1918] STEVENS—MELIOLA PARASITES 237 
fungus parasitic upon it; and, as just stated, that the stilboid conid- 
ial forms belong to the genus Arthrobotryum. ‘That this conclu- 
sion has also been reached by Sypow’ is indicated by his description 
of A. caudatum on Meliola in 1909. The type specimen of A. cau- 
datum, loaned to me by Sypow, clearly is cogeneric with the various 
forms on Meliola which have heretofore been called Podosporium. 
I present the following synopsis of the Porto Rican forms of this 
genus: 
Key TO Porto RICAN SPECIES OF Arthrobotryum 
Coremia incasing the Meliola setae. ............-..000005- A. dieffenbachiae 
Coremia not incasing the Meliola set 
Vegetative mycelium closely ean the Meliola mycelium. . A. glabroides 
Vegetative mycelium not closely sheathing the Meliola mycelium 
A. 
Conidia long, elliptical, with no distinct beak cell......... penicillium 
Conidia with distinct beak cell, basal cell, and two central ns 
. caudatum 
Arthrobotryum dieffenbachiae, sp. nov. (fig. 4).—Mycelium 
inconspicuous, scant, fine, pale, tufted around the bases of the 
coremia. Coremia often growing incasing the setae of the host, 
yellow, stalks 17-31 yw thick; total length 470-630 4; apical por- 
tion either broadened into a fan-shaped brush or very narrow with 
lateral conidia; sporiferous part about 150m long. Conidia 
3-Septate, pale straw colored, pointed at each end, apical cell longer 
than basal cell, 35-38 x 3-4 uw. 
On Meliola dieffenbachiae Stev. on Dieffenbachia sequina, no. 8077 (type), 
Dos Bocas below Utuado 
This species is the only one recorded which utilizes the setae of its host as 
supports for the coremia. The young coremia are somewhat transparent, and 
in them the supporting setae with their characteristically branched apices may 
be seen incased. 
Arthrobotryum glabroides, sp. nov. (figs. 1—3).—Mycelium 
forming a loose network on the leaf surface but a close sheath over 
the Meliola mycelium, so dense as to partially obscure the hypho- 
podia, very fine, about 1 to 1.5 4. Coremia straight, rigid, black, 
stalk about 24 u thick, head 8 5 w wide and 85 u long, top-shaped. 
Total length of coremia 5 50 uw. Conidia narrowly elliptical, acute 
* Sypow in De Wipeman’s, Emit pk, Fl. Bas et Moy., Congo pl. III, fasc. 1, 
