South African Perisjporiales. 
719 
strongly constricted at the septum, upper part 10*5 /x thick, lower part 13 
thick, the whole spore 2b fx ong, somewhat acuteat each end, fuscous. 
On leaves of Celastrus huxifolius, Somerset East, July, 1876, P. MacOwan 
(MacOwan 1250). 
Dimerium Psilostomatis (Thuem.) Sacc. 
Sacc. Syll. Fung, xvii, p. 537. 
{Dimerosporium Psilostomatis, Sacc. Syll. Fung, i, p. 54.) 
Hypophyllous, rarely epiphyllous, forming effuse, black, very thin, more 
or less orbicular spots. Hyphae slender, branching obscurely septate, buffy 
olive (E. XXX) 4-5 fx thick, with fairly umerous unicellular, alternate or 
unilateral, ovate hyphopodia about 7 x 3*5 /x. Perithecia small, sub-globose, 
carbonaceous, 80-85 /x diam., surrounded by numerous radiating hyphae 
darker in colour than the ordinary hyphae and without hyphopodia. Asci 
broadly clavate, wall thickened at the apex, narrowed at the base, often 
slightly curved, 45 x 24-26 /x, 8-spored. Spores in three rows, narrow 
elliptical, 1- septate, constricted at the septum with equal loculi, rounded at 
both ends, 16-20 x 6-9 /x, fuscous. Paraphyses none. 
On leaves of Plectronia ciliata, Somerset East, December, 1876, P. 
MacOwan (MacOwan 1291). 
On leaves of Plectronia Guenzii, Woodbush, Zoutpansberg Dist., 3/8/11, 
E. M. Doidge (1744) ; Claridge, Natal, 31/5/15, E. M. Doidge (8991). 
Dimerium Gymnosporiae (P. Henn.) Syd. 
Syd. Ann. Myc. vii (1909), p. 546. 
(Dimerosporium Gymnosporiae (P. Henn). Sacc. Syll. Fung, xvi, 
p. 408.) 
Mycelium epiphyllous or amphigenous, sub-crustaceous, radiating, effuse, 
black. Hyphae branched, septate, sinuous, with a few small unicellular 
hyphopodia, 7-11 /x thick. Perithecia gregarious, membranaceous-suboar- 
bonaceous, globulose, rugulose, about 90-110 /x diam. ; asci ovoid, rounded 
at the apex, subtunicated, attenuated at the base, sometimes substipitate 
35-50 x 30-45 /x, 8-spored, paraphysate. Spores conglobate, ovoid 1 -septate, 
constricted, fuscous, 18-24 x 10-13 /x. 
On leaves of Gymnosporia sp. Umbelusi, Portuguese East Africa. C. W. 
Howard (523). 
Phaeodimeriella. 
Mycelium well developed, black, effuse. Perithecia globose, setulose. 
Asci 8-spored. Spores 2-celled, fuscous. 
Phaeodimeriella capensis Doidge n. sp. 
Hypophyllous or amphigenous, forming effuse, radiating, carbonaceous 
colonies 3-5 mm. diam. Hyphae radiating, 6-7 /x thick, with unicellular 
sub-opposite or alternate hyphopodia 8-12 x 6-7 /x, and opposite branches. 
