Part 6, 1921] AECIDIACEAE 421 
I. Aecia hypophyllous, few, crowded in small groups opposite the pycnia, bullate, 0.2- 
0.5 mm. across; peridium short-cylindric, white, lacerate; peridial cells rectangular, abutted 
or slightly overlapping, 10-12 by 26-35 yu, the wall colorless, the outer smooth, 1.5 u thick, the 
inner very closely verrucose, 4 x thick; aeciospores globoid or broadly ellipsoid, 13-28 by 23- 
32 w; wall colorless, 1-1.5 «4 thick, closely and finely verrucose. 
II. Uredinia hypophyllous, few, scattered, small, 0.2-0.5 mm. across, pulverulent, cinna- 
mon-brown, ruptured epidermis not conspicuous; urediniospores broadly ellipsoid or obovate, 
23-26 by 26-32 u; wall pale cinnamon-brown, 1-1.5 u thick, moderately echinulate, the pores 2 
or 3, equatorial. 
III. Telia hypophyllous, few, scattered, small, 0.2-0.5 mm. across, early naked, chestnut- 
brown, ruptured epidermis not conspicuous; teliospores fusiform or oblong-fusiform, 19-26 by 
44-60 u, narrowed above and below, somewhat constricted at septum; wall cinnamon-brown, 
uniformly 1 » thick, smooth; pedicel colorless, fragile, about half length of spore. 
ON CaRDUACEAE: 
Vernonia pluvialis Gleason, Jamaica. 
TYPE LocALITy: Summit of Blue Mountain Peak, Jamaica, on Vernonia pluvialis. 
DisrrrBurion: Known only from the type locality. 
235. Dicaeoma nothum (Jackson & Holway) 
Arthur & Jackson. 
Puccinia notha Jackson & Holway; H. S. Jackson, Bot. Gaz. 65: 305. 1918. 
O. Pycnia epiphyllous, few, gregarious, inconspicuous, depressed-globoid or conic, 60-90 
by 50-90 y; ostiolar filaments short. : 
I. Aecia hypophyllous, few, gregarious on somewhat thickened spots; peridium cylindric, 
whitish, membranous, rupturing irregularly; peridial cells seen only in face view, irregularly 
polyhedral or rectangular, 18-26 by 35-48 u, the wall colorless, thin, 1-2 u, closely verrucose- 
rugose; aeciospores somewhat irregularly ellipsoid or globoid, 20-26 by 26-35 u; wall thin, 
1-1.5 y, closely verrucose, with the markings somewhat deciduous, the pores not evident. 
II. Uredinia amphigenous, few, scattered, round, very small, 0.1-0.2 mm. across, early 
naked, pulverulent, whitish, ruptured epidermis not conspicuous; urediniospores globoid or 
obovoid, 22-26 by 26-32 4; wall colorless, 1.5-3 4 thick, moderately echinulate, the pores 
obscure. 
III. Telia amphigenous, chiefly epiphyllous, scattered or gregarious, small, 0.2-0.8 mm. 
across, early naked, becoming pulverulent, blackish-brown, ruptured epidermis not conspicuous; 
teliospores broadly ellipsoid, 26-34 by 35—48 yu, rounded at both ends, slightly or not constricted 
at septum; wall chestnut-brown, 3.5—5 » thick, slightly thickened by a subhyaline umbo to 
7 w at apex and over pore of lower cell which is usually placed near pedicel, or half way be- 
tween pedicel and septum, prominently, evenly, and moderately verrucose, with acute points 
about 3-4 «4 apart; pedicel colorless, persistent, firm, 5-7 « thick, tapering and minutely verru- 
cose at lower end, once to two and a half times length of spore, often attached laterally. 
On CARDUACEAE: 
Vernonia leiocarpa DC., Guatemala. 
?Vernonia Shannoni Coult., Guatemala. 
TvPE LOCALITY: Solola, Guatemala, on Vernonia leiocarpa. 
DISTRIBUTION: Guatemala. 
236. Dicaeoma ratum (Jackson & Holway) 
Arthur & Jackson. 
Puccinia rata Jackson Holway; H.S. Jackson, Bot. Gaz. 65: 303. 1918. 
O and I. Pyenia and aecia unknown. 
Il. Uredinia amphigenous, chiefly hypophyllous, scattered, round, standing out from 
surface of leaf, small, 0.2-0.4 mm. across, early naked, becoming pulverulent, cinnamon- 
brown, ruptured epidermis not conspicuous; paraphyses abundant, peripheral, standing well 
out from substratum, incurved, clavate, 15-18 by 100-125 u, the wall colorless or very slightly 
tinted with brown, uniform, thin, 0.5-1 4; urediniospores globoid or broadly obovate, 24-29 by 
26-32 »; wall dark cinnamon-brown, 2.5-3.5 » thick, rather closely echinulate, the pores 4 or 5, 
scattered. 
