Arthur and Kern : North American Peridermium 127 
1906, three miles north of Allen’s Park, June 21, 1913, Bethel) ; 
Alberta (Devil’s Lake, Banff, July 5, 1907, Holway). 
On Pinus ponderosa Dough, British Columbia ( Vernon , May, 
1913, Brittain, communicated by Fraser). 
On Pinus pungens Lamb., Pennsylvania (Charter Oak, June 2, 
1913, Orton & Adams). 
On Pinus scopulorum (Engelm.) Lemm., Colorado (three miles 
north of Allen’s Park, June 21, 1913, Bethel; South Dakota 
(Rockerville, June 1909, White). 
On Pinus spp., New Jersey (Newfield, Ellis 2040) ; Washing- 
ton (Seattle, 1906, Bonser 63). 
The type specimen in the State Museum, Albany, N. Y., is 
labeled “on pine limbs in the spring, Newfield, New Jersey, 
/. B. Ellis, no. 2040.” In the original publication it states that 
Mr. Ellis says that the specimen may have been collected in 
Georgia and placed by accident among the New Jersey specimens, 
but it is in the original wrapper and there is strong circum- 
stantial evidence that the inscription on the type specimen is 
correct. 
Distribution : New Jersey to Colorado and Washington, north- 
ward into western Canada. The probable telial stage on Coman- 
dra has a slightly wider range, extending into eastern Canada, and 
into California. 
The study of some fresh specimens which have very recently 
(summer, 1913), come into our hands, together with some data 
accumulated since our previous paper, has resulted in a complete 
change of opinion regarding the standing of this species, Per. 
pyriforme. In his original description Peck laid emphasis on the 
form of the spores which he described as “ obev ate, pyriform, or 
oblong-pyriform, acuminate below, .0015-0025 inch long.’’ We 
had seen the type specimen, which consists of a portion of a branch 
a little more than a centimetre in diameter and about 4 cm. long, 
but we had no opportunity to make a microscopic examination 
of the spores. Never having seen a Peridermium with spores 
such as Peck described, it was only natural that we should assume 
that there was something wrong about Peck’s description. Know- 
ing that peridial cells are sometimes pyriform we came to the con- 
clusion that he probably mistook some of the smaller peridial cells 
