126 
Mycologia 
tures are needed before any final conclusion can be reached. We 
are indebted to Messrs. Hedgcock and Meinecke for furnishing 
for our studies portions of their authentic material. 
The structural differences between these two forms, which are 
partly one of length of the peridium, may not be so essential as 
might appear at first thought. Ordinary aecia, which usually ap- 
pear short and cupulate, oftentimes have been known to grow out 
into a cylindrical shape many times as long as broad. The pres- 
ence of the distinct filaments seems very remarkable in Peck’s 
type and has never been duplicated in any specimens examined 
by us although the attenuate projections from floor and dome of 
the aecium as previously pointed out under Per. stalactiforme are 
homologous. It may be possible that none of the specimens listed 
under this species, except the type, should be referred to Per. 
filamentosum and that this name should be retained for specimens 
which bear its characters in an unmistakable manner. An 
argument against such a disposition, however, is the fact that 
there is no known species of Cronartium which might be a telial 
connection, in other words, if we keep these two forms separate 
we have more forms of Peridermium than are required to ac- 
count for the known telial stages. 
13. Peridermium pyriforme Peck, Bull. Torrey Club 6: 13. 
1875 
Aecidium pyriforme Peck, Farl. Bibl. Index 1 : 78. 1905. 
Peridermium Betheli Hedg. & Long, Phytopath. 3: 251. 1913. 
0. Pycnia unknown. 
1. Aecia appearing on the branches or often on the trunks, with 
no or only slight fusiform enlargements, scattered and usually dis- 
tinct, oval or irregular in outline, sometimes elongate, 1-3 by 1-6 
mm. or larger by becoming confluent, peridium not much exserted 
above the roughened bark, rupturing along the sides and falling 
away; aeciospores pyriform, oblong-pyriform, or obovate, 19- 
24 x 32-66 /a, usually acuminate below ; wall 2-3 /i thick, rather 
finely and closely verrucose with low papillae; contents orange- 
yellow when fresh. 
On Pirtus Banksiana Lamb. ( P . divaricata Auct.), Wisconsin 
(Douglas County, July 1907, Davis). 
On Pinus Murray ana Oreg. Com., Colorado (Gatos, July 23, 
