slender, not much branched, light brown, and bearing sarciniform conidia. 
Oonidia transversely 3-septate and longitudinally 1-septate, light brown. 
12-17 X 7-10 /X. Perithecia superficial, globose, astomous, black, under 
microscope fuliginous, 50-100 /x diam., bearing a few rigid black-brown 
setae, 50-120 /x long and 4 /x thick. Asci sub-globose or ovate 25-30 X 
20-25 /X, 8-spored. Spores ellipsoid, rounded at both ends, 1-septate and 
constricted, at first hyaline then brown, 17-24 x 8-12 /x, the loculi slightly 
unequal. 
On leaves of Gymriosporia sp., Bandolier Kop, Zoutpansberg Dist., 
11/8/11, E. M. Doidge (1832). 
Dimeriella claviseta Doidge n. sp. 
Epiphyllous, forming thin, spreading spots of varying size ; mycelium 
much-branched, fuscous, formed of radiating flexuose hyphae 3-3*5 /x thick. 
Perithecia superficial, scattered or sub- gregarious, sub-hemispherical, black, 
carbonaceous, with a false ostiole, 90-115 /x diam., bearing near the base 
9-15 setae. Setae club-shaped, 15-55 /x long, 3-5-7 /x thick at the base, 
septate and often constricted at septa, becoming broader above ; apex 
truncated and variously lobed, frequently 2-lobed, lobes also truncated. Asci 
numerous, paraphysate, 8-spored, sessile, clavate-cylindrical, rounded and 
not thickened at the apex, 40-50 x 18-20 /x. Paraphyses simple, filiform, 
longer than the asci. Spores conglobate or distichous, hyaline, 1-septate, 
49 
