332 
Mycologia 
109. Uredo fenestrala sp. nov. 
Uredinia hypophyllous, irregularly scattered, or occasionally 
in small groups, pustular, 0.1-.25 mm. across, opening by a 
central pore becoming enlarged and irregular, subepidermal ; 
peridium hemispherical, 'delicate, cellular, the cells elongated 
more or less at the sides, nearly isodiametric above, trapezoid or 
cuboid, 10-13 ■walls evenly thin, the ostiolar cells 
unmodified ; urediniospores obovoid or ellipsoid, inclined toward 
pyriform, 16-22 by 25-36 wall cinnamon-brown, slightly paler 
below, evenly thin, 1-1.5/^, moderately echinulate, the pores in- 
distinct, apparently 2 or 3, somewhat superequatorial. 
On Euphorbiaceae : 
Phyllanthus grandifolius L., Bayamon, Feb. 19, May 
21, 1822 (type) ; Villa Alba, Jan. 4, ^2/. 
The rust on the same host has also been detected on a phanero- 
gamic specimen, collected on the island of St. Domingo, Dec. 
1909, N. Taylor 365. 
What appears to be the same rust showing only uredinia was 
collected on Phyllanthus distichus (L.) Mull.-Arg., San Juan, 
P. R., January, 1911, by E. W. D. Holway. The texture of the 
leaf is less firm in this host, and the rim of the sorus does not 
hold up sufficiently to give the crater- form appearance usually 
seen on P. grandifolius. The urediniospores are also slightly 
smaller and paler. 
The peridium in this species is most delicate and difficult to 
demonstrate from dried specimens. The usual appearance in 
free-hand sections is that of a sorus without enveloping struc- 
tures; there certainly are no paraphyses. The description of 
Uredo Phyllanthi P. Henn. from Brazil, gives the wall of the 
spore as smooth and 2-3 ix thick. The uredinia of Phakopsora 
Phyllanthi Diet., which occurs on Phyllanthus distichus in India 
and the Philippines, is said to have strongly developed, incurved 
paraphyses. The descriptions only of these two species are 
available to the writer, and they indicate decidedly unlike forms, 
both of them differing from that in the West Indies. 
{To be continued) 
