Arthur and Holway: VIOLET RUSTS OF NORTH AMERICA. 641 
have been. As the hosts of these four species of violet rusts 
are found in this country, the rusts may not unreasonably be 
expected also. 
EXPLANATION OF PLATE XLVII. 
All figures photographed and engraved to the same scale, x 250 
diameter. Each millimeter on the plate equals 4 » of original dimen- 
sions. 
Figures.1, 2 and 3. Puccinta Viole showing three sizes of teleuto- 
spores: 1,0n I’. edatzor from Germany, Sydow’s Uredineen, No. 33; 
2, on V. adunca from Gunnison, Colo.; 3, Vola sp. from Mexico, 
Holway No. 3573. 
Figures 4,5 and6. Pauccténta Viole showing especially large teleu- 
tospores: 4,o0n V. d/anda from Lansing, Mich.; 5 and 6, bothon V. 
cognata from Sisson, Calif., taken from different sori. 
Figures 7 and 8. Pucctnta Viole showing especially thick-walled 
uredospores: 7,0n V. glaéde/la from Bingen, Wash.; 8, on V. prému- 
lefolia from Isle au Haut, Me. 
Figures 9 and 10. Puccinia effusa showing regular and irregular 
spores; 9, on V. Nuttallzz from Falcon Valley, Wash.; 10, on V. 
lobata from Dunsmuir, Calif. 
