Arthur: Uredinales on Carex in North America 241 
author’s phanerogamic herbarium, although a few collections had 
been submitted to experts. 
The Carex material for the genus Dicaeorna is now being 
studied. A few specimens from time to time have been sent to 
Dr. Theo. Holm, of Washington, D. C., for critical decision re- 
garding the host. Feeling the great advantage in accuracy that 
would accrue from having all the material examined and com- 
pared under the most favorable conditions, the very generous 
permission of Dr. Holm to submit the full set to him was ac- 
cepted, and in June, 1912, all the material being used as the basis 
for the study of the genus Dicaeorna, together with that previ- 
ously used for the genus Nigredo, was sent, to which was added 
the phanerogamic set of Carex. 
The phanerogamic collection is used as a basis of comparison, 
in order to detect any lapses from a probably correct naming of 
the host. It contains a total of 321 sheets and 133 species, wholly 
from North America, and includes the Olney and Bailey exsic- 
catae. Some of the specimens were determined by Wm. Boott 
and L. H. Bailey, and the Iowa material was once examined by 
R. I. Cratty. It is gratifying to note that Dr. Holm found occa- 
sion to change the names of only five species (nine specimens) 
of this phanerogamic set, all being changes to closely allied spe- 
cies which some authors consider segregates. 
The examination and study of the mycological material was a 
far greater tax upon Dr. Holm’s time and patience, not only be- 
cause of its fragmentary condition but because the opening of 
mycological packets in large numbers is burdensome. 
Of the material submitted, now being used for the genus 
Dicaeorna, there were 645 packets which contained no fruiting 
parts of the host, and such names as collectors have attached to 
them cannot be verified. Of these, however. Dr. Holm questions 
the correctness of 32, either because of the appearance of the 
leaves, or because the locality is outside the known range of the 
species. 
Of the 405 packets submitted, which contained some fruiting 
parts of the host, the larger portion had the specific name of the 
host attached. From a study of this material Dr. Holm found it 
