52 ArtHuR: NEW SPECIES OF UREDINEAE—XV 
small, subepidermal groups, forming a single restricted layer. 
They are small, about 15 by 25y, smooth, with walls evenly 
thin, about ty. The writer can not place this fungus, but be- 
cause of a blackish color, spreading into the surrounding tissues, 
the small size of the spores, and because, if it be assumed that 
they belong with the uredinia, it does not agree with any known 
genus of rusts, it is believed not to belong to the Uredinales. 
Coleosporium aridum H. S. Jackson, sp. nov. 
Oand I. Pycnia and aecia unkno 
II. Uredinia hypophyllous, nantcted or gregarious, small, 
roundish, 0.2-0.3 mm. across, orange-yellow fading to pale- 
yellow, early naked, ruptured epidermis noticeable; uredinio- 
spores globoid or ellipsoid, 16-20 by 20-28u,; wall colorless, 
I-1.5u. thick, closely, finely and uniformly verrucose. 
III. Telia unknown. 
On Coleosanthus californicus (T. & G.) Kuntze (Brickellia 
californica A. Gray) (Carduaceae), Andreas Cafion in the Mojave 
esert, Riverside County, California, March 12, 1922, P. A. 
Munz 4720. The specimen was communicated by Professor 
. C. Blasdale. The material in hand is meager, but indicates 
a strong and characteristic development of the rust. 
Milesia Scolopendrii (Fuckel) comb. nov. 
oo Scolopendrit Fuckel, Jahrb. Nass. Ver. Nat. 
27-28: 1873. 
Uredo Seolopéadrs Schroet. Krypt. Fl. Schles. 3: 374. 1887. 
Uredinopsis Scolopendrit Rostr. Bot. Tidsskr. 21: 42. 1897. 
Melampsorella Blechni Syd. Ann. Myc. 1: 537. 1903. 
Milesina Blechni Syd. Mycoth. Germ. 877. 1910. 
Milesina Scolopendrii Jaap, Fungi Sec. Exsicc. 571. 1912. 
Milesia Blechni Arth. Bot. Gaz. 73: 61. 1922. 
Two forms of a common European rust on certain ferns are 
here united as the result of a careful study of a large number of 
collections. The morphological characters of the two are the 
e. The opinion of the writer regarding their identity is 
also held by Klebahn (Krypt.-fl. Brand Pilze 3: 853), and 
possibly by others. 
The highly absurd claim that de genus Milesia is ‘‘obsolete”’ 
cf. Jour. Bot. 59: 109. 1921), because, as W. B. Grove says) 
(Brit. Rust Fungi, p. 377), “it was founded on an imperfect 
