ARTHUR: NEW SPECIES OF UREDINEAE—XIV 193 
about fifty miles west of Lake Tahoe. Harkness says the fungus 
“appears both on the limbs and trunks of young trees of the 
variety Pinus ponderosa, generally forming a complete circle 
around the trees, its sporidia appearing as a zone of bright 
orange yellow. The spores first germinate beneath the cuticle, 
which it destroys. Owing to the irritation of this presence an 
abnormal thickening of the cambium is produced, which in 
turn gives place to an excessive growth of woody’ fibre. This 
process being repeated from time to time a large bulbous ex- 
pansion is soon formed, so that as often occurs a stem of but an 
inch in diameter is enlarged to that of four or five. Above this 
bulb the further development of the stem is retarded, or arrested 
altogether, its place being supplied by a dense tuft of minute 
branches.’”’ Among other matters it is also stated that “‘in the 
vicinity of Colfax the fungus appears to be limited to an area 
of but a few acres in extent. Within that area, however, it is 
destroying the young growth.” 
The quotation is taken from the report by the secretary of 
the San Francisco society sent to the Monthly Microscopical 
Journal of London, and printed on page 164 in volume 16, 
bearing the date of September 1, 1876. This periodical was 
maintained by the Royal Microscopical Society. 
The name, host and locality are cited in Harkness & Moore’s 
Pacific Coast Fungi in 1880, still without confusion with any 
other form. But when Harkness published technical descriptions 
of “New species of Californian fungi” in the Bulletin of the 
California Academy of Science in 1884, other forms and hosts 
were incorporated, and from this time on the application of the 
name has been various. 
The chief source of confusion has been in failing to rec- 
ognize the Pacific Coast form of Peridermium Cerebrum Peck, 
which occurs along the coast of California, and is especially 
abundant at Monterey on Pinus radiata (P. insignis). The 
present writers feel especially culpable for this confusion, for 
they placed P. Harknessii under P. Cerebrum as a synonym 
in their paper on North American species of Peridermium on 
pine (Mycologia 6: 133. 1914), and have been followed by 
Meinecke, in his paper on Peridermium Harknessii and Cro- 
nartium Quercuum (Phytopathology 6: 225-240. 1916), and 
by others. 
The present knowledge of the Castilleja rusts indicates that 
the correct application of the names should be as follows: 
