32 
Mycologia 
about equal numbers in the rusts under consideration. There are 
at present known 63 species with scattered pores and 67 with equa- 
torial pores. Fifteen species have extraequatorial pores, eleven 
Fig. I, a, b, d-l, urediniospores and c, amphispore, all from North Ameri- 
can collections: a, Uromyces Poae, 5 scattered pores; b, c, Puccinia vexans, 
8 scattered pores and 4 equatorial pores; d, P. epiphylla, 10 scattered pores; 
e, P. Cenchri, 2 equatorial pores ; f, P. Urticae, 3 equatorial pores ; g, P. 
poculiformis, 4 equatorial pores ; h, P. eslavensis, 6 equatorial pores ; i, P. 
Caricis-Asteris, 2 superequatorial pores; j, P. Caricis-Strictae, 2 subequatorial 
pores ; k, P. Sporoboli, 3 basal pores ; I, Uromyces nniporulns, i basal pore. 
All spores magnified 625 diameters. 
of which are super- and four subequatorial. Expressed in per- 
centage, the different divisions stand as follows : pores equatorial 
46.2 per cent. ; pores scattered 43.5 per cent. ; pores superequa- 
torial 7.6 per cent. ; pores subequatorial 2.7 per cent. 
None of the grass rusts has superequatorial pores and but a 
single species has subequatorial pores. All of the remaining 
species, therefore, in which the pores are known, belong to the 
scattered- or equatorial-pored groups, 63 species in the former 
group and 42 in the later. 
Among the sedge rusts the scattered-pored condition is very 
uncommon, being found in but a single species, i. e., Ptic. karelica. 
